COMPUTER NUMERIC CONTROL MACHINE

Team Members:James Williams (PM)

Eric BlankenshipShawn GossettGlenn SpillerPat Brokaw

Brian Hagene

Team 24: F09-24-CNCMACHD

FTA: Dr. Haibo Wang

OutlineExecutive Summary James

CNC Diagram James

Machine Subsystems– Mechanical Pat & Brian– Motor Drive Eric– Main Controller Glenn– Pendent Shawn

Cost Breakdown James

Implementation Schedule Brian

Summary Brian

Acknowledgements

Executive SummaryProject Objective• A CNC Machine that can be used not only by manufacturers but also by

small scale hobbyists at costs much less than competitors. • Three forms of communication either through serial port, Ethernet, or

USB jump drive• Controllable through a specially designed hand pendant • Multiple tool heads for different applications including milling, paste

dispensing, and air brushing• Able to move at high speeds with longer working life compared to other

relative machines

Why Needed• Other machines perform only one specific task• Loading different programs by current methods result in longer

machine down times and loss in revenue.

CNC Block Diagram

Mechanical SubsystemBase

Y Axis

X Axis

Z Axis

Mechanical SubsystemBase

Table Specifications:•Table Work Area: 1160 in2

•Maximum Part Weight: +18 lbs•Table Supported by Rail: 0.375 in x 1 in

Y-Axis Rail Design:•Length: 38 in•Weight Supported: 40 lbs•Length and Weight was significant•Guide system selected: Supported railY Axis

Mechanical SubsystemX Axis

Designed Considerations:•5.5 lb cutting force•10 lb tool head•100 lb.in moment due to weight•75 lb.in moment due to cutting force

Design Specifications:•X-Rod Diameter: 1.18 in (30mm)•Rod Spacing: 4 in•Supports 37.8 lbs/rod •Maximum deflection: 0.001 in

System Loads:•26.70 lbs, 15.63 lbs, 22.53 lbs

Alternative Design:•4 Rods with 15.63 lbs/rod •Rod Diameter : 1 in•Cost increases

x

Rod 1: 26.70

Rod 2: 15.63 y

Rod 3: 22.53

Mechanical SubsystemZ Axis

Z-Axis Design Considerations:•Minimize moment about x-axis ballscrew•Guide system selected: Versa rails•Moves tool head closer to center of x-axis

Alternative Design:•2 Guide Rods •Increases moment

Mechanical Subsystem

Ballscrew Drive Specifications:•Lead: 0.2 in/rev•Diameter: 5/8 in•Supports: Ball bearing & Thrust bearing block assembly

Thrust Forces:•Acceleration 28.9 lbs -Static friction and acceleration force•Constant Velocity 18.8 lbs -Only kinetic friction

Mechanical Subsystem

Tool Head Options:•Spindle•Paste dispenser

Motor Drive Assembly

• Purpose: Power Motors to drive ballscrews, providing motion in 3 dimensions

Motor Design Requirements

• Provide a minimum 20oz.in of torque at a speed of 4 in/sec. Required to move each axis.

• Be cable of providing a minimum torque safety factor of 100%.

Motor Specifications

Motor sizes: • 276 oz.in (X-axis & Y-axis) • 166 oz.in (Z-axis)Motor Requirements:• 2.8 amps/phase• Voltage of approx. 48 volts for a torque of

80oz.in at 4in/sec.

Motor Driver Considerations

Requirements:• step and direction inputs to move

motors• Cable of driving motors at a

minimum of 2.8 amps.• Surface mount chips to save

space.

Selected:• Allegro A3986 [micro-stepping

sequencer]

Motor Driver ConsiderationsOther design requirements• Low power dissipation: Mosfet H-Bridge

with very low on resistance. (.050 ohm)• Current sense resistor: very low

resistance (.043 ohms)

• Traces :2 oz vs. 1 oz copper. – To Provide low trace inductance to

reduce high voltage spikes from destroying chips. Provide low power dissipation for motor traces.

• Power Transformer selection: provide power to motors that would fit into small cabinet with minimum stray magnet fields.

• System monitoring and fault identification: fuses and LEDs added to aid trouble shooting and protect circuit

Motor Drive SubsystemMotor Drive Subsystem

Features•Pulse width modulation, MOSFET H-Bridge•Motor size from 2 to 4.7 amps•Optical Isolation for all inputs•Full, Half, 1/4, 1/16 step resolution•Over Current Protection•Over temperature and under voltage protection •Fuse Blown Indicators (3 LED’s)•5 V supply Good LED•Outputs to Controller

• Drive Board Ready Signal• Drive Board Fault Signal• Motor Power Supply Ready Signal

Vbb Ready

Optical Isolation

Step

Direction

Enable

Reset

Micro steppingSequencer

MOSFETH-Bridge

A+

A-

B-

B+

Block Diagram

Motor Driver Board

Logic Inputs From Controller

PFD1, PFD2, SR (jumper selectable Connections to Bipolar

Stepper MotorsX,Y,Z axis

Vm+

Vm-

Motor Power Supply

MS1, MS2

12 V Fuse Blown

-12 V Fuse Blown

24 V Fuse Blown

5 VGOOD

Driver Board Ready

Driver Board Fault

To Controller

LED Indicators

Output Signals

VrefX,Y,Z axis

+5 Vdc

+-12 Vdc

Low Voltage Power Supply

System Monitoring and Fault Identification

24 Vdc To Controller

Main Controller Subsystem

Main Controller Subsystem•Ethernet Microprocessor

• ENC624J600 (Microchip Technology)•Communication Controller

• PIC24FJ256GB110 (Microchip Technology)•Motion Controller

• PIC24HJ256GP610 (Microchip Technology)

PIC24HJ256GP610 PIC24FJ256GB110 ENC624J600

PIC24FJ256GB11024 bit 100 pin micro-processor is used to control the communications for the CNC.Any data that comes into the the Controller board goes thorough the Communication micro controller. Specific requirements:1 – SPI 2 – UART8 – Data Pins16 – Address Pins

Connections to the Com controller:• RS232• Serial• USB to Go• Ethernet• VGA(Output)

Features PIC24FJ256GB110Operating Frequency DC - 32MHzProgram Memory(Bytes) 256KProgram Memory(Instructions) 87,552Data Memory(Bytes) 16,384Interrupt Sources 66I/0 Ports A, B, C, D, E, F, GTotal I/O Pins 83Remappable Pins 44

------------------------52

Input Capture Channels gOutput Compare/PWM Channels gInput Change Notification Interrupt 81

-------------------------433

Parallel Communications YesJTAG Boundary Scan/Programming Yes10-Bit Analog-to-Digital Module 16Analog Comparators 3CTMU Interface YesResets POR,BOR,Reset instInstruction Set 76 base instPackages 100-pin

Serial Communications: UART SPI IC

Timers: Total Number (16-bit) 32-Bit (from paired 16-bit timers)

ENC624J60064 pin micro-controller specifically for Ethernet implementation.

No programming was needed for this chip. It comes pre-configured to take Ethernet data. This micro chip connects directly to the Com Controller

Specific Requirements:

1 – SPI

External Connections:

• RJ45 Connector

Features ENC624J600Pin Count 64Ethernet Operating speed 10/11 MbpsEthernet Duplex Modes Half and FullEthernet Flow Control Pause and BackpressureBuffer Memory 24KInternal Interrupt Sources 11Serial Host Interface(SPI) YesParallel Host Interface 8Cryptographic Security Options YesReceive Filter Options Accept or Reject packests with CRCPackages 61-pin TQfP

PIC24HJ256GP61024 bit micro-controller used to take the data from the communication micro chip and distribute Data to the motor driver board.

Specific Requirements:

2 – SPI (to communication)1 – UART (to Pendent)8 – Data Input Pins4 – External Interrupts

Features PIC24HJ256GP610Pins 100Flash Memory 256Ram 16DMA Channels 8Timer 16 bit 9input Capture 8Output Compare Std. PWM 8Codec Interface 0ADC 2ADC 32 chUART 2SPI 2IC 2CAN 2I/O Pins(Max) 85

Interconnects from the main controller to the motor driver board.

MAIN CONTROLLER BOARD

PENDENT

8

16

14

12

1015 13 11 9

7

65

43

2

1

MOTORDRIVER BOARD

1

19

17

15

13

11

9

7

5

3

1

19

17

15

13

11

9

7

5

3

J4 J1

X_S

X_D

Y_S

Y_D

Z_S

Z_D

OE

OR

OM1

OM2

X_S – X-STEPX_D – X-DIRY_S – Y-STEPY_D – Y-DIRZ_S – Z-STEPZ_D – Z-DIROE – OUTPUT ENABLEOR – OUTPUT RESETOM1 – OUTPUT MICROSTEPPINGOM2 – OUTPUT MICROSTEPPING

1 – J1 SERIAL PORT: P2 – J2 SERIAL PORT: MC3 – TB6 PIN 3: MC4 – J11 PIN 1: DB5 – TB6 PIN 4: MC6 – J11 PIN 2: DB7 – J4 PARALELL PORT : MC8 – J1 PARALELL PORT : DB9 – TB7 PIN 1: MC10 – J10 PIN 1: DB11 – TB7 PIN 2: MC12 – J10 PIN 2 : DB13 – TB7 PIN 3: MC14 – J9 PIN 1 : DB15 – TB7 PIN 4 : MC16 – J9 PIN 2 : DB

DB- MOTOR DRIVER BOARDMC – MAIN CONTROLLER BOARDP - PENDENT

Pendent Subsystem

Case

X:

Y:

Z:

A:

JOG

-50 50

Screen

Pendent Subsystem

• Requirements– LCD Screen– Four buttons for accessing different function

screens, accepting a command, canceling a command, and switching the axis between y and z on up and down directional buttons

– Four buttons to change direction on x, y, or z axes– Feed pot dial to increase or decrease feed/speed

rates

Pendent Subsystem• Casing

– Upper section will have a width of 5 inches and a length of around 2.5 inches

• Placement for LCD Screen, Function button, Accept Button, Cancel Button, Axis Switch Button, and Feed Pot Override

– Lower section will have a width 3 inches and a length of 3.5 inches

• Placement for X, Y, and Z directional buttons

Pendent Subsystem• System Diagram

– LCD Screen– PIC 24 Microcontroller– DB9 and MAX32

• Receive and transmit information from main controller system to pendant system

– Voltage Regulator• Input of 5 volts to make controlled

output of 3.3 volts

– Feed pot/Potentiometer• Control of feed/speed rate

– Clock chip• Steady, constant flow of information

– Switch buttons

Pendent Subsystem• PCB Layout

– Top Layer• LCD Screen• Top four buttons are function,

accept, cancel, and axis switch• Bottom four buttons are four axis

direction movement– Left and right control x axis– Top and bottom control y or z axes

– Bottom Layer• Remaining Components• Tightly packed to prevent losses• Connector at bottom to attach to

main controller system

Pendent Subsystem• Screens

– Main Screen• Upper left box contains current x, y, z, and

acceleration axes• Lower left box contains circles for limit

switches which will either be red/green to show on/off

• Upper right box contains current adjustment of feed pot ranging from +-50 % of the rated value

• Lower right box displays the current state of the machine which can be jog, idle, or run

– Other Screens• All Sub Screens• Offsets Screens- Home, Park, Work Offset 1,

Work Offset 2• Soft Limits Screens- Upper and Lower• Parameters Screens- Machine Parameters,

TCP/IP Configuration, Communications Port• Flash Drive Screen

X:

Y:

Z:

A:

JOG

-50 50

Costs

Mechanical Total $ 2,406.89

Electrical Total $ 779.76

Grand Total $ 3,186.65

The Mechanical Total comprises of:•Frame•Bolts•Ballscrews•Rods •Shafts

The Electrical Total comprises of:•Circuit Chips•Driver Boards•Controller Boards•Pendent

Implementation Schedule

Step # Step Description Hours

1 Place parts on boards 4

2 Table Assembly 20

3 Gantry Assembly 15

4 Tapping and Drilling 13

5 Electric Box Assembly 8

6 Assemble Systems 4

7 Testing 5

Total Hours 69

Each component requires different time frames to finish each subassembly. The construction is simple once all subassemblies are finished, and the machine can be fully assembled in a 4 hour period with a three man team. The machine is ready for operation after testing is complete.

SummaryLooked at the Machine LayoutWent through the Subsystems and Considerations

– Mechanical– Motor Driver– Main Controller– Pendent

Went over detailed Cost BreakdownLooked at Implementation Schedule

Acknowledgements

Dr. Haibo Wang- Faculty Technical Advisor

Mr. Mark Hopkins- Technician/ Field Engineer for Allegro Micro-devices

Mr. Howard Everton- President of Norva Plastics

Barb Saathoff- Representative from Dytronix

Tim Attig- Mechanical Shop Machinist

Questions ?