Design Project

Design Project

MAK112E Computer Aided Technical DrawingDr C Erdem IMRAK @ 2011 1

8.30 – 9.30 Project work (meeting)

Search in internet, patents and standards aboutbike types, size and design parameters

child’s height and weight rangesmaximum capacity ??the regulations about carrying peoplesafety requirements

Assign a rapporteur

Prepare the meeting minutes

Design Project - Minutes


Design group nameMeeting minutes

Date :Time :Meeting room :Participants :

Subject & decisions1.2. 3.


3. Principles of Dimensioning

This week you will learn dimensioning . The steps to follow are:

Functional & Non-functional Dimensions Principles of Dimensioning Dimension Placement & Conventions Dimension Tolerances Geometric Dimensioning &

Tolerancing Assignment #2



What is dimension ?Dimensions are defined as numerical values

expressed in appropriate units of measure and indicated on a drawing and in other documents.



FUNCTIONAL DIMENSIONS Functional dimensions directly affect the function or

working of a product and may be of the size or location types.

A datum is a reference line on the drawing from which a component is dimensioned. In practice, a datum is any functional surface or axis used for manufacture, inspection, location, or assembly purposes.

NON-FUNCTIONAL DIMENSIONS Non-functional dimensions, NF in Figure, are those

dimensions which are used for production purposes but which do not directly affect the function or working of a product. Non-functional dimensions usually are not inspected.

7MAK112E Computer Aided Technical Drawing

Dr C Erdem IMRAK @ 2011

9MAK112E Computer Aided Technical Drawing




PRINCIPLES OF DIMENSIONING Dimensions are normally expressed in millimeters. Dimensions of less than unity should be preceded by

zero Each dimension should appear only once It should not be repeated on other views. Dimensions relative to a particular feature should be

placed in one view, which shows the relevant features most clearly, rather than spread over several views.



AUTOMATIC DIMENSIONING Some more powerful CADD systems allow dimensions to

be added automatically to a drawing. In a drawing made by hand, there is no necessary or inherent correspondence between the dimensions of the drawn outline and the intended dimensions of the object, which it represents, until a scale has been specified.



Dimensioning Concept CADD software such as AutoCAD provides three basic

types of dimensioning: linear (horizontal, vertical, aligned, rotated, ordinate, baseline and continued), radial and angular.



Dimensioning System Variables The dimensioning system variables control the appearance of

dimensions. You may set these variables on the command line

Variable Value Explanation . Dimasz <2.5> Controls the size of the dimension arrowhead Dimgap <1.5> Sets the distance around the dimension text above

its line Dimexe <2.0> Determines how far to extend the extension line Dimexo <0> Determines how far extension lines offset from origin

point Dimdli <10> Sets the distance between adjacent dimension lines Dimrnd <0> Rounding dimension text value



Arrowheads



Special Characters

Diameter %%C Ø %%C 50 Ø 50

Degree %%D ° 50 %%D 50 ° Plus/minus %%P ± 50 %%P 2 50

± 2



Text Justification

Centered Above Aligned & Centered

Above Outside



Text Fitting

Rounding off Dimensions



DIMENSION TOLERANCES

Tolerance is the total amount that a specific dimension is permitted to vary; it is the difference between the maximum and minimum limits for the dimension. Tolerances can be applied directly to dimensioned features, using limit dimensioning.


Dimensioning in AutoCAD

Before setting dimension style, format Text Style



To set the dimension varialbes

open Dimension Style …

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MAK112E Computer Aided Technical DrawingDr C Erdem IMRAK @ 2011


Move the mouse on the icon barMove right click



Linear

Horizonral / vertical

Aligned

Radial

Diameter

Angular

Parallel

Baseline

Continous

Leader

Dim text

Position edit

Dimension style dialog

box

Geometric

tolerance



Geometric Dimensioning & Tolerancing



Basic Dimensions

Basic dimensions are the theoretical sizes from which limits of size are derived by the application of allowances and tolerances.



Linear Dimensions



Chain Dimensions



Radial Dimensioning



Angular Dimensioning


Example

1st Select icon

2nd Select point

3rd Select point

4th point

here

+


Example



Next Week ;

You will learn multi-view projection. The steps to follow are:

Projections (ISO-E & ISO-A) Multi-view drawings Projection views (Auxiliary, Detailed etc.) Sketching 2-D Geometry Assignment # 3



Assignment # 2 page : 118 Figure : 76 & 77

You will sketch and complete views

Submit the assignment on time Load file into NINOVA

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Assignment Procedure

Open MAK112E-Temp template fileFormat the drawing file (linetype etc)Sketch the front viewComplete the top view and the side viewFill in the title block (name, number, date etc)Save your (i.e. 301001A2.dwg)Load the file into NINOVA

MAK112E Computer Aided Technical Drawing


Design Project

Documents

Transcript of Design Project