Model Rocket Tutorial

Starchaser model rocket

Starchaser model rocket tutorialStarchaser model rocket tutorialStarchaser model rocket tutorialStarchaser model rocket tutorial Pro||||ENGINEER Wildfire 3.0ENGINEER Wildfire 3.0ENGINEER Wildfire 3.0ENGINEER Wildfire 3.0

Schools Advance Edition

WF3M-SAE-L2-001-1

Pro|ENGINEER Wildfire 3.0 Starchaser model rocket

PTC in partnership with

Starchaser Industries Educational Outreach Programme 2 of 104

Written by Mike Brown and the Engineers and staff at

Starchaser Industries Limited

Copyright © 2006, Parametric Technology Corporation (PTC) and Starchaser Industries Limited.

All rights reserved under copyright laws of the United Kingdom, United States and other countries.

PTC, the PTC Logo, ProProProPro|ENGINEER, ProProProPro|DESKTOP, Wildfire, Windchill, and all PTC product names and logos are trademarks or registered trademarks of PTC and/or its subsidiaries in the United States and in other countries.

Conditions of use Copying and use of these materials is authorised only in the schools, colleges and universities of teachers who are authorised to teach ProProProPro|ENGINEER in the classroom.

All other use is prohibited unless written permission is obtained from the copyright holder

Acknowledgements PTC: Andy Deighton, Tim Brotherhood

Feedback

[email protected]

In order to ensure these materials are of the highest quality, users are asked to report errors to the author.

Suggestions for improvements and other activities would also be very welcome.

Product code WF3M-SAE-L2-001-1




Table of ContentsTable of ContentsTable of ContentsTable of Contents Starchaser model rocket tutorialStarchaser model rocket tutorialStarchaser model rocket tutorialStarchaser model rocket tutorial ................................................................................................................................................................................................................................................................................................................................................................................................................................................1111

Table of ContentsTable of ContentsTable of ContentsTable of Contents ....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................3333

Teachers’ notesTeachers’ notesTeachers’ notesTeachers’ notes ................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................5555

Introduction ......................................................................................................................................5

Pre-requisites.....................................................................................................................................5

Abbreviations and terminology used within this tutorial...............................................................................6

Installation and setup..........................................................................................................................6

Pro|ENGINEER functionality addressed in this tutorial................................................................................7

ICT areas addressed in this tutorial........................................................................................................8

D&T subject areas addressed in this tutorial.............................................................................................8

STEM related areas addressed in this tutorial...........................................................................................8

BackgroundBackgroundBackgroundBackground....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................9999

Starchaser IndustriesStarchaser IndustriesStarchaser IndustriesStarchaser Industries ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................9999

Lesson one Lesson one Lesson one Lesson one –––– Product Requirement Product Requirement Product Requirement Product Requirement ............................................................................................................................................................................................................................................................................................................................................................................................................................ 11111111

Learning objectives: ....................................................................................................................... 11

Homework................................................................................................................................... 11

Lesson two Lesson two Lesson two Lesson two ––––........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 11111111


Lesson three Lesson three Lesson three Lesson three –––– Modelling the rocket concept Modelling the rocket concept Modelling the rocket concept Modelling the rocket concept ........................................................................................................................................................................................................................................................................................................................................................................ 13131313


Task 1: Set working directory.............................................................................................................13

Task 2: Creating a new Pro|ENGINEER part ........................................................................................14

Task 3: Creating the rocket concept sketch ...........................................................................................14

Task 4: Dimensioning the Rocket concept sketch ....................................................................................18

Task 5: Defining a geometric relationship .............................................................................................22

Task 6: Assigning the required dimension values....................................................................................24

Task 7: Adding a Datum Planes to the concept......................................................................................25

Task 8: Assigning parameters ............................................................................................................27

Lesson four Lesson four Lesson four Lesson four –––– Top Down Design Top Down Design Top Down Design Top Down Design ........................................................................................................................................................................................................................................................................................................................................................................................................................................ 28282828


Task 9: Creating an Assembly............................................................................................................29

Task 10: Adding the concept part to the assembly .................................................................................30

Task 11: Creating the rocket fuselage..................................................................................................32

Task 12: Assigning material properties and other parameters....................................................................39

Task 13: Modelling the rocket nose cone .............................................................................................41





Task 15: Modelling the Fins ..............................................................................................................53


Task 17: Patterning the Fin ................................................................................................................59

Task 18: Making the Slot for the Fin....................................................................................................60

Task 19: Creating the rocket motor tube...............................................................................................62

Task 20: Adding motor tube to the rocket assembly ................................................................................64

Task 21: Creating the motor tube bulkhead ..........................................................................................66


Task 22: Adding the second bulkhead.................................................................................................70

Lesson five Lesson five Lesson five Lesson five –––– Modelling the Launch Pad Modelling the Launch Pad Modelling the Launch Pad Modelling the Launch Pad ................................................................................................................................................................................................................................................................................................................................................................................................ 73737373


Task 23: Creating the terrain .............................................................................................................73

Task 24: Now for a bit of Rocket Science ............................................................................................76

Task 24: Ready to Launch .................................................................................................................79

Task 25: Simulated Launch................................................................................................................82

Task 26: Additional Activity Suggestions ..............................................................................................86

Appendix AAppendix AAppendix AAppendix A............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 88888888

How to create new Materials.............................................................................................................88

Appendix BAppendix BAppendix BAppendix B ............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 91919191

How to create a new colour ..............................................................................................................91

Appendix CAppendix CAppendix CAppendix C ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ 93939393

How to create the model-rocket motors ................................................................................................93


Task C1: Set Working Directory .........................................................................................................93

Task C2: Modelling the Motor Case ...................................................................................................94

Task C3: Modelling the rocket nozzle..................................................................................................97

Task C4: Modelling the rocket fuel grain..............................................................................................99

Task C5: Assembling the Rocket Motor ..............................................................................................100

Task C6: Adding a Component Interface ...........................................................................................101

Task C7: Adding a Datum Point .......................................................................................................102

Task C8: Defining the Force. ...........................................................................................................103




Teachers’ notesTeachers’ notesTeachers’ notesTeachers’ notes

Introduction

The Starchaser© Model Rocket Tutorial contains basic, intermediate and advanced activities aimed at providing Students with an understanding of the basic Engineering and Scientific concepts used in the design of model rockets. The range of tasks within this tutorial demonstrates the integral roles that Physics, Mathematics and Design & Technology play within the Engineering process.

During these tutorials Users will learn how to create parts and assemblies, understand top-down design within Pro|ENGINEER Wildfire 3.0, and explore Mathematic and Scientific concepts via simulated launches.

This Tutorial and Teacher Resource has been produced as a collaborative initiative between PTC© and Starchaser Industries as part of the PTC Design & Technology in Schools programme.

Pre-requisites

Pro|ENGINEER Wildfire 3.0 Schools Advanced Edition

or

Pro|ENGINEER Wildfire 3.0 University Plus Edition

This tutorial has been developed to explore some of the advanced capabilities of Pro|ENGINEER Wildfire 3.0 Schools Advanced Edition; however the modelling aspects of this tutorial can be conducted in either the Schools Edition or Schools Advanced Edition

This tutorial contains screen and menu images taken from the Schools Advanced Edition so Users of other Pro|ENGINEER Editions may notice some slight differences.

This tutorial has also been based on the use of Pro|ENGINEER start parts & templates supplied as part of the PTC D&T programme. While this tutorial can be used with other Pro|ENGINEER start parts there may be changes required in terms of view orientation, datum plane and coordinate system references etc.

This tutorial requires a basic to intermediate knowledge and experience in Pro|ENGINEER.

Pro|ENGINEER Wildfire requires the use of a 3 button mouse. If possible a mouse with a combined middle wheel & button can improve User interaction with Pro|ENGINEER Wildfire.

The rocket motors supplied used in this tutorial have been created in Pro|ENGINEER Schools Advanced Edition and therefore not compatible with commercial editions.




Abbreviations and terminology used within this tutorial

Left-click Press and release the left-hand mouse button

Left-click-drag Press and hold-down the left-hand mouse button and move the mouse

Right-click Press and release the right-hand mouse button

Right-click-drag Press and hold-down the right-hand mouse button and move the mouse

Middle-click Press and release the middle mouse button

Middle-drag Press and hold-down the middle mouse button and move the mouse

The aim of the tutorial is to introduce students to the basic and intermediate solid-modelling and assembly processes and techniques and analysis functions available in Pro|ENGINEER Wildfire 3.0.

Installation and setup

These Installation notes have been complied based on a directory structure used as part of the PTC D&T programme, the UK CAD in Schools initiative and the deployment of Pro|ENGINEER. Users not part of this programme can still use this tutorial but may need to adapt either their Pro|ENGINEER configuration files or the directory structure used in the tutorial.

The Starchaser Model Rocket Tutorial comes complete with pre-prepared example parts, assemblies and standard parts and requires these files to be loaded prior to the tutorial being delivered.

• Copy the rocket_motorsrocket_motorsrocket_motorsrocket_motors folder into pro_standards/part_libraries/pro_standards/part_libraries/pro_standards/part_libraries/pro_standards/part_libraries/ • Edit the search_path.prosearch_path.prosearch_path.prosearch_path.pro file and add the complete directory path name for the rocket_motors (double click search_path.prosearch_path.prosearch_path.prosearch_path.pro and open with WordPad to edit)

• Copy the material data supplied with this tutorial to pro_standards/material_database/pro_standards/material_database/pro_standards/material_database/pro_standards/material_database/




Pro|ENGINEER functionality addressed in this tutorial.

Sketching

• 2D geometry creation & modification

• Circles, Lines, Rectangles, Arcs, Centrelines, Trimming…

• Sketch Palette

• Sketch References

• Mirror sketch geometry

Geometric & dimensional constraints.

• Weak, Strong & Locked dimensions

• Linear, angular, radial & diameter dimensional constraints

• Geometric constraints, equal, tangent, symmetric.

• Geometric relationships (equation driven dimensions)

Modelling

• Datum Plane creation

• Revolve Feature

• Shell Feature

• Extrude Feature

• Round Feature

• Chamfer

• Patterning (incl. Reference Patterns)

• Warp

• Parametric modification

• Material properties

Assemblies

• Top down assembly modelling

• Assembly constraints

• Hide/Un-hide components

• Component Operations

• Component Instances

Analysis

• Mass Properties

• Definition of a point force




ICT areas addressed in this tutorial

• Modelling

• Communication

D&T subject areas addressed in this tutorial

• CAD

o Parametric feature based solid-modelling

o Assemblies

STEM related areas addressed in this tutorial

• Physics

o Force = mass x acceleration




BackgroundBackgroundBackgroundBackground

Within the diverse range of engineering disciplines and industries perhaps one of the most exciting and challenging areas is aerospace and aeronautical engineering, the epitome of which must surely by the design and manufacture of spacecraft.

The design of a rocket may look basic in terms of its outer geometric shape, but the science and engineering required to produce an aerodynamically stable and light-weight rocket capable of achieving high altitudes is complex; after all it is Rocket Science.

This tutorial will covers the design and assembly of the major components of a model rocket with the subsequent analysis of a simulated launch.

Starchaser IndustriesStarchaser IndustriesStarchaser IndustriesStarchaser Industries

Starchaser Industries is a privately held international company that specialises in the development, operation and commercialisation of space related products and services. Starchaser enables new space related business opportunities by providing safe, reliable, affordable and reusable access to space for both the space tourism and micro-satellite launch markets.

Starchaser Industries have offices in Las Cruces, New Mexico USA and are headquartered in Cheshire England. Since being founded in 1992, by current CEO Steven Bennett, Starchaser have launched a number of reusable launch vehicles (rockets), most notably the NOVA / STARCHASER 4 rocket.

Starchaser Industries also have a long established and highly successful Educational Outreach Programme that engages with both the general public and education. Starchaser’s educational activities complement the national curriculum and help inspire and motivate students at all levels to pursue careers in the fields of Science, Technology, Engineering and Mathematics (STEM). Starchaser provides students with opportunities for involvement in research and development projects to actively promote the STEM subjects and encourage them to pursue higher education at the graduate and doctorate levels.

For more information on Starchaser please visit www.starchaserplc.co.uk

For more information on Starchaser’s Educational Outreach Programme please visit www.space4schools.co.uk




The Starchaser Model Rocket Tutorial comes complete with pre-prepared parts, assemblies and standard parts and requires these files to be loaded prior to the tutorial being delivered. For a full list of files please refer to Appendix XXX.

Starchaser Industries are a PTC Performance Partner and have been using PTC solutions since 1999. Initially Starchaser used Pro|DESKTOP and in 2004 started to deploy Pro|ENGINEER Wildfire. PTC software is used in all aspects of Starchaser’s R&D activities from rocket engines to the airframe of the rockets.




Lesson one Lesson one Lesson one Lesson one –––– Product Requirement Product Requirement Product Requirement Product Requirement

Aim:Aim:Aim:Aim:

During this lesson students should investigate the need for getting into space.

• Why do we need to get into space?

o Human Spaceflight

o Satellites

� Satellite TV & communication

� Earth observation; weather, spy satellites…

o Exploration; the Moon, Mars…

• Where is Space?

• What’s the difference between getting into space and getting to orbit?

Once the reasons for getting into space have been discussed, how do we get into space?

Learning objectives:Learning objectives:Learning objectives:Learning objectives:

By the end of this lesson students should:

• Be aware of the benefits of space.

• Know the milestones in Human spaceflight

• Know the difference between being in space and being in orbit

• Know the planets in our Solar system

• Understand the need for Rockets

This lesson should explore and investigate the need for access to space, the history of space flight, and how to get there.

HomeworkHomeworkHomeworkHomework

Research current rocket designs and technology and also

Lesson two Lesson two Lesson two Lesson two ––––

Aim:Aim:Aim:Aim:




Newton laws of motion





Lesson three Lesson three Lesson three Lesson three –––– Modelling the rocket Modelling the rocket Modelling the rocket Modelling the rocket conceptconceptconceptconcept

Aim:Aim:Aim:Aim:

In this lesson students will learn how to create a 2D concept of the rocket in Pro|ENGINEER Wildfire 3.0



o Know how to create a new part.

o Be able to create valid sketch geometry.

� Lines, centrelines, arcs, and points

� Mirror sketch geometry

� Define sketch dimensions

o Create basic mathematic relationships between sketch dimensions.

o Define new Datum Planes

o Assign project information to parts.

o

Task 1: Set working directory

1. Start Pro|ENGINEER Wildfire

2. In the Navigator Window (down the left-hand side of Pro|ENGINEER) browse to the “rocketrocketrocketrocket” folder

If the Navigator is not displaying Folders

left-click the Folder tab at the top Navigator Window.

3. Right-click the “rocketrocketrocketrocket” folder, and in the menu that appears select Set Working DirectorySet Working DirectorySet Working DirectorySet Working Directory.




Task 2: Creating a new Pro|ENGINEER part

4. From the Pro|ENGINEER top toolbar left-click Create New FilCreate New FilCreate New FilCreate New Fileeee . In the dialog box that appears enter “conceptconceptconceptconcept”

Notice that PartPartPartPart is selected as the default TypeTypeTypeType.

5. Left-click to accept the settings and create the new Pro|ENGINEER part file

When the part opens you should see the default Datum Planes, FRONT, TOP & RIGHT, and the default coordinate system DEFAULT_CSYS displayed in the graphics windows and feature browser.

For the purposes of this activity the DEFAULT_CSYSDEFAULT_CSYSDEFAULT_CSYSDEFAULT_CSYS is not required;

6. From the Pro|ENGINEER top toolbar left-click Coordinate System on/offCoordinate System on/offCoordinate System on/offCoordinate System on/off to turn off the display

Task 3: Creating the rocket concept sketch

During this Task you will create the Rocket concept as a simple 2D sketch.




7. From the Feature Toolbar (down the right-hand side of Pro|ENGINEER)

select the Sketch ToolSketch ToolSketch ToolSketch Tool .

Before you start sketching, Pro|ENGINEER needs to know where to place the Sketch and how it is to be oriented. Pro|ENGINEER will issue a prompt along the bottom of the Pro|ENGINEER

window asking you to:

Pro|ENGINEER will also display the Sketch dialog which captures the selection of Sketch PlaneSketch PlaneSketch PlaneSketch Plane and Sketch OrientationSketch OrientationSketch OrientationSketch Orientation information.

8. In the Pro|ENGINEER Graphics Window move the cursor over the FRONTFRONTFRONTFRONT datum plane and select it with a left-click. This will populate the PlanePlanePlanePlane data box.

Pro|ENGINEER will then automatically suggest/select the TOPTOPTOPTOP datum plane as the ReferenceReferenceReferenceReference Plane to define the Sketch Orientation and Sketch view direction.

9. To accept these references and enter the Sketcher select

Once in the Sketcher, Pro|ENGINEER will automatically reorient the view to look directly

onto the Sketch Plane. If this doesn’t happen, from the top toolbar, left-click to reorient the view.

10. At this point you no longer need to see the Datum Planes or Datum Axes. In the top

toolbar left-click to turn off the display of Datum Planes and to turn off the display of Datum Axes.

Based on the selection of the FRONTFRONTFRONTFRONT datum plane as the sketch plane and the TOPTOPTOPTOP datum plane as the orientation plane, Pro|ENGINEER has automatically created two reference lines in the sketch. The reference lines will be used to position the concept sketch geometry.




Once in the Sketcher Pro|ENGINEER will display the Sketcher Toolbar down the right-hand side.

11. From the Sketcher toolbar select

Create LineCreate LineCreate LineCreate Line

12. Sketch a vertical line (as shown to the right); position the cursor at the position marked XXXX1111 and left-click to start sketching the line. Now move the cursor upwards to the position marked XXXX2222, (as you move the cursor the line will follow, keep the line as close to vertical as possible, you will notice a red letter VVVV which denotes that Pro|ENGINEER will create a vertical line). To place the end of the line left-click.

13. To exit Create Line press the middle mouse button once

(middle-click) or left-click Select ItemSelect ItemSelect ItemSelect Item from the Sketcher toolbar.

14. From the Sketcher Toolbar select Create ArcCreate ArcCreate ArcCreate Arc .

15. Position the cursor over the upper end of the newly created line, (Pro|ENGINEER will snap to the end), left click, XXXX1111, to start the arc and then move the cursor to the position indicated, XXXX2222, (on the vertical reference line) and left-click to create the arc.




The next step is to sketch the fin profile.

16. From the Sketcher toolbar select Create LineCreate LineCreate LineCreate Line .

17. Position the cursor over the bottom end of the vertical line, (Pro |ENGINEER will snap to the end), left click, XXXX1111, to start sketching the fin. Move the cursor onto the horizontal reference line and left-click at the point indicated by XXXX2222.

18. Move the cursor upward and create a vertical line with a left-click at the point indicated by XXXX3333, then move the cursor onto the vertical line and left-click at position XXXX4444. Middle-click to exit Create Line

Don’t worry about any of the dimension values at this point in time.

The geometry created up to now defines just one side of the rocket concept. The next step is to mirror this geometry to complete the rocket concept sketch.

19. In the Sketcher toolbar left-click the small up-turned

arrow to the right of Create LineCreate LineCreate LineCreate Line and from the

pull out menu select Create CentrelineCreate CentrelineCreate CentrelineCreate Centreline .

20. Position the cursor over the vertical reference line and left-click (XXXX1111) to locate the first point of the centreline, now move the cursor upwards and left-click again on the vertical reference line to create the centreline (XXXX2222)




21. Now select all the rocket geometry (excluding the centreline). Hold down the Ctrl key to perform multiple selection.

22. Select Mirror Selected EntitiesMirror Selected EntitiesMirror Selected EntitiesMirror Selected Entities , Pro|ENGINEER

will prompt you to , left-click the newly created centreline.

Notice how Pro|ENGINEER has added some small arrows to indicate symmetry.

23. In the Sketcher toolbar left-click the small up-turned

arrow to the right of Create Create Create Create CentrelineCentrelineCentrelineCentreline , and

select Create Line .

24. Sketch a line across the bottom of the rocket (XXXX1111 & XXXX2222).

Task 4: Dimensioning the Rocket concept sketch




Pro|ENGINEER has automatically created dimensions to fully constrain the geometry. These dimensions are typically grey in colour denoting they are “weakweakweakweak” dimensions.

Note:Note:Note:Note: There are 3 types of sketch dimension;

• LockedLockedLockedLocked – the dimension is locked to its value. This value cannot be modified either directly or indirectly. The dimension has to be un-locked before its value can be modified.

• StrongStrongStrongStrong – the dimension can be modified but only directly by the user

• WeakWeakWeakWeak - the dimension can be modified directly (by explicitly changing the value) or indirectly (by changing other surrounding dimensions/geometry).

While these ‘weakweakweakweak’ dimensions fully constrain the geometry they don’t meet the required dimensioning scheme. The next step is to create the required dimensions.

25. From the Sketcher Toolbar select Create DefinCreate DefinCreate DefinCreate Defining Dimensioning Dimensioning Dimensioning Dimension

.

26. The first dimension will define the Rocket diameter; left-click the left-hand vertical line (XXXX1111) followed by the right-hand vertical line (XXXX2222), and then position the cursor below the Rocket and middle-click to place the dimension (XXXX3333).

NotNotNotNote:e:e:e:

The newly created dimension is a ‘strongstrongstrongstrong’ dimension and is Blue. (colours may vary depending on User defined colour settings)




27. Left-click the bottom line of the Rocket (XXXX1111) and the upper end of the vertical line, (XXXX2222), this end point is referred to as the vertices (the point where two line segments come together), then move the cursor to the left and middle-click to place the dimension (XXXX3333)

28. Left-click the end of the vertical line again (XXXX1111) and then the end point of the arc at the very tip of the Rocket nose (XXXX2222), move the cursor and middle-click to place the dimension (XXXX3333).

Notice as you create ‘strong’ dimensions the ‘weak’ dimension are removed automatically to ensure the geometry is not over constrained.




29. Using these dimensioning techniques create the remaining dimensions shown in the image to completely define the Rocket to the required dimensioning scheme.

Don’t worry about the dimension values at this time, these will be modified later.




Task 5: Defining a geometric relationship

There are many different types of Rocket nose cone, from a simple cone to parabolic.

ConicConicConicConic

Tangent O’giveTangent O’giveTangent O’giveTangent O’give

ParabolicParabolicParabolicParabolic

However one of the most popular nose cones in model rocketry is the ‘Tangent O-give’ (pronounced O-jive).

An O-give nose cone has a specific relationship of 3:1 between the length of the curved nose section to its diameter, i.e. the nose length is 3 x diameter.




30. To create this relationship, from the top toolbar, select ToolsToolsToolsTools>RelationsRelationsRelationsRelations.

Pro|ENGINEER will open the Relations dialog and change the dimensions into ‘symbolic dimensions’, i.e. “sd19” (the numbers will most likely be different in your sketch).

31. To create the required relation first select the length of the curved section of the nose (sd19 in the above image) and build up the relation sd19sd19sd19sd19====3*sd153*sd153*sd153*sd15

• sd19 is the length of the curved section of the nose cone

• sd15 is the overall diameter of the nose cone

32. Left-click to create the new relation.

33. Notice how Pro|ENGINEER modifies the geometry to satisfy this new relationship.




Task 6: Assigning the required dimension values

During the creation of the Rocket concept sketch no specific dimensional values were assigned. The next step is to modify the dimensions to the required values.

34. In the Sketcher Toolbar select Select Items Select Items Select Items Select Items .

35. Double-left-click each dimension value in turn and enter the required dimensions as shown in the adjacent image. After entering the value hit the Return key to enter the value.

NoteNoteNoteNote: you will be unable to modify the nose length dimension as this is driven by the geometric relationship defined in the previous task.

To help in possible future modelling operations the next step is to add a couple of points to the rocket sketch.

36. From the Sketcher toolbar select Create PointCreate PointCreate PointCreate Point . Left-click at the points indicated (XXXX1111 & XXXX2222) to create the required points.




The Rocket concept sketch is now complete.

37. To accept and exit the Sketcher, left-click Accept SketchAccept SketchAccept SketchAccept Sketch .

38. At this point save the part; from the top toolbar select Save Save Save Save FFFFileileileile and in the Save dialog select .

Task 7: Adding a Datum Planes to the concept

To help in the creation and assembly of the individual rocket components the next step is to add additional Datum Planes.

39. From the feature toolbar down the right-hand side of

Pro|ENGINEER select the Datum Plane ToolDatum Plane ToolDatum Plane ToolDatum Plane Tool .

Pro|ENGINEER will now prompt you to select up to 3 references to locate the new Datum Plane.

40. Select the TOPTOPTOPTOP Datum Plane (XXXX1111), then hold down the Ctrl key and select the end of the vertical line where the arc of the nose cone meets the fuselage (XXXX2222)

41. In the Datum Plane dialog box select the PropertiesPropertiesPropertiesProperties tab and enter NOSENOSENOSENOSE for the name.

42. Pro|ENGINEER now has enough information to create and position the new Datum Plane, left-click .




The next step is to repeat this process to create a new Datum Plane at the base of the fuselage.

43. From the feature toolbar down the right-hand side of Pro|ENGINEER select the Datum Plane Datum Plane Datum Plane Datum Plane

ToolToolToolTool .

Pro|ENGINEER will now prompt you to select up to 3 references to locate the new Datum Plane.

44. Select the TOPTOPTOPTOP Datum Plane (XXXX1111), then in Datum Plane dialog position the cursor over References (TOP:F2(DATUM PLANETOP:F2(DATUM PLANETOP:F2(DATUM PLANETOP:F2(DATUM PLANE) and left-click to display the options.

45. left-click the up-turned arrow and select ParallelParallelParallelParallel. This will make the new Datum Plane parallel to the TOP Datum Plane.

46. Now hold down the Ctrl key and select the horizontal line which represents the bottom of the fuselage (XXXX2222).

47. In the Datum Plane dialog box select the PropertiesPropertiesPropertiesProperties tab and enter ENDENDENDEND for the name.

Pro|ENGINEER now has enough information to create and position the new Datum Plane, left-click .

48. At this point save the part; from the top toolbar select Save Save Save Save FFFFileileileile and in the Save dialog select .




Task 8: Assigning parameters

While the rocket concept is finished, in that its geometric form is complete, Pro|ENGINEER can capture other information which is a critical part of the design and engineering process. For this concept part this information will be project information.

49. From the Pro|ENGINEER top toolbar left-click ToolsToolsToolsTools and from the pull-down menu select ParametersParametersParametersParameters.

50. In the Parameter dialog fill in the Values for DESCRIPTION, MODELLED_BY and PROJECT. Click to accept your parameters.

51. The Rocket Concept part is now finished. At this point save the part; from the top toolbar select Save Save Save Save FFFFileileileile and in the Save dialog select .




Lesson four Lesson four Lesson four Lesson four –––– Top Down Design Top Down Design Top Down Design Top Down Design

Aim:Aim:Aim:Aim:

In this lesson students will learn how to undertake Top Down Design in Pro|ENGINEER Wildfire 3.0 and create rocket components



o Understand Top Down Design

o Know how to create an assembly.

o Know how to add existing parts to an assembly

o Know how to create a new component in assembly mode

o Be able to reference geometry from one part to create another.

� Sketch references

� Component Operations

o Understand what sketch based and direct features are.

� Extrude, Revolve, Round, Chamfer, Shell

� Patterns and Reference Patterns

o Assign material properties and project information to parts

o Change the appearance of parts (colour)

o Perform a parametric change and update the assembly and its components.

In industry, it is often best practice to use what is called ‘Top Down Design’; this is where a product is developed from a basic top level concept. Each component part of the final product is typically related in some way to the overall product, for example: a bottle screw cap is related to the diameter of the bottle top.

Top Down Design allows designers and engineers to tie interrelated components together so that if one changes the related components also change. This powerful technique can help maximise the benefits of parametric solid-modelling and assembly modelling where individual components can be designed within the context of the overall assembly.

The first series of Tasks created the 2D layout, or concept of the model rocket, this together with datum planes and datum axes can be used to design and control the individual components such as the nose cone, the fuselage and so on.




Task 9: Creating an Assembly

In this Task you will create the top-level assembly for the rocket and add the 2D concept part.

52. From the Pro|ENGINEER top toolbar left-click Create New FileCreate New FileCreate New FileCreate New File . In the dialog box that appears enter “rocketrocketrocketrocket”

53. Letf-click AssemblyAssemblyAssemblyAssembly to define this new file as an assembly.

Left-click to accept the settings and create the new Pro|ENGINEER assembly file

When the assembly opens you may see the default Datum Planes, ASM_FRONT, ASM_TOP & ASM_RIGHT, and the default coordinate system ASM_DEF_CSYS displayed in the graphics windows and feature browser.

For the purposes of this activity the DEFAULT_CSYSDEFAULT_CSYSDEFAULT_CSYSDEFAULT_CSYS is not required;

54. From the Pro|ENGINEER top toolbar left-click Coordinate System on/offCoordinate System on/offCoordinate System on/offCoordinate System on/off to turn off the display

55. If the Datum Planes aren’t visible left-click Datum PlaneDatum PlaneDatum PlaneDatum Planes on/offs on/offs on/offs on/off to toggle on their display




Task 10: Adding the concept part to the assembly

56. From the assembly toolbar down the right-hand side of Pro|ENGINEER select

Add ComponentAdd ComponentAdd ComponentAdd Component .

57. In the dialog box that appears select conceptconceptconceptconcept.prt.prt.prt.prt then left-click .

Pro|ENGINEER will preview the concept part within the assembly and display the assembly dashboard along the bottom of the Pro|ENGINEER window.

The Dashboard displays the various assembly options, properties, status and prompts.

Pan / Drag:

The newly added component can be moved around within the assembly using the mouse buttons and the Crtl/Alt keys. Spin:

Pro|ENGINEER now needs to be told where to place the newly added part




58. In the Dashboard left-click over AutomaticAutomaticAutomaticAutomatic and

select .

This will position the concept part in the DDDDefaultefaultefaultefault location, where the X0Y0Z0 of the part is positioned on the X0Y0Z0 of the assembly.

59. To accept this assembly location left-click at the right-hand side of the Dashboard.

At this point you don’t need to see the Assembly Datum Planes, ASM_RIGHT, ASM_TOP & ASM_FRONT, or the assembly Datum Axis ASM_DEF_CSYS.

60. In the Model Tree (down the left-hand side of Pro|ENGINEER) select these Assembly Datum Planes and Axis (for multiple select hold down the Ctrl key).

61. Once selected right-click, and from the menu select HideHideHideHide. Pro|ENGINEER will hide these Datum’s in the graphics window and indicate they are hidden by changing the model tree icons.

62. At this point save the assembly; from the top toolbar select Save Save Save Save FFFFileileileile and in the Save dialog select .




Task 11: Creating the rocket fuselage

The fuselage (from the French fuselé “spindle-shaped”) is the main body of either an aircraft or rocket. In larger rockets this section is often referred to as the “booster”

When using top down design you create the part ‘within’ the assembly.

63. From the Pro|ENGINEER feature tool bar select

Create a Component in Assembly ModeCreate a Component in Assembly ModeCreate a Component in Assembly ModeCreate a Component in Assembly Mode

64. In the Component Create dialog enter “fuselagefuselagefuselagefuselage” for the Name and left-click .

Pro|ENGINEER will open up the Create Options dialog.

ImportantImportantImportantImportant: Make sure the Copy FromCopy FromCopy FromCopy From field shows the required template part. This tutorial has been developed to use solid_start_part_mm.prtsolid_start_part_mm.prtsolid_start_part_mm.prtsolid_start_part_mm.prt within the pro_standards directory.

65. If this template is not in the Copy From field left-

click

66. In the Choose TemplateChoose TemplateChoose TemplateChoose Template dialog that appears select solid_start_part_mm.prtsolid_start_part_mm.prtsolid_start_part_mm.prtsolid_start_part_mm.prt and left-click .

67. Once you’ve selected the correct template, in the Create Options dialog left-click

.

If this file isn’t visible you can navigate to the file within the Choose Template dialog.




Pro|ENGINEER will now create a new part and add it to the assembly.

68. You will notice a new set of Datum Planes in the graphics window. Hold down the CtrlCtrlCtrlCtrl and AltAltAltAlt keys and right-click-drag to move the new Fuselage part within the assembly.

Pro|ENGINEER will also display the component placement Dashboard along the bottom the window.

The Fuselage part now needs to be located within the assembly. This will be accomplished by aligning Datum Planes.

69. In the graphics window select the TOPTOPTOPTOP Datum Plane (XXXX1111) of the Fuselage part followed by the ENDENDENDEND Datum plane (XXXX2222) of the Concept part.

Depending on how close these two Datum Planes are Pro|ENGINEER will determine a suitable assembly constraint.

The required result is to align both Datum Planes with no offset (i.e. coincident).

The Dashboard can be used to set the required assembly constraint options.

70. In the Dashboard make sure the AlignAlignAlignAlign option is selected and the constraint

alignment setting is CoincidentCoincidentCoincidentCoincident




71. Now select the FRFRFRFRONTONTONTONT Datum Plane of the Fuselage part followed by the FRONTFRONTFRONTFRONT Datum Plane of the Concept. Again ensuring the Dashboard options are AlignAlignAlignAlign and CoincidentCoincidentCoincidentCoincident.

As assembly constraints are defined Pro|ENGINEER will indicate the status; at this point this will indicate STATUS: Partially ConstrainedSTATUS: Partially ConstrainedSTATUS: Partially ConstrainedSTATUS: Partially Constrained

72. Now select the RIGHTRIGHTRIGHTRIGHT Datum Plane of the Fuselage part and the RIGHTRIGHTRIGHTRIGHT Datum Plane of the Concept part. Again ensuring the Dashboard options are AlignAlignAlignAlign and CoincidentCoincidentCoincidentCoincident.

Pro|ENGINEER now has sufficient information to change the status to Fully ConstrainedFully ConstrainedFully ConstrainedFully Constrained.

73. To accept and finish locating the Fuselage within the assembly left-click AcceptAcceptAcceptAccept from the far right-hand side of the Dashboard.

NoteNoteNoteNote: If at any point during the definition of assembly constraints you inadvertently perform a middle-click Pro|ENGINEER will see this as an Accept ( ), and take you out of component placement.

The component will not be fully constrained, as indicated in the Model Tree by a small

rectangle appearing in front of the component name: .

• To return to component placement and complete the definition of assembly constraints go to the Model Tree and right-click FUSELAGE.PRTFUSELAGE.PRTFUSELAGE.PRTFUSELAGE.PRT, from menu that appears select Edit DefinitionEdit DefinitionEdit DefinitionEdit Definition. This will open up that Dashboard.

• From the top line of the Dashboard select PlaPlaPlaPlacementcementcementcement, this will open up the placement properties dialog

• Left-click New Constraint and then select the required Datum Planes to complete the assembly placement of




the Fuselage.

• When finished left-click AcceptAcceptAcceptAccept


Now that the new empty Fuselage part has been placed in the assembly the Fuselage geometry can be created. At the moment every action is being performed “in” the assembly, the Fuselage geometry needs to be created “in” the Fuselage part.

75. In the Model Tree right-click the FUSELAGE.PRTFUSELAGE.PRTFUSELAGE.PRTFUSELAGE.PRT and from the menu that appears select ActivateActivateActivateActivate. Pro|ENGINEER will change the display of the component within the Model Tree to indicate the Fuselage part is active by display a small green diamond

on the graphic; .

The rocket fuselage will be created with an Extrude Feature. An Extrude is a sketch-based feature and will use a circle which references the rocket 2D concept.

76. From the feature toolbar select CreaCreaCreaCreate Sketchte Sketchte Sketchte Sketch .

77. Pro|ENGINEER will prompt you to

. In the Model Tree select the TOPTOPTOPTOP Datum Plane in FUSELAGE.PRTFUSELAGE.PRTFUSELAGE.PRTFUSELAGE.PRT. (to expand

FUSELAGE.PRT select the ++++ in front of the graphic, as per standard Windows navigation)

Pro|ENGINEER will automatically suggest/select the FRONTFRONTFRONTFRONT datum plane as the ReferenceReferenceReferenceReference Plane to define the Sketch Orientation and Sketch view direction.


Pro|ENGINEER will now reorient the view to look directly onto the Sketch plane and also create two Sketch Reference lines. To help in the creation of the fuselage sketch the view needs to be Isometric.




79. From the top toolbar select Saved View ListSaved View ListSaved View ListSaved View List and from the menu that appears select either IsometricIsometricIsometricIsometric or TrimetricTrimetricTrimetricTrimetric.

To enable the sketch geometry to reference the 2D rocket concept the geometry needs to be brought into the active sketch as a Sketch Reference.

80. The Datum Planes can be turned off, left-click Datum Datum Datum Datum

Planes on/offPlanes on/offPlanes on/offPlanes on/off .

81. From the Pro|ENGINEER top toolbar select SketchSketchSketchSketch and in the pull-down menu that appears select ReferencesReferencesReferencesReferences.

Pro|ENGINEER will open the Sketch References dialog.

Move the cursor over the where one of the points are, Pro|ENGINEER will pre-highlight the point (you may need to look closely).

82. Left-click the point to create the required Sketch Reference (XXXX1111) and repeat the process for the second point (XXXX2222).

83. In the Sketch Reference Dialog left-click .

84. From the Sketcher toolbar select

Create CircleCreate CircleCreate CircleCreate Circle .

85. To Sketch the circle position the cursor over the intersection of the two Reference lines and left-click (XXXX1111), this will be the circle centre. Now move the cursor over one of the points and left-click to create the circle (XXXX2222).

The sketch is now complete.

86. To accept and exit the Sketcher, left-click Accept SketchAccept SketchAccept SketchAccept Sketch .




The next step is to extrude the circle.

87. From the feature toolbar (down the right-hand side of

Pro|ENGINEER), select ExtrudeExtrudeExtrudeExtrude .

Pro|ENGINEER will automatically preview the extrude and display the feature Dashboard.

The fuselage extrude will also be linked to the 2D rocket concept sketch.

88. In the Dashboard select the small up-turned

arrow next to the extrude depth option and from the options select Extrude to Extrude to Extrude to Extrude to

selected point, plane or surfaceselected point, plane or surfaceselected point, plane or surfaceselected point, plane or surface .

89. Move the cursor to the end of the 2D rocket concept line, (Pro|ENGINEER will pre-highlight the vertex), and left-click (XXXX1111) to select it.




At this stage the fuselage extrude is solid but the final fuselage needs to be hollow. There are a number of ways to achieve this result:

o Complete the Extrude Feature and then apply a Shell Feature

o Sketch two concentric circles for the extrude

o Use the ‘Thin’ option

o The ‘Thin’ option creates an extrude with a ‘thin wall’; within this Thin Extrude Feature the wall thickness can be defined either internally, externally of symmetrical about the defining sketch.

90. In the Extrude Feature Dashboard select the ThinThinThinThin option

The Extrude Feature Dashboard will change to show the different options for creating a Thin Extrusion.

While the required wall thickness is 1mm it is often a good idea to enter a larger value so you can see in which direction the Thin is being applied. In this case enter 10mm

91. To step through the different offset direction left-click Change Change Change Change

DirectionDirectionDirectionDirection . The required offset is inside.

92. Once the direction is correct enter a wall thickness of 1mm1mm1mm1mm.

93. To complete the Extrude Feature select Accept FeatureAccept FeatureAccept FeatureAccept Feature at the far right-hand side of the Dashboard.




This stage of the Fuselage design is complete and the geometry has been created within the Rocket assembly and linked to the 2D rocket concept.

94. In the Model Tree right-click the FUSELAGE.PRT and from the menu options that appear select OpenOpenOpenOpen.

Pro|ENGINEER will Open FUSELAGE.PRT as a separate file, i.e. outside of the assembly.

Task 12: Assigning material properties and other parameters

The next step is to assign material and project information.

95. From the Pro|ENGINEER top toolbar select EditEditEditEdit and in menu that appears select Setup…Setup…Setup…Setup…

96. In the Menu Manager that appears (on the right-hand side of the screen) select MaterialMaterialMaterialMaterial.

Pro|ENGINEER will open up the Materials menu.




97. In the Materials menu select “cardboardcardboardcardboardcardboard”.

98. To assign it to the model left-click the right pointing triple arrow , followed by and then in the Menu Manager select DoneDoneDoneDone.

NoteNoteNoteNote: If you can’t see “cardboard” in the list of available materials please refer to Appendix XXAppendix XXAppendix XXAppendix XX

While the rocket fuselage is finished, in that its geometric form is complete, Pro|ENGINEER can capture other information which is a critical part of the design and engineering process. For this concept part this information will be project information.

99. From the Pro|ENGINEER top toolbar left-click ToolsToolsToolsTools and from the pull-down menu select ParametersParametersParametersParameters.

100. In the Parameter dialog fill in the Values for DESCRIPTION, MODELLED_BY and

PROJECT. Click to accept your parameters.

101. The Rocket Fuselage part is now finished. At this point save the part; from the top toolbar select Save Save Save Save FFFFileileileile and in the Save dialog select .




Task 13: Modelling the rocket nose cone

The next task is to model the nose cone, again within context of the rocket assembly.

102. In the Pro|ENGINEER top toolbar left-click WindowWindowWindowWindow and selet ROCKET.ASMROCKET.ASMROCKET.ASMROCKET.ASM. This will display the rocket assembly window.

NOTENOTENOTENOTE: When you have more than one Pro|ENGINEER part and/or assembly open always use the above method for switching between parts. This ensures that Pro|ENGINEER synchronises the part being displayed to the User menu/actions .

Do NOTNOTNOTNOT select the parts from the Microsoft Windows Taskbar along the bottom of your screen.

103. Toggle on the Datum Plane display .


Create a Component in Assembly Mode Create a Component in Assembly Mode Create a Component in Assembly Mode Create a Component in Assembly Mode .

105. In the Component Create dialog enter “nose_conenose_conenose_conenose_cone” for the Name and left-click .


As when creating the Fuselage component: Make sure the Copy FromCopy FromCopy FromCopy From field shows the required template part. This tutorial has been developed to use solid_start_part_mm.prtsolid_start_part_mm.prtsolid_start_part_mm.prtsolid_start_part_mm.prt within the pro_standards directory.

106. Once you’ve selected the correct template, in the Create OptionsCreate OptionsCreate OptionsCreate Options dialog left-click .




Pro|ENGINEER will now create a new part and add it to the assembly.

107. You will notice a new set of Datum Planes in the graphics window. Hold down the CtrlCtrlCtrlCtrl and AltAltAltAlt keys and right-click-drag to move the new nose_cone part within the assembly.

Pro|ENGINEER will also display the component placement Dashboard along the bottom the window.

The nose_cone part now needs to be located within the assembly. As with the Fuselage, this will be accomplished by aligning Datum Planes.

108. In the graphics window select the TOPTOPTOPTOP Datum Plane (XXXX1111) of the nose_cone followed by the NOSENOSENOSENOSE Datum Plane (XXXX2222) of the Concept part.

Depending on how close these two Datum Planes are Pro|ENGINEER will determine a suitable assembly constraint.

The required result is to align both Datum Planes with no offset (i.e. coincident)

The Dashboard can be used to set the required assembly constraints.

109. In the Dashboard make sure the AlignAlignAlignAlign option is selected and the constraint

alignment setting is CoincidentCoincidentCoincidentCoincident




110. Now select the FRONTFRONTFRONTFRONT Datum Plane of the nose_cone part and the FRONTFRONTFRONTFRONT Datum Plane of the Concept part. Again ensuring the Dashboard options are AlignAlignAlignAlign and CoincidentCoincidentCoincidentCoincident.

111. Finally select the RIGHTRIGHTRIGHTRIGHT Datum Plane of the nose_cone part and the RIGHTRIGHTRIGHTRIGHT Datum Plane of the Concept part. Once more ensuring AlignAlignAlignAlign and CoincidentCoincidentCoincidentCoincident.

112. To accept and finish locating the nose_cone left-click AcceptAcceptAcceptAccept for the far right of the Dashboard.


The next step is to create the nose cone geometry. Pro|ENGINEER is currently active in the assembly so the NOSE_CONE.PRT needs to be activated

114. In the Model Tree right-click the NOSE_CONENOSE_CONENOSE_CONENOSE_CONE.PRT.PRT.PRT.PRT and from the menu that appears select ActivateActivateActivateActivate. Pro|ENGINEER will change the display of the compoent within the Model Tree to indicate the Fuselage part is active by display a small green diamond

on the graphic; .

The nose cone will be created using a Revolve Feature. A Revolve is a sketch-based feature and will use a 2D profile based which will reference both the concept geometry and the fuselage.

115. From the feature toolbar select Create SketchCreate SketchCreate SketchCreate Sketch .

116. Pro|ENGINEER will prompt you to . In the Model

Tree select the FRONTFRONTFRONTFRONT Datum Plane in NOSE_CONENOSE_CONENOSE_CONENOSE_CONE.PRT.PRT.PRT.PRT. (to expand NOSE_CONE.PRT

select the ++++ infront of the graphic, as per standard Windows navigation)

Pro|ENGINEER will automatically suggest/select the TOPTOPTOPTOP datum plane as the ReferenceReferenceReferenceReference Plane to define the Sketch




Orientation and Sketch view direction.


Pro|ENGINEER will now reorient the view to look directly onto the Sketch plane and also create two Sketch Reference lines.

At this point the Datum Planes are no longer required.

118. Left-click Datum Planes on/offDatum Planes on/offDatum Planes on/offDatum Planes on/off .

The nose cone will directly reference geometry within the 2D concept and the fuselage model.

119. To help in the selection of the required reference geometry zoom in to the nose and

from the Top Toolbar left-click Wireframe HiddenWireframe HiddenWireframe HiddenWireframe Hidden to change the the view display

120. From the Top Toolbar select Sketch>ReferencesSketch>ReferencesSketch>ReferencesSketch>References and move the cursor over the fuselage model until the inner edge highlights and the left-click (XXXX1111). This will create a new reference line in the nose cone part which will always be linked to the fuselage via the assembly.




The next step is to bring the arc for the nose cone into the sketch nose cone.

121. From the Feature Toolbar select Create Entity from EdgeCreate Entity from EdgeCreate Entity from EdgeCreate Entity from Edge and select the arc (XXXX1111), then in the TypeTypeTypeType dialog select close.

In industry there is often a difference between the design concept and the actual manufactured component. For example in the case of the nose cone, the 2D concept has the nose coming to a sharp point, however to manufacture the mould tool required to create a plastic nose cone with such a sharp point would difficult and costly. Also such a sharp point would soon become damaged during use.

Manufacture of the nose cone mould tool would be easier if the nose didn’t come to such a sharp point and as long as the aerodynamic properties were’nt compromised the design change is acceptable. This type of design change is often referred to as “Design for Manufacture” and is an important part of the engineering process.

Using the Top Down approach the nose cone production part can be modelled to better suit manufacturing and in-service requirements. In this case this means adding a small round on the nose cone point.

122. From the sketch toolbar select Create Circle

.

123. Poisition the cursor over the vertical reference line just below the point of the 2D nose cone and left-click to position the circle’s centre (XXXX1111). Move the cursor onto the arc until you see TTTT which indicate a Tangent constraint will be created, and left click to create the circle (XXXX2222).

124. From the sketch toolbar left-click Select ItemsSelect ItemsSelect ItemsSelect Items

to exit Create Cirlce.

Don’t worry about the dimension just yet.




To achieve the required result some geometry needs to be removed.

125. From the Sketch Toolbar select Dynamically Dynamically Dynamically Dynamically

Trim section entitiesTrim section entitiesTrim section entitiesTrim section entities (often referred to as Squiggle Trim).

Pro|ENGINEER will display small dots which indicate geometry segments, i.e. the geometry between the dots. The Squiggle Trim will remove any segment geometry.

126. Left-click-drag and move the cursor over each of the line segments that needs to be removed/trimmed, (as shown).




The next step is to sketch the part of the nose cone that will attach it to the fuselage. In this case the nose cone will have a slide fit into the fuselage.

In model rocketry the parachute is typically deployed from the top of the fuselage: The rocket motor propells the rocket skyward and when all the rocket propellant is consumed the rocket continus to coast upward.

The rocket motor has a small delay composition which starts burning leaving a trail of smoke to help track your rocket. When the delay composition is fully consumed it ignites what’s called the ejection charge. This fast burning ejection charge overpressurises the fuselage and pushes the nose cone off and the parachute out.

It is therefore important that the nose cone fits nicely into the fuselage.

127. Zoom into the area around the top of the fuselage.

128. From the Sketch Toolbar Select Create LineCreate LineCreate LineCreate Line

.

129. Start the line at the end of the main nose cone arc (XXXX1111) and then move along the horizontal reference line (XXXX2222) (futher inside the fuselage reference line), then vertcally down (XXXX3333) and then horizontally onto the main vertical reference line (XXXX4444).

130. While still in Create Line, zoom out so you can see the top of the nose cone and select the end of the small arc (XXXX5555).

131. From the Sketch Toolbar left-click Select ItemsSelect ItemsSelect ItemsSelect Items to exit Create Line.




The nest step is to create the required dimensioning scheme with the correct values.

132. From the Sketch tollbar select Create Defining

Diemnsions ad using the same techniqes used to dimension the Rocket Concept create the required dimensions with the correct values.

The dimension between the inside of the fuselage and the nose cone insert is set to 0.25mm0.25mm0.25mm0.25mm, this will allow the nose cone to slide in and out of the fuselage.

As the nose cone geometry references the fuselage geometry if the fuselage changes diameter so will the nose cone.

The nose cone point has a radius of 1.5mm1.5mm1.5mm1.5mm, this will still produce an aerodynamic nose cone but without the sharp point.




The last thing to do is create a centreline.

133. From the Sketcher toolbar left-click the small up-turned arrow

to the right of Create LineCreate LineCreate LineCreate Line and from the pull-out menu

select Create CentrelineCreate CentrelineCreate CentrelineCreate Centreline .

134. Create the Centreline along the main vertical reference line (XXXX1111XXXX2222).

The nose cone sketch is now complete.

135. From the Sketch Toolbar left-click Accept SketchAccept SketchAccept SketchAccept Sketch

136. From the Feature Toolbar select RevolveRevolveRevolveRevolve .

Pro|ENGINEER will automatically preview the Revolve and display the feature Dashboard.

(If nothing happens, select the newly created sketch, if nothing happens you may need to go back into the sketch using Edit Definition and check the sketch profile.)

137. To complete the Revolve Feature select Accept FeatureAccept FeatureAccept FeatureAccept Feature at the far right-hand side of the Dashboard.

The next step is to add additional features to the nose cone. These features can be created outside of the assembly.

138. In the Model Tree right click and from the pull-down menu select ActivateActivateActivateActivate.




The next step is to change the colour of the nose cone.

139. From the Pro|ENGINEER Top Toolbar select ViewViewViewView and from

the pull down menu select .

140. Select the desired colour from the list followed by .

141. To close the Appearance Editior select

For information on how to create colours please refer to For information on how to create colours please refer to For information on how to create colours please refer to For information on how to create colours please refer to Appendix BAppendix BAppendix BAppendix B




To aid insertion of the nose cone into the fuselage a small radius will be added to the insert section.

142. From the Feature Toolbar select RoundRoundRoundRound

143. Left-click the bottom edge of the nose cone and set the value to 2222mmmmmmmm

144. To complete the Round Feature select Accept FeatureAccept FeatureAccept FeatureAccept Feature at the far right-hand side of the Dashboard.

At the moment the nose cone is solid. The required nose is hollow.

145. From the Feature Toolbar select ShellShellShellShell . Make sure no geometry is select to ensure the Shell will be applied to the entire nose cone. Enter a value of 1.5mm1.5mm1.5mm1.5mm for the shell thickness and make sure it’s applied to the inside of the nose.

146. To complete the Round Feature select Accept FeatureAccept FeatureAccept FeatureAccept Feature at the far right-hand side of the Dashboard.





The next step is to assign material and project information.

147. From the Top Toolbar select EditEditEditEdit and in the menu that appears select Setup…Setup…Setup…Setup…

148. In the Menu Manager select MaterialMaterialMaterialMaterial

149. Pro|ENGINEER will open up the Material menu. Select LDPE.mat (Low Density PolyEthelen).

150. To assign the material to the model left-click the right pointing

tripple arrow , followed by and then in the Menu Manager select DoneDoneDoneDone.

151. From the Top Toolbar select ToolsToolsToolsTools and from the menu select ParametersParametersParametersParameters....

152. In the Parameter dialog enter the values for DESCRIPTION, MODELLED_BY and PROJECT. Left-click to accept the parameters.

153. The Rocket Nose Cone part is now finished. At this point save the part; from the top toolbar select Save Save Save Save FFFFileileileile and in the Save dialog select .




Task 15: Modelling the Fins

When designing a rocket one of the most important issues is rocket stability. In the large commercial rocket this is achieved with “active guidance” which in some case is where the rocket engine moves to influence the direction of flight.

In model rocketry stability is usually achieved by adding Fins. The fins provide what is called “passive stability”. Fins provide stability by using the air that flows over them during flight to keep the rocket flying stable.

While there are a number of other important issues relating to rocket stability, such as Centre-of-Gravity and Centre-of-Pressure, we will ignore these for the purposes of this tutorial.




155. Toggle on the Datum Plane display .

The rocket fins will be created in the same manner as the fuselage and nose cone, within the context of the assembly.

At this stage we don’t need to see the nose cone or the fuselage.

156. In the Model Tree right-click on FUSELAGE.PRTFUSELAGE.PRTFUSELAGE.PRTFUSELAGE.PRT and from the menu select HideHideHideHide.

157. Repeat this process for the NOSE_CONE.PRTNOSE_CONE.PRTNOSE_CONE.PRTNOSE_CONE.PRT and the assembly Datum Planes.





Create a Component in AsCreate a Component in AsCreate a Component in AsCreate a Component in Assembly Modesembly Modesembly Modesembly Mode .

In the Component Create dialog enter “finfinfinfin” for the Name and left-click .


As when creating the Fuselage & nose cone components: Make sure the Copy FromCopy FromCopy FromCopy From field shows the required template part. This tutorial has been developed to use solid_start_part_mm.prtsolid_start_part_mm.prtsolid_start_part_mm.prtsolid_start_part_mm.prt within the pro_standards directory.

Once you’ve selected the correct template, in the Create OptionsCreate OptionsCreate OptionsCreate Options dialog left-click .

159. Pro|ENGINEER will now create the new part and add it to the assembly. Using the same techniques used to assemble the fuselage part into the assembly select the relevant Datumn Planes pairs:

• Fin TOPTOPTOPTOP Datum Plane to Concept ENDENDENDEND Datum Plane (AlignAlignAlignAlign & CoincidentCoincidentCoincidentCoincident)

• Fin FRONTFRONTFRONTFRONT Datum Plane to Concept FRONTFRONTFRONTFRONT (AlignAlignAlignAlign & CoincidentCoincidentCoincidentCoincident)

• Fin RIGHTRIGHTRIGHTRIGHT Datum Plane to Concept RIGHTRIGHTRIGHTRIGHT (AlignAlignAlignAlign & CoincidentCoincidentCoincidentCoincident)

160. To accept and finish locating the new Fin part within the assembly left-click AcceptAcceptAcceptAccept .

161. In the Model Tree right-click the FINFINFINFIN.PRT.PRT.PRT.PRT and from the menu that appears select ActivateActivateActivateActivate. Pro|ENGINEER will change the display of the component within the Model Tree to indicate the Fuselage part is active by display a small green diamond

on the graphic;




The Fin will be created using a Extrude Feature. An Extrude is a sketch-based feature and will use a 2D profile based which will reference both the concept geometry.

162. From the feature toolbar select Create SketchCreate SketchCreate SketchCreate Sketch .

163. Pro|ENGINEER will prompt you to Select the

FRONTFRONTFRONTFRONT Datum Plane in FINFINFINFIN.PRT.PRT.PRT.PRT. (to expand FIN.PRT select the ++++ infront of the graphic, as per standard Windows navigation)

Pro|ENGINEER will automatically suggest/select the TOPTOPTOPTOP datum plane as the ReferenceReferenceReferenceReference Plane to define the Sketch

164. From the Feature Toolbar select Create Entity from Create Entity from Create Entity from Create Entity from

EdgeEdgeEdgeEdge and select the fin geometry indicated (XXXX1111, X, X, X, X2222, , , ,

XXXX3333), then in the TypeTypeTypeType dialog select .

The Fin will attach to the fuselage with a tab that will be inserted into a slot down the side of the fuselage (not yet modelled).

165. Sketch the tab geometry as shown using Create LineCreate LineCreate LineCreate Line

.

The tab will be controlled by both geometric and dimensional constraints.




166. In the Sketch Toolbar select Impose Sketch ConstraintsImpose Sketch ConstraintsImpose Sketch ConstraintsImpose Sketch Constraints

.

167. In the Constraints dialog select Create Equal LengthsCreate Equal LengthsCreate Equal LengthsCreate Equal Lengths and select the two small verical lines (XXXX1111, XXXX2222), and

left-click .

168. In the Sketch Toolbar select Create Defining Create Defining Create Defining Create Defining

DimensionsDimensionsDimensionsDimensions and add the two dimension shown.

The use of geometric constraints ensures the tab will remain central to the Fin.

169. The Fin sketch is now complete, from the Sketch Toolbar left-click Accept SketchAccept SketchAccept SketchAccept Sketch .

The next step is to extrude the sketch into a solid.

170. To help see the extrude better change the view orientation to either Isometric or Trimetric.




171. From the Feature Toolbar select Extrude Feature .

Pro|ENGINEER automatically preview the extrude an open the feature Dashboard.

The solid needs to be extruded each side of the sketch to create the required Fin.

172. In the feature Dashboard change the depth options to

Symmetrical , change the depth value to 3mm3mm3mm3mm.

173. To complete the feature select Accept FeatureAccept FeatureAccept FeatureAccept Feature from the far right of the Dashboard.

To help the Fin pass through the air the leading edge will be chamfered.

174. From the Feature Toolbar select Chamfer Tool .

Pro|ENGINEER will display the Chamfer Dashboard. There are different options for Chamfer as shown in the illustration. For the purposes of the Fin leading edge a D1xD2 chamfer will be applied.




175. Select the required D1xD1xD1xD1x D2D2D2D2 option and select the two top edges of the Fin (hold down the Ctrl key for multiple select).

176. Using either the drag handles or by entering the values in the Dashboard set the chamfer offsets to 5mm x 1.5mm.



178. In the Model Tree, left-click FIN.PRTFIN.PRTFIN.PRTFIN.PRT and from the menu select ActivateActivateActivateActivate

179. As done previously with the Fuselage and Nose Cone, assign a material to the Fin, (Balsa_wood).

180. Now define the other part Parameters; DESCRIPTION, MODELLED_BY, andn PROJECT.

181. You may also wish to change the colour of the part.

182. The Fin part is now finished. At this point save the part.




Task 17: Patterning the Fin




184. At this point the 2D Concept is no longer required. In the Model Tree right-click CONCEPT.PRTCONCEPT.PRTCONCEPT.PRTCONCEPT.PRT and from the menu that appears select HideHideHideHide.

At the moment there is only one fin in the assembly. The next step is to pattern the Fin.

185. The pattern will require an axis; from the Top Toolbar select

Display Axes on/offDisplay Axes on/offDisplay Axes on/offDisplay Axes on/off

186. In the Model Tree select FIN.PRTFIN.PRTFIN.PRTFIN.PRT and in the Feature Toolbar

select PatternPatternPatternPattern .

Pro|ENGINEER will display the Pattern Dashboard.

187. Change the Pattern Type to AxisAxisAxisAxis [ 1111 ] and select the Axis of the rocket (XXXX1111)

188. Change the Number Of Patern MembersNumber Of Patern MembersNumber Of Patern MembersNumber Of Patern Members to 4444 [ 2222 ]

189. Select the Equally SEqually SEqually SEqually Spacepacepacepacedddd option [ 3333 ]





Task 18: Making the Slot for the Fin

The rocket now has 4 Fins around the Fuselage but the Fuselage doesn’t have any slots to take the Fin tabs.

Continuing the Top Down design methodology the slots in the Fuselage will be created directly from the Fin tab within the context of the overall Rocket assembly.

191. From the Pro|ENGINEER Top Tollbar select EditEditEditEdit and from the menu that appears select Component OperationsComponent OperationsComponent OperationsComponent Operations

192. In the Menu Manager select Cut OutCut OutCut OutCut Out

Along the bottom of, in the User prompt section Pro|ENGINEER is

prompting; .

193. Select the Fuselage, then select in the small selection dialog.

Pro|ENGINEER prompts:

194. Select the Fin. (Make sure you select the first Fin in the pattern, you can do this by selecting the fin in the Model Tree by expanding the Pattern Feature). Again select in the small selection dialog

195. To execute the operation select DoneDoneDoneDone, in the intermediate dialog followed by Done/ReturnDone/ReturnDone/ReturnDone/Return in the Menu Manager

196. To see the result expand the Pattern Feature in the Model Tree and select all 4 Fins (left-click and hold down the Ctrl key), then right-click and select HideHideHideHide from the menu.

The next step is to pattern this slot. Rather than apply a normal pattern Pro|ENGINEER has the ability to create a Reference Pattern, this is where one pattern follows a previous pattern, i.e. the slot pattern will follow the Fin pattern.




197. In the Model Tree expand the FUSELAGE.PRT and select the newly created slot .

198. In the Feature Toolbar select Pattern .

199. Pro|ENGINEER will automatically detect there is already a pattern related to the Fin which created the slot and selects a ReferenceReferenceReferenceReference for the Pattern Type.


201. To see the benefit of this Top Down approach right-click the Fin pattern in the Model Tree. From the menu that appears select EditEditEditEdit.

202. In the graphics window double-left-click the text 4 4 4 4 COMPONENTSCOMPONENTSCOMPONENTSCOMPONENTS and change the number to 3 (hit the return key to enter the new value).




203. From the Top Toolbar select Regenerate Model .

Pro|ENGINEER will regenerate the model to have just 3 Fins and also change the slot pattern in the Fuselage.

204. In the Model Tree un-hide the Fins.


Task 19: Creating the rocket motor tube

The main body of the model rocket is now complete. The next steps will create the internal structure to hold the rocket motor.

The rocket motor will be held in a small tube.

206. From the Pro|ENGINEER top toolbar left-click Create New FileCreate New FileCreate New FileCreate New File . In the dialog box that appears enter “motor_tubemotor_tubemotor_tubemotor_tube”

Make sure that PartPartPartPart is selected as the default TypeTypeTypeType.

Left-click to accept the settings and create the new Pro|ENGINEER part file




207. Create a new SketchSketchSketchSketch, selecting the TOPTOPTOPTOP Datum Plane for the Sketch Plane.

208. Sketch a cirlce with it’s centre at the intersection of the two default reference lines.

209. Change the diameter dimension to 18.2mm18.2mm18.2mm18.2mm.

210. The motor_tube Sketch is now complete, from the Sketch Toolbar left-

click Accept SketchAccept SketchAccept SketchAccept Sketch .

211. ExtrudeExtrudeExtrudeExtrude the Sketch to a depth of 70mm70mm70mm70mm and select the ThinThinThinThin

option , giving it a wall thickness of 1mm1mm1mm1mm on the outsideoutsideoutsideoutside of the extrude, , (thus maintaining an internal diameter of 18.2mm18.2mm18.2mm18.2mm).


213. Assign ‘cardboard’cardboard’cardboard’cardboard’ as the material.

214. Now define the other part Parameters; DESCRIPTION, MODELLED_BY, and PROJECT.

215. You may also wish to change the colour of the part.

Pro|ENGINEER has the ability to automate the assembly of components using Component Interfaces, these tell Pro|ENGINEER how to assembly components together. The next step is to create a Component Interface to help automate the assembly of the rocket motor into the rocket assembly.

216. Toggle on the display of Datum Axes,

217. From the Top toolbar select InsertInsertInsertInsert and from the menu that appears select Model Model Model Model

Datum Datum Datum Datum then

Pro|ENGINEER will now prompt:




218. Select the outer cylindrical face of the motor tube (XXXX1111) and then select the end face of the tube (XXXX2222).

219. For the end face the required Constraint TypeConstraint TypeConstraint TypeConstraint Type is AlignAlignAlignAlign and the OffsetOffsetOffsetOffset in CoincidentCoincidentCoincidentCoincident.

220. In the Component Interface dialog left-click the default name (INTF001) and change this to MOTORMOTORMOTORMOTOR.

221. Select to accept these settings.

The Motor Tube is now complete, save the part; from the top toolbar select Save Save Save Save FFFFileileileile

and in the Save dialog select .

Task 20: Adding motor tube to the rocket assembly




222. Open the rocket assembly.

223. From the Feature Toolbar select

Add Component . In the dialog that appears select the motor_tube.prtmotor_tube.prtmotor_tube.prtmotor_tube.prt

Pro|ENGINEER will preview the newly added component.

The Dashboard will display different options to those seen previously as there is a component interface in the motor_tube part.

224. To assemble the motor tube first select the cylindrical face of the fuselage then the end face of the fuselage.

You will notice that the use of a component interface removes the need to select geometry on the motor tube.

225. To accept and finish locating the motor tube part within the assembly left-click AcceptAcceptAcceptAccept .




Task 21: Creating the motor tube bulkhead

The motor tube is currently not attached to the rocket fuselage, this will be achieved by adding bulkheads. The bulkheads will be created within the assembly using a revolve feature.

To help in the creation and initial assembly placement of the bulkhead part, components and geometry that is not required for the assembly process will be hidden.

226. In the Model Tree select all the parts except the motor_tube.prt, (hold down the Ctrl key and left-click for multiple select) and right-click to bring up the menu. Select HideHideHideHide.

227. Also select the assembly Datum Planes, ASM_RIGHT, ASM_TOP, ASM_FRONT and ASM_DEF_CSYS, and hide these.

228. From the Feature Toolbar select Create a Create a Create a Create a

Component in assembly mode Component in assembly mode Component in assembly mode Component in assembly mode .

229. In the Component Create dialog enter “bulkheadbulkheadbulkheadbulkhead” for the Name and left-click .

230. As done previously; make sure the template part is solid_start_part_mm.prtsolid_start_part_mm.prtsolid_start_part_mm.prtsolid_start_part_mm.prt, then select .




231. Pro|ENGINEER will now create the new part and add it to the assembly. Using the same techniques used to assemble the fuselage and fin parts into the assembly select the relevant Datumn Planes pairs:

• Bulkhead FRONTFRONTFRONTFRONT Datum Plane to motor_tube FRONTFRONTFRONTFRONT (AlignAlignAlignAlign & CoincidentCoincidentCoincidentCoincident)

• Bulkhead RIGHTRIGHTRIGHTRIGHT Datum Plane to motor_tube RIGHTRIGHTRIGHTRIGHT (AlignAlignAlignAlign & CoincidentCoincidentCoincidentCoincident)

• Bulkhead TOPTOPTOPTOP Datum Plane to motor_tube TOPTOPTOPTOP (AlignAlignAlignAlign WITH WITH WITH WITH ANANANAN OffsetOffsetOffsetOffset of 5mm5mm5mm5mm)

232. To accept and finish locating the new Bulkhead part within the assembly left-click AcceptAcceptAcceptAccept .

The next step is to create the bulkhead using geometry from both the motor tube and fuselage.

233. In the Model Tree right-click the fuselage.prtfuselage.prtfuselage.prtfuselage.prt and from the menu select UnhideUnhideUnhideUnhide.

234. Still in the Model Tree right-click the new Bulkhead part and from the menu select ActivateActivateActivateActivate.

Pro|ENGINEER will change the display of the component within the Model Tree to indicate the Fuselage part is active by display a small green diamond on the graphic.

235. At this point the Datum Planes are no longer required. From the Top Toolbar toggle the display of Datum

Planes .

236. From the Feature Toolbar select Create Sketch .

Before you start sketching, Pro|ENGINEER needs to know where to place the Sketch and how it is to be oriented. Pro|ENGINEER will issue a prompt along the bottom of the




Pro|ENGINEER window asking you to:

Pro|ENGINEER will also display the Sketch dialog which captures the selection of Sketch PlaneSketch PlaneSketch PlaneSketch Plane and SketSketSketSketch ch ch ch OrientationOrientationOrientationOrientation information.

237. In the Model Tree select the Bulkhead FRONTFRONTFRONTFRONT Datum Plane. This will populate the PlanePlanePlanePlane data box.


238. To accept these references and enter the Sketcher

select .

239. The bulkhead will reference the fusealge and the motor tube, to help selecting the required geometry change the model

display to Hidden LineHidden LineHidden LineHidden Line .

240. From the Top Toolbar select SketchSketchSketchSketch and from the menu that appears select ReferencesReferencesReferencesReferences.

Pro|ENGINEER will open the the Sketch References dialog.

241. Select the line which represents the inside of the fuselage (XXXX1111) and the line which represents the outside of the motor tube (XXXX2222).

And select .

242. From the Sketcher Toolbar select

Create RectangleCreate RectangleCreate RectangleCreate Rectangle .

243. Start the rectangle at the intersection of reference lines with the motor_tube (XXXX1111) and then move th cursor onto the reference line created from the inside of the fuselage (XXXX2222).




244. Dimension the rectangle and give it a value of 1.5mm1.5mm1.5mm1.5mm

245. Create a centreline on the vertical reference line indicated.

246. The Sketch is now complete, left-click Accept SketchAccept SketchAccept SketchAccept Sketch .

247. Change the view display back to

ShadedShadedShadedShaded .


RevolveRevolveRevolveRevolve .

Pro|ENGINEER will automatically preview the Revolve and display the feature Dashboard.

(If nothing happens, select the newly created sketch, if nothing happens you may need to go back into the sketch using Edit Definition and check the sketch profile.)

249. To complete the Revolve Feature select Accept FeatureAccept FeatureAccept FeatureAccept Feature at the far right-hand side of the Dashboard.





250. In the Model Tree, left-click BULKHEAD.PRTBULKHEAD.PRTBULKHEAD.PRTBULKHEAD.PRT and from the menu select ActivateActivateActivateActivate.

251. Assign the required material (cardboard)

252. Define the other part parameters; DESCRIPTION, MODELLED_BY, and PROJECT.

253. You may wish to change the part colour.

254. The Bulkhead part is now finished. At this point save the part.

Task 22: Adding the second bulkhead

The motor tube needs two bulkheads to securely locate it within the fuselage.

255. From the Top Toolbar select WindowWindowWindowWindow and from the make sure the ROCKET.ASMROCKET.ASMROCKET.ASMROCKET.ASM is the active window.

256. In the Model Tree right-click the FUSELAGE.PRTFUSELAGE.PRTFUSELAGE.PRTFUSELAGE.PRT and from the menu that appears select HideHideHideHide.


Add Component .

258. In the Add ComponentAdd ComponentAdd ComponentAdd Component dialog double-left-click the bulkhead.prtbulkhead.prtbulkhead.prtbulkhead.prt.

Pro|ENGINEER will preview the part and prompt:




259. Select the outer cylindrical face of the motor tube followed by the small inner corresponding face of the new bulkhead part.

260. Then select the end face to the motor tube and the corresponding face of the bulkhead and create an AlignAlignAlignAlign and CoincidentCoincidentCoincidentCoincident assembly constraint

The motor tube is now securely located within the fuselage.

261. In the Model Tree unhide the other rocket components.

To complete the model rocket assembly all that needs to be done is add the rocket motor


Add Component and in the Add Component browse to the rocket_motors folder and double click the B_MOTOR.PRT.


As both the B_MOTOR and MOTOR_TUBE contain a corresponding Component Interface the assembly of the motor is automated.




263. In the graphics window select the white circle.

Pro|ENGINEER will assemble the B_MOTOR based on the predefined assembly constraints held with the Component Interfaces.

264. To accept and the assembly location left-click AcceptAcceptAcceptAccept .

The Model Rocket assembly is now complete.

265. Save the assembly




Lesson five Lesson five Lesson five Lesson five –––– Modelling the Launch PModelling the Launch PModelling the Launch PModelling the Launch Padadadad

Aim:Aim:Aim:Aim:



Task 23: Creating the terrain

266. From the Pro|ENGINEER top toolbar left-click Create New FileCreate New FileCreate New FileCreate New File . In the dialog box that appears enter “launch_padlaunch_padlaunch_padlaunch_pad”

267. Left-click to accept the settings and create the new Pro|ENGINEER part file

268. From the Feature Toolbar select Sketch Tool .

Before you start sketching, Pro|ENGINEER needs to know where to place the Sketch and how it is to be oriented. Pro|ENGINEER will issue a prompt along the bottom of the

Pro|ENGINEER window asking you to:

269. Select the TOPTOPTOPTOP Datum Plane for the Sketch PlaneSketch PlaneSketch PlaneSketch Plane, Pro|ENGINEER will automatically select the FRONTFRONTFRONTFRONT Datum Plane as the Sketch OrientationSketch OrientationSketch OrientationSketch Orientation Plane.


271. From the Sketcher Toolbar select Sketch Sketch Sketch Sketch

PalettePalettePalettePalette .

272. In the Sketch Palette dialog scroll down and double-left-click the square.

273. To initially place the square left-click any where in the graphics window.

274. Left-click in the Sketcher Palette.




275. In the graphis window left-click-drag the small circle at the centre of the square over the intersection of the two sketch reference lines.

276. To increase the size of the square left-click-drag the black arrow in the bottom right-hand corner (shown larger in the illustration).

277. To finsih sizing middle-click.

278. Double-left-click the dimension and change it’s value to 10,00010,00010,00010,000 (10metres).

279. From the Top Toolbar select Refit Refit Refit Refit

ObjectObjectObjectObject

280. The Sketch is now complete, left-click Accept SketchAccept SketchAccept SketchAccept Sketch .

281. From the Feature Toolbar select Extrude Extrude Extrude Extrude

FeatureFeatureFeatureFeature . Extrude the rectangle 250mm250mm250mm250mm below the Datum Plane.

282. You may wish to change the colour of the model to green.

To give the terrain a more realistic appearance the top face of the solid will be modified.

283. From the Top Toolbar select InsertInsertInsertInsert and from the menu select WarpWarpWarpWarp .

284. Pro|ENGINEER will prompt you to: Select the newly created solid.

285. Pro|ENGINEER will now prompt you to :

286. Right-click and from the menu that appears select Direction CollectorDirection CollectorDirection CollectorDirection Collector. In the Model Tree




select the TOPTOPTOPTOP Datum Plane.

287. Pro|ENGINEER will change the visibility of the model, activate the Dashboard and

prompt you to: . Select SculptSculptSculptSculpt .

288. In the Dashboard select Apply to one sideApply to one sideApply to one sideApply to one side .

289. Change the number of RowsRowsRowsRows and ColumnsColumnsColumnsColumns to 15151515. This relates to what is called the ‘marquee’. You will see a network displayed with ‘nodes’ at the intersections.

290. To Warp the solid left-click-drag these nodes until you’ve created a pleasing terrain. Select AcceptAcceptAcceptAccept to finish and exit the Warp Feature

291. To create the launch pad create a new SketchSketchSketchSketch on the TOPTOPTOPTOP Datum Plane.

292. Sketch a CircleCircleCircleCircle 200mm200mm200mm200mm diamter at the intersection of the two defualt reference lines.

293. ExtrudeExtrudeExtrudeExtrude this circle 50mm50mm50mm50mm above the Datum Plane.

294. To help differentiate this feature from the surrounding terrain; from the Top Toolbar select View and from the menu that appears select

.

295. In the Appearnace EditorAppearnace EditorAppearnace EditorAppearnace Editor change the AssignmentAssignmentAssignmentAssignment critera to SurfacesSurfacesSurfacesSurfaces.

296. In the graphics window select the faces that make up the small cylindrical launch pad, (hold down the Ctrl Key for multiple select) and

select followed by .




297. The Launch Pad is now complete, save the part.

As an additional exercise you may wish to add some buildings to the launch pad area

Task 24: Now for a bit of Rocket Science

One of the most important aspects in Rocket Engineering is MassMassMassMass.

Question: What is MassWhat is MassWhat is MassWhat is Mass?

Answer: Mass is the property of an object that causes it to have weight in a gravitational field. What this means is that an object can have mass but its weight is dependant on the force of gravity. In space while an object still has the same Mass it has no weight as there is no gravity.

Rocket Scientists and Engineers work hard to design rockets with the correct strength to weight ratio, i.e. to be strong enough for the mission but light enough to fly efficiently.

During this tutorial each component has been created as a Solid Model; that means Pro|ENGINEER treats each component as a real, virtual, object that has volume. During the modelling section of this tutorial you should also have been assigning different materials to each component you’ve modelled. Each of the materials has a different density.

The Mass of an object is calculated by the following equation:

Mass = Density x Volume Mass = Density x Volume Mass = Density x Volume Mass = Density x Volume

From the Pro/ENGINEER the top toolbar select AnalysisAnalysisAnalysisAnalysis>ModelModelModelModel>Mass PropertiesMass PropertiesMass PropertiesMass Properties

In the menu that appears select FeatureFeatureFeatureFeature, then click CCCCompute ompute ompute ompute

analysis for previewanalysis for previewanalysis for previewanalysis for preview .




Pro|ENGINEER can calculate the mass of each component and the overall mass of the assembly with the click of a button.

298. From the Top Toolbar select AnalysisAnalysisAnalysisAnalysis and from the menu select ModelModelModelModel and then Mass PropertiesMass PropertiesMass PropertiesMass Properties.

299. In the Mass Properties dialog select FeatureFeatureFeatureFeature for the Type,

the select compute analysis for previewcompute analysis for previewcompute analysis for previewcompute analysis for preview

Pro|ENGINEER immediately calculates the Mass Properties of the Rocket assembly and dispalys the results in the dialog.

Pro|ENGINEER will also create a text file in your Working Directory; the name of the text file is the same as the Pro|ENGINEER file, in this case rocket.m_procket.m_procket.m_procket.m_p.

For Users working in Pro|ENGINEER Schools Advanced Edition you can also create what is referred to as a “measurement feature” within the Model Tree.

300. In the Mass Properties dialog select the Features tab.

301. In the Datums section of the dialogtick PNT_COGPNT_COGPNT_COGPNT_COG, this tells Pro|ENGINEER to create a Point at the Centre Of Gravity within the assembly. To Accept the settings and execute the command select AcceptAcceptAcceptAccept .

Pro|ENGINEER will add the measurement feature to the Model

Tree:




302. To see the C-of-G point toggle on the Datum point DisplayDatum point DisplayDatum point DisplayDatum point Display .

303. Save the assembly.

If you’ve used the dimensions, values and materials specified within this tutorial the rocket massmassmassmass will be around 121212120grams0grams0grams0grams.

NOTE: Mass is NOT weight.NOTE: Mass is NOT weight.NOTE: Mass is NOT weight.NOTE: Mass is NOT weight.

In everyday life Weight is taken to mean the same as Mass. Scientifically however, it is normal to state that the weight of an object is in fact a FORCE.

Question: What is What is What is What is WeightWeightWeightWeight?

Answer: Weight is a Force exerted by a Mass as a result of it’s acceleration under gravity. Weight is measured in NewtonsWeight is measured in NewtonsWeight is measured in NewtonsWeight is measured in Newtons.

When someone asks you your weight and you reply “25kilograms” you are actually telling them your Mass.

F=maF=maF=maF=ma

FFFForce = mmmmass(kg) x aaaacceleration(m/s2)

Acceleration on Earth is taken to be 9.81m/s9.81m/s9.81m/s9.81m/s2222

So for the Rocket:

FFFF = 0.12(kg) x 9.81(m/s2)

FFFF = 1.17 Newtons

So using the scientific meaning of weight, what would the weight of the Rocket be on:-

• The Moon (acceleration due to gravity on the moon is 1.6 m/s2)

• Mars (acceleration due to gravity on the moon is 3.73 m/s2)




Task 24: Ready to Launch

This task requires the use of Pro|ENGINEER Wildfire Schools Advance edition.

A critical part of the engineering process is testing the product to see if it meets it’s design specification / requirements. Some companies build prototypes which are used to test out the product, but this approach is often expensive and for large projects such as rockets simply too expensive.

An alternative to physically testing a product is test it virtuaally, or simulate the test within a computer. Pro|ENGINEER has a number of simulation capabilities from Finite Element Analysis to Dynamic simulation.

In this task Pro|ENGINEER will perform a simulated rockat launch to determine the maximum theoretical altitude the rocket could achieve.

304. From the Pro|ENGINEER top toolbar left-click Create New FileCreate New FileCreate New FileCreate New File . In the dialog box that appears enter “launchlaunchlaunchlaunch”. Make sure the file type is AssemblyAssemblyAssemblyAssembly.

305. Left-click to accept the settings and create the new Pro|ENGINEER assembly.

306. From the Feature Toolbar select Add Component .

307. In the Add ComponentAdd ComponentAdd ComponentAdd Component dialog double-left-click the launch_padlaunch_padlaunch_padlaunch_pad.prt.prt.prt.prt.


308. In the Dashboard left-click over AutomaticAutomaticAutomaticAutomatic and select .

This will position the launch_pad part in the DefaultDefaultDefaultDefault location, where the X0Y0Z0 of the




part is positioned on the X0Y0Z0 of the assembly.

309. To accept this assembly location left-click at the right-hand side of the Dashboard.

The next step is to add the model rocket

310. From the Feature Toolbar select Add Component .

311. In the Add ComponentAdd ComponentAdd ComponentAdd Component dialog double-left-click the rocket.asmrocket.asmrocket.asmrocket.asm.

Pro|ENGINEER will preview the part and prompt: As the launch pad is very large in comparison to the rocket it may be difficult to see the rocket. Zoom into the assembly until you can see the rocket.

Pan / Drag

312. Using the Ctrl and Alt keys and the mouse buttons; move the rocket into the general area of the actual launch pad.

313. Turn on the display of Datum ADatum ADatum ADatum Axesxesxesxes Spin

314. Select the Axis of the rocket (XXXX1111) and the Axis of the launch Pad (XXXX2222).

Pro|ENGINEER will automatically assume an AlignAlignAlignAlign constraint. While this is a correct constraint for basic assemblies the launch simulation needs to create a ‘Mechanism’ constraint.

315. In the Dashboard left-click Convert to Mechanism Convert to Mechanism Convert to Mechanism Convert to Mechanism

ConnectionConnectionConnectionConnection ,

Pro|ENGINEER will create a Cylinder connection. This type of connection will allow the rocket to slide along and around the selected axes.

The next step is to define the ‘translation’ along the axis, that is where along the Cylinder Axis should the rocket be located.

316. Turn on the display of Datum PlanesDatum PlanesDatum PlanesDatum Planes




317. In the Dashboard select PlacementPlacementPlacementPlacement.

318. In the menu that appears select Translation Translation Translation Translation AxisAxisAxisAxis.

319. Left click Select comSelect comSelect comSelect component zero referenceponent zero referenceponent zero referenceponent zero reference (aaaa) and in the graphics window select the ASM_TOPASM_TOPASM_TOPASM_TOP Datum Plane of the ROCKET_ASMROCKET_ASMROCKET_ASMROCKET_ASM....

320. Next left-click Select assembly zero referenceSelect assembly zero referenceSelect assembly zero referenceSelect assembly zero reference (bbbb) and in the graphics window select the top face of the launch pad.

321. In the dialog change the CurrCurrCurrCurrent Positionent Positionent Positionent Position to

0.00.00.00.0, and left-click to select this value as the Regen valueRegen valueRegen valueRegen value.

322. Tick Enable regeneration vauleEnable regeneration vauleEnable regeneration vauleEnable regeneration vaule

323. Tick Minimum LimitMinimum LimitMinimum LimitMinimum Limit. Enter 0.0 for the value. ImportantImportantImportantImportant: the default value is 10000, so you MUST enter 0.0.

324. To complete the assembly process left-click AcceptAcceptAcceptAccept .

325. From the Top Toolbar select Drag Packaged Drag Packaged Drag Packaged Drag Packaged

Components Components Components Components .

326. In the DragDragDragDrag dialog left-click SnapshotsSnapshotsSnapshotsSnapshots to expand the dialog.




327. In the Current Snapshot section left-click the cameracameracameracamera . This will take a ‘snapshot’ of the current position/settings

of the rocket. Left-click to exit the snapshot operation.

This will allow you to quickly return to this assembly/mechanism.

328. Turn off the display of both Datum Planes and Datum

Axes

329. From the Top Toolbar select Saved View listSaved View listSaved View listSaved View list and select FRONTFRONTFRONTFRONT.

330. Save the file, .

Task 25: Simulated Launch

To simulate the launch Pro|ENGINEER will use the ‘Mechanism Design Option’. This functionality is not available in Pro|ENGINEER Schools Edition.

331. From the Top Toolbar select ApplicationsApplicationsApplicationsApplications and in the menu that appears select MechanismMechanismMechanismMechanism.

The Pro|ENGINEER User Interface will change to display the Mechanism Toolbar and Tree. You will also notice the appearance of arrows on the rocket model; these arrows represent the predefined force/thrust of the rocket motor and the mechanism connection.




The next step is to define Gravity and the direction in which it is acting.

332. From the Mechanism Toolbar select Define Define Define Define

GravityGravityGravityGravity .

Pro|ENGINEER will display a large graphic arrow indicating the direction of Gravity and open up the Define Gravity dialog.

If the arrow direction is NOT pointing in the required direction change the Direction values in the Dialog.

Notice that the Magnitude setting for Gravity is 9806.65 9806.65 9806.65 9806.65 mm/sec^2mm/sec^2mm/sec^2mm/sec^2.

Note: Gravity is usually shown as 9.81m/sec^2, this is a rounded-up figure, a more accurate value is 9.80665m/sec^2.

333. To accept the Gravity settings left-click .

The next step is to set the Initial Condition, i.e. define the position from which the simulation/analysis is to start.

334. In the Mechanism Tree right-click INITIAL CONDITIONSINITIAL CONDITIONSINITIAL CONDITIONSINITIAL CONDITIONS and left-click NewNewNewNew.

335. In the Initial Conditions DefinitionInitial Conditions DefinitionInitial Conditions DefinitionInitial Conditions Definition dialog left-click Current Screen and select Snapshot1Snapshot1Snapshot1Snapshot1.





The next step is to set up the ‘analysis run’ for the launch.

337. From the Mechanism Toolbar select

Define AnalysisDefine AnalysisDefine AnalysisDefine Analysis .

338. In the Analysis Definition dialog change:

• TypeTypeTypeType to DynamicDynamicDynamicDynamic

• DurationDurationDurationDuration to 15151515

• Select I.C. StateI.C. StateI.C. StateI.C. State

339. Next select the Ext LoadsExt LoadsExt LoadsExt Loads tab and in the new dialog tick Enable GravityEnable GravityEnable GravityEnable Gravity.

This is CRITICAL, if you forget to enable gravity your analysis will be incorrect.


Pro|ENGINEER can also produce graphs to help interpret analysis results, for example altitude over time, or acceleration, etc.

341. From the Mechanism Toolbar select Generate measure reGenerate measure reGenerate measure reGenerate measure reuslts of uslts of uslts of uslts of

analysisanalysisanalysisanalysis .

342. In the Measure Result dialog select select select select

Create new measureCreate new measureCreate new measureCreate new measure .




343. In the dialog ensure the TypeTypeTypeType is set to PositionPositionPositionPosition then left-click the Select Point

of Motion Axis and select the tip of the rocket’s nose cone.

344. Select to accept these settings

and then to finish the Measurement defintion.

345. To run the analysis; in the Mechanism browser expand ANALYSESANALYSESANALYSESANALYSES, (left-click the small ++++), and then right-click AnalysisDefinition1 AnalysisDefinition1 AnalysisDefinition1 AnalysisDefinition1 (DYNAMICS)(DYNAMICS)(DYNAMICS)(DYNAMICS) and from the pull-down menu select RunRunRunRun.

Pro|ENGINEER launch the rocket based on the force/thrust of the rocket motor.

346. To review the measurement data created as a result of the launch simulation; from the Analysis toolbar

select Generate MeasureGenerate MeasureGenerate MeasureGenerate Measure , then select measure1measure1measure1measure1 and then in the AnalysisDefintion1AnalysisDefintion1AnalysisDefintion1AnalysisDefintion1 in the Result Set area of the menu.




When you then select the Graph icon

in the top left hand corner of the menu, Pro|ENGINEER will display a graph of the new measurement.

Task 26: Additional Activity Suggestions

You can repeat this launch simulation with the other more powerful motors. Appendix C explains how to model rocket motors and apply the relevant thrust.

The US National Association of Rocketry has an extensive list of Data Sheets for the most popular model rocket motors. Please refer to their web site; http://nar.org/SandT/NARenglist.shtml

You may need to extend the duration of the Analysis from 15 seconds to a long duration, e.g. 25 seconds or more for the more powerful rocket motors.

There is also the option of simulating how high the rocket would fly if you launched from the Moon, Mars or Venus. To do this you will need to change the value of Gravity within

the mechanism application; click the Define Gravity icon and enter the required values.

Now that you’ve completed a number of ‘simulated’ launches why not consider doing a real rocket launch. Starchaser stock a wide range of model rocket kits. For a complete list of model rockets and rocket motors please visit the Starchaser online shop at www.rocketstuff.co.uk




If you purchase one of these kits you could measure and model all the individual components, weigh each component and calculate its density and apply this to you Pro/ENGINEER model. You can then run another simulated launch of this rocket then go out and fly the real model rocket and compare results.

How would you measure the maximum altitude achieve by your real model rocket?




AppendixAppendixAppendixAppendix A A A A

How to create new Materials

A critical part of the Design and Engineering process is to assign material information to the model. Assigning materials changes the physical properties of the model, i.e. material density.

As part of PTC’s D&T programme the pro_standards directory should contain a sample set of materials. Pro|ENGINEER can capture an array of matrerial information including:

• Density

• Poisson’s ratio

• Young’s modulus

• Coefficient of Thermal Expansion

• And many more Structural and Thermal properties.

For the purposes of this tutorial the only material property required is Density.

The following steps explain how to create the materials required for this tutorial.

• From the Pro|ENGINEER Top Toolbar select EditEditEditEdit and from the menu that appears select Setup…Setup…Setup…Setup…

• In the Menu Manager select MaterMaterMaterMaterialialialial

This will open the Materials Menu




• From the Materials toolbar select FileFileFileFile and from the menu that appears select NewNewNewNew....

This will open the Material Definition dialog

• In the Material Defintion dialoog enter the required NameNameNameName for the new material.

• Enter the material Density. Enure the correct Units are Enure the correct Units are Enure the correct Units are Enure the correct Units are selected for the Densityselected for the Densityselected for the Densityselected for the Density.

• To save this material for future

use select .

For this tutorial the following materials are required:

• CardboardCardboardCardboardCardboard

o Density = 8.15e-07

• LDPELDPELDPELDPE, (Low Density PolyEthelene)

o Density = 9.18e-07

• Balsa_woodBalsa_woodBalsa_woodBalsa_wood

o Density =1.76e-07




Appendix BAppendix BAppendix BAppendix B

How to create a new colour

When creating models Pro|ENGINEER assigns a default colour to the part. By default Pro|ENGINEER comes with a sample of colours.

The following steps will explain how to create a new colour.,

• From the Pro|ENGINEER Top Toolbar select ViewViewViewView and

from the pull-down menu select .

Pro|ENGINEER will open the Appearance Editor dialog.

• From the top of the dialog select Material> NewMaterial> NewMaterial> NewMaterial> New

• Give the new colour a name i.e. new_bluenew_bluenew_bluenew_blue.




• In the Properties section of the dialog double-left-

click the ColorColorColorColor . This will open the Color Editor.

• Change the R,G,B (Red, Green, Blue) settings to;

o R = 2.8

o G = 3.1

o B = 255

• Left-click

• To define how the new colour will react to light change the IntensityIntensityIntensityIntensity to 46464646 and the AmbientAmbientAmbientAmbient to 20202020.

• Now double-left-click HighlightHighlightHighlightHighlight

• Change the R,G,B (Red, Green, Blue) settings to;

o R = 13

o G = 178

o B = 253

• Left-click

• To define how the new highlight colour will react to light change the ShineShineShineShine to 10101010 and the IIIIntensityntensityntensityntensity to 100100100100

• To finish creating a new colour select in the main Appearance Editior dialog.

• You can now apply the new material to the model.




Appendix CAppendix CAppendix CAppendix C

How to create the model-rocket motors

Aim:Aim:Aim:Aim:

In this section students will learn how to create a model rocket motor and assign a force to the motor. Part of this activity will require Pro|ENGINEER Wildfire 3.0 Schools Advanced Edition.



o Consolidated basic modelling techniques

� Sketching, Extrude and Revolve features and assemblies

� Create ‘internal’ sketch-based features

o Add Datum Points

o Define a variable force using Mechanisms

o Add a Component Interface for automated assembly of the motor

Task C1: Set Working Directory

The model rocket motors can be:

• Created by the User as an extension exercise to the Starchaser Model Rocket Tutorial

• Created by the Tutor/Trainer/Teacher prior to delivering the Tutorial.

If the rocket motors are to be created by the User as an extension exercise a new folder named “rocket_rocket_rocket_rocket_motorsmotorsmotorsmotors” should be created within the rocketrocketrocketrocket folder.

If the rocket motors are to be created by the Tutor/Trainer/Teacher prior to delivering the tutorial the new “rocket_motorsrocket_motorsrocket_motorsrocket_motors” folder should be created under pro_standards/parts_librarpro_standards/parts_librarpro_standards/parts_librarpro_standards/parts_librariesiesiesies folder. Assuming all students will have access to a centrally accessed pro_standards this will allow all Users to access the model rocket motors.




c1. In the Navigator Window browse to the required folder (for students this should be their rocketrocketrocketrocket folder, for trainers this should be pro_standards/part_libraries).

c2. Right-click the rocket or part_libraries folder and select New FNew FNew FNew Folderolderolderolder, call this folder “rocket_motorsrocket_motorsrocket_motorsrocket_motors”

c3. Right-click the newly created rocket_motorsrocket_motorsrocket_motorsrocket_motors folder and select Set Working Set Working Set Working Set Working DirectoryDirectoryDirectoryDirectory.

Important NoteImportant NoteImportant NoteImportant Note: In order for Pro|ENGINEER to locate the rocket motor the search_path.prosearch_path.prosearch_path.prosearch_path.pro be edited and the rocket_motors folder added.

Task C2: Modelling the Motor Case

The rocket motor case will be created by extruding a circle. In the previous modelling operations used to created Sketch-based features the sketch has been created prior to the feature, i.e. externally from the feature. Pro|ENGINEER also has the ability to create what are called ‘internal’ sketches, this is where the sketch exists within the feature.

The modelling of the rocket motor will use the ‘internal’ sketch method.

c4. Create a new Pro|ENGINEER part with the name “B_MOTOR_CASEB_MOTOR_CASEB_MOTOR_CASEB_MOTOR_CASE”

c5. From the Pro|ENGINEER Feature Toolbar select Extrude FeatureExtrude FeatureExtrude FeatureExtrude Feature .

Pro|ENGINEER will display the Extrude Feature tools and options in the ‘Dashboard’ along the bottom of the Pro|ENGINEER window.

c6. In the Extrude Feature Dashboard left-click the word PlacementPlacementPlacementPlacement, this will open a small Dashboard slide-up panel, select DefineDefineDefineDefine.




Before you start sketching, Pro|ENGINEER needs to know where to place the Sketch and how it is to be oriented. Pro|ENGINEER will issue a prompt along the bottom of the Pro|ENGINEER window asking you to;

Pro|ENGINEER will also display the Sketch dialog which captures the selection of Sketch PlaneSketch PlaneSketch PlaneSketch Plane and SketcSketcSketcSketch h h h OrientationOrientationOrientationOrientation information.

c7. Left-click the TOPTOPTOPTOP Datum Plane.

Pro|ENGINEER will then automatically suggest/select the FRONTFRONTFRONTFRONT datum plane as the ReferenceReferenceReferenceReference Plane to define the Sketch Orientation and Sketch view direction.

c8. To accept these references and enter the Sketcher

select .

Once in the Sketcher, Pro|ENGINEER will orient the view to look directly onto the Sketch

Plane. If this doesn’t happen, in the top toolbar select to reorient the view.

At this point you no longer need to see the Datum Planes.

c9. In the top toolbar select to turn off the display of Datum Planes.

c10. From the Sketcher Toolbar select Create Create Create Create

CircleCircleCircleCircle .

c11. Sketch the circle with it’s centre at the intersection of the two default reference lines

c12. Change the diameter dimension to 18mm18mm18mm18mm.

c13. The Sketch is now complete, To accept and exit the Sketcher, left-click Accept SketchAccept SketchAccept SketchAccept Sketch .




Pro|ENGINEER will automatically preview the extrude using an arbitrary value.

You may wish to re-orient the view;

c14. From the Top Toolbar select Saved View ListSaved View ListSaved View ListSaved View List

and from the pull-down menu select either ISOMETRICISOMETRICISOMETRICISOMETRIC or TRIMETRICTRIMETRICTRIMETRICTRIMETRIC to return to a more suitable view orientation.

c15. In the Dashboard enter a value of 70mm70mm70mm70mm for the extrusion depth

c16. Select the ThinThinThinThin option and set a value of 3mm3mm3mm3mm for the wall thickness. Make sure the offset is inside to give an internal diameter of 12mm.

c17. To complete the feature select Accept FeatureAccept FeatureAccept FeatureAccept Feature from the far right of the Dashboard.

c18. Assign cardboardcardboardcardboardcardboard as the material.

c19. Set the part parameters; DESCRIPTION, MODELLED_BY, and PROJECT.

c20. Save the part; from the top toolbar select Save Save Save Save FFFFileileileile and in the Save dialog

select .

In the Model Tree notice that the Sketch (S2D0001) is located internally to the Extrude 1 featured.




Task C3: Modelling the rocket nozzle

The rocket nozzle is one of the most important parts of a rocket engine/motor. The nozzle helps expand the hot gas into usable upward motion (Thrust).

The nozzle will be created using a Revolve feature, again using the ‘internal’ sketch method.

c21. Create a new Pro|ENGINEER part with the name “BBBB____NOZZLENOZZLENOZZLENOZZLE”

c22. From the Pro|ENGINEER Feature Toolbar select RevolveRevolveRevolveRevolve Feature Feature Feature Feature .

Pro|ENGINEER will display the Revolve Feature tools and options in the ‘Dashboard’ along the bottom of the Pro|ENGINEER window.

c23. In the Revolve Feature Dashboard left-click the word PlacementPlacementPlacementPlacement; this will open a small Dashboard slide-up panel, select DefineDefineDefineDefine.

Pro|ENGINEER will display the Sketch dialog which captures the selection of Sketch PlaneSketch PlaneSketch PlaneSketch Plane and Sketch Sketch Sketch Sketch OrientationOrientationOrientationOrientation information.

c24. Left-click the FRONTFRONTFRONTFRONT Datum Plane.


c25. To accept these references and enter the

Sketcher select .




c26. Sketch the nozzle profile shown on the

right using Create LineCreate LineCreate LineCreate Line .

When creating the XXXX3333-XXXX4444 line segment make sure Pro|ENGINEER displays L1L1L1L1 on XXXX3333-XXXX4444 and XXXX1111-XXXX2222 line segments to ensure they are geometrically constrained to the same length.

After XXXX6666 re-select XXXX1111 to close the profile.

c27. Create a Centreline along the vertical reference line.

c28. Add the dimensions shown on the rigjt and change their values.

c29. To create the dimensions which represent the diameter of the nozzle (12mm & 3mm) first right-click the centreline (XXXX1111) then the sketch line (XXXX2222) and then the centreline once more (XXXX3333), followed by middle-click to place the dimension (XXXX4444).




c30. After adding all the dimensions and changing their values, the Sketch is now complete, To accept and exit the Sketcher, left-click Accept SketchAccept SketchAccept SketchAccept Sketch .

Pro|ENGINEER will preview the revolve.

c31. To complete the feature select Accept Accept Accept Accept FeatureFeatureFeatureFeature from the far right of the Dashboard.

As mentioned throughout this tutorial it is important to assign the correct material to ensure the Mass Property calculations are accurate.

While no pre-defined material exisits for the nozzle material a Density value will be applied instead.

c32. From the Pro|ENGINEER Top Toolbar select EditEditEditEdit and then from the menu select Setup…Setup…Setup…Setup…

c33. In the Menu Manager select Mass PropsMass PropsMass PropsMass Props

c34. In the Setup Mass Properties dialog enter a value of

0.0000020.0000020.0000020.0000025555 for the DensityDensityDensityDensity followed by .

c35. Next set the part parameters, DESCRIPTION, MODELLED_BY and PROJECT.

c36. The Nozzle is now complete, Save the part.

Task C4: Modelling the rocket fuel grain

Model rocket motors employ the same propulsion method as that used by the Space Shuttle’s Solid Rocket Boosters.

Terminology:

• A Rocket MotorMotorMotorMotor typically uses a solid propellant

• A Rocket EngineEngineEngineEngine typically uses liquid propellant




The fuel grain will be created using an Extrude Feature.

c37. Create a new Pro|ENGINEER part with the name “B_B_B_B_PROPPROPPROPPROP” (propellant)

c38. Follow the same process as used to create the B_MOTOR_CASE to create a 15151515mmmmmmmm long Extrusion using a circle 12121212mmmmmmmm diameter. This time do NOT use the Thin option.

c39. Set the Density at 0.0000034

c40. Set the part paramters:

c41. DESCRIPTION, MODELLED_BY, PROJECT

c42. Save the part.

Task C5: Assembling the Rocket Motor

While a rocket motor includes a few more components for the purposes of this tutorial we only need the motor case, nozzle and fuel grain.

The components will be assembled to form the rocket motor.

c43. Create a new Pro|ENGINEER assembly called B_MOTORB_MOTORB_MOTORB_MOTOR

c44. Assemble the B_MOTOR_CASEB_MOTOR_CASEB_MOTOR_CASEB_MOTOR_CASE, B_NOZZLEB_NOZZLEB_NOZZLEB_NOZZLE & B_PROPB_PROPB_PROPB_PROP as shown.

a. First assemble the B_MOTOR_CASEB_MOTOR_CASEB_MOTOR_CASEB_MOTOR_CASE and use the

location.

b. Add B_NOZZLEB_NOZZLEB_NOZZLEB_NOZZLE and assemble it to the B_MOTOR_CASE.

c. Finally add B_PROPB_PROPB_PROPB_PROP




Task C6: Adding a Component Interface

Pro|ENGINEER has the ability to automate the assembly of components using Component Interfaces, these tell Pro|ENGINEER how to assembly components together.

c45. From the Top Tollbar select InsertInsertInsertInsert and from the menu select Model Model Model Model DatumDatumDatumDatum

followed by

Pro|ENGINEER will open the Component Interface dialog and prompt:

c46. Select the outer cylindrical face of the motor_case (XXXX1111) followed by the end face (XXXX2222).

c47. For the end face the required Constraint TypeConstraint TypeConstraint TypeConstraint Type is AlignAlignAlignAlign and the OffsetOffsetOffsetOffset in OffsetOffsetOffsetOffset with a value of 5mm5mm5mm5mm.

Using an offset of 5mm 5mm 5mm 5mm will position the motor so that 5mm will protrude from the base of the rocket making it easier to remove after recovery.

c48. In the Component Interface dialog left-click the default name (INTF001) and change this to MOTORMOTORMOTORMOTOR.

c49. Select to accept these settings.




Task C7: Adding a Datum Point

Pro|ENGINEER has the ability to add Forces to objects, in the case of the rocket motor this will be a point force and will therefore require a point upon which to act.

c50. From the Feature Toolbar select

Create Datum PointCreate Datum PointCreate Datum PointCreate Datum Point .

c51. Change the name of the point to “THRUST_POINTTHRUST_POINTTHRUST_POINTTHRUST_POINT”

c52. Select the Axis

Next, left-click-drag the small white drag handle (circled red), drag it over the end face of the nozzle and then drop it (release the left mouse button) and give it an offset value of 0.0

c53. Select to accept the settings.

c54. At this point save the assembly; from the top toolbar select Save Save Save Save FFFFileileileile and in

the Save dialog select .




Task C8: Defining the Force.

NOTENOTENOTENOTE: THE FOLLOWING OPERATIONS WILL REQUIRE THE USE OF Pro|ENGINEER |ENGINEER |ENGINEER |ENGINEER Wildfire Schools Advanced EditionWildfire Schools Advanced EditionWildfire Schools Advanced EditionWildfire Schools Advanced Edition or University Plus EditionUniversity Plus EditionUniversity Plus EditionUniversity Plus Edition.

Most model rocket motor manufacturers’ have Data Sheets for each rocket motor in their range. These Data Sheets will contain the motor specifications and typical Thrust/Time curve.

The US National Association of Rocketry has an extensive list of Data Sheets for the most popular model rocket motors. Please refer to their web site; http://nar.org/SandT/NARenglist.shtml

c55. From the Pro|ENGINEER Top Toolbar select ApplicationsApplicationsApplicationsApplications and from the menu select MechanismMechanismMechanismMechanism

Pro|ENGINEER will change the menus down the right and left-hand sides of the window.

c56. In the MECHANISM tree, right-click on FORCES/TORQUESFORCES/TORQUESFORCES/TORQUESFORCES/TORQUES and from the menu that appears select NewNewNewNew.




Pro|ENGINEER will prompt

c57. In the Force/Torque Definition dialog:

o Name = “THRUSTTHRUSTTHRUSTTHRUST”

o Type = Point ForcePoint ForcePoint ForcePoint Force

o Left-click Select Point or Vertex and in the Model Tree window select the THRUST_POINTTHRUST_POINTTHRUST_POINTTHRUST_POINT

o Function = TableTableTableTable

� Enter the time Variable and the Magnitude as defined by the motor manufactures’ data sheet.

� Use to add new rows.

o Interpolation = Spline fitSpline fitSpline fitSpline fit

Important Important Important Important Note: Thurst figures will most likely be given Note: Thurst figures will most likely be given Note: Thurst figures will most likely be given Note: Thurst figures will most likely be given NEWTONS (N), NEWTONS (N), NEWTONS (N), NEWTONS (N), when entering values into when entering values into when entering values into when entering values into Pro|ENGINEER multiply by 100multiply by 100multiply by 100multiply by 1000 to convert Newtons into mmkg/sec^2.0 to convert Newtons into mmkg/sec^2.0 to convert Newtons into mmkg/sec^2.0 to convert Newtons into mmkg/sec^2.

c58. Select the Direction Tab

c59. Change the XYZ to ensure the Force direction is acting up along the axis of the motor.

c60. Select and then

.

c61. In the Top Toolbar select ApplicationsApplicationsApplicationsApplications and from the menu that appears select StandardStandardStandardStandard.

c62. The rocket motor is now complete. Save the assembly.

Model Rocket Tutorial

Documents

Transcript of Model Rocket Tutorial