Computer Aided Engineering Applications 3. Advanced Manufacturing 3.5 NC programming 3.6 Automated Manufacturing systems 3.7 Rapid prototyping

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Lawrence Eaton
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1 Computer Aided Engineering Applications 3. Advanced Manufacturing 3.5 NC programming 3.6 Automated Manufacturing systems 3.7 Rapid prototyping Engi Fall 2014

2 3.5 Part programming Structure of an Automated manufacturing system SCADA Data IO Product description PDE CAM software NC CODE MCU Machine Hardware Control Commands

3.5 Part programming A Part program is a sequence of instructions which describe the manufacturing operations to be performed on a work piece, in the form required by a computer controlled

3 3.5 Part programming A Part program is a sequence of instructions which describe the manufacturing operations to be performed on a work piece, in the form required by a computer controlled manufacturing machine. Upon receiving of the part program (NC code), the automated machine executes the instructions in the code line by line. The main program N specifies the sequence number Comments can be given in brackets or after; A typical NC Code

4 3.5 Part programming Some of the main NC codes Setup commands G90/91 Absolute programming/ Incremental programming G70/G71 Inch / Metric format G54..G59 Work Coordinate system (set by probe) G28 Return to Home Linear interpolation vs Rapid traverse G00 X5 Y6 Rapid traverse to point (5,6) (typically 5-20 m/min speeds) G01 X5 Y6 Linear interpolation to point (5, 6). (@ feed rate)

5 3.5 Part programming Miscellaneous commands M03/M04/ M05 spindle on CW/CCW/ off M07/M08/ M09 coolant on mist/flood/ off M02 program end M06 tool change Spindle, Feed and tools S 1000 set spindle 1000 rpm F 1 set feed rate 1 mm/min T01 select tool 01

6 3.5 Part programming Circular interpolation G02 X5 Y5 R5 (move to x5 y5 with radius 5 clockwise) Cutter compensation G 40/41/42 Cutter radius compensation Cancel/ Left/ Right G 43/49 Cutter height compensation/ cancel

7 3.5 Part programming Job setup Work offset G54 Setup Job setup Tool offset tool diameter/ height compensation Tool wear

8 3.5 Part programming Tool offset setup

Thickness =20mm Tool Info Tool # 1 Drill 5 S=1200 F=70 Tool #2 End Mill 20

9 3.5 Part programming Exercise 1 Write part programs for the following tool paths. Thickness =20mm Tool Info Tool # 1 Drill 5 S=1200 F=70 Tool #2 End Mill 20 S=2000 F=400 Assume G54 set at the top face Drill the 4 holes and perform the finishing profile cut Dimensions are Metric Tool Table T1 L15 D5 T2 L15 D20

10 3.5 Part programming Path verification using NC corrector- Limitations (tool setup), work offset setup Cutter length offset

11 3.6 Automated Manufacturing systems Structure of an Automated manufacturing system SCADA Data IO Product description PDE CAM software NC CODE MCU Machine Hardware Control Commands

12 3.6 Automated Manufacturing systems Main components

13 3.6 Automated Manufacturing systems Mechanical Components

14 3.6 Automated Manufacturing systems Mechanical Components Belt Drives

15 3.6 Automated Manufacturing systems Axis configurations X 2 Axis CNC Lathe Z 3 Axis CNC Mill 5 Axis CNC Mill Configurations

3.6 Automated Manufacturing systems Stepper motor drives Open loop Low load applications Initialization with Limit switches Step sequences are used

16 3.6 Automated Manufacturing systems Stepper motor drives Open loop Low load applications Initialization with Limit switches Step sequences are used to control the motors Basic Length Unit (BLU) = Pitch of ball screw Steps per revolution Example: 400 half steps per rev, 4mm Pitch implies a 10 um BLU

3.6 Automated Manufacturing systems Servo motor drives Relays Closed loop PID using quadrature encoders More precise than stepper drives Initialization with Limit

17 3.6 Automated Manufacturing systems Servo motor drives Relays Closed loop PID using quadrature encoders More precise than stepper drives Initialization with Limit switches/ absolute encoders Direction step commands given to PID as reference Basic Length Unit (BLU) = Pitch of ball screw Resolution of encoder ON/OFF relay drivers

18 3.6 Automated Manufacturing systems Machine Control unit NC CODE Read G code Line by Line Interpolate points from current to target Generate Individual axis reference commands (inverse kinematics) To Actuator drivers

Unit Decode NC code Interpolation Axis command generation Stepper

19 3.6 Automated Manufacturing systems Summary USB/LAN Power Module 5V 24V Servo Drives Quadrature decoders NC Code file Machine Control Unit Decode NC code Interpolation Axis command generation Stepper Drives USER I/O Job setup Manual controls Code Edits RS232 Relay Drives

20 3.6 Automated Manufacturing systems Exercise: Identify the axis reference commands and the motor voltage commands for the following lines of GCode. Assume a 24 V relay and stepper with 400 half steps per revolution connected to a 4mm lead ball screw. G01 X0.05 F100 G01 X0.03 F50 M07 Exercise: Identify the main system components involved in designing a 3 axis PCB drilling machine.

21 3.7 Rapid prototyping Rapid prototyping is a group of techniques used to quickly fabricate a scale model of a physical part or assembly using three-dimensional computer aided design (CAD) data. ҩ There are many methods used in RP. The methods are also referred to as additive manufacturing

22 3.7 Rapid prototyping 1.SLA Stereo Lithography apparatus Materials : Resins

23 3.7 Rapid prototyping 2.SLS Selective laser sintering Ά Materials : Metallic powders Polymer powders

24 3.7 Rapid prototyping 3. FDM- Fused deposition modelling MUN: Fortus 400mc Materials : ABS (M30)

25 4. Zcorp printers 3.7 Rapid prototyping Multi-Jet modelling Polyjet modelling Investment casting ᡰҧ

MANUFACTURING PROCESSES

MANUFACTURING PROCESSES - AMEM 201 Lecture 7: CNC MACHINE TOOLS 1 CNC MACHINE TOOLS TERMINOLOGY NC Numerical Control CNC Computer Numerical Control CAD Computer Aided Design CAM Computer Aided Manufacturing