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Computer Aided Manufacturing ME158 – Spring 2006. Update simple program slide. What are we doing in this class?. Basic understanding of manual programming of CNC tools CAM using MasterCAM software Introduction to the design and structure of automated tools work and how to operate them
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Computer Aided ManufacturingME158 – Spring 2006 Update simple program slide
What are we doing in this class? • Basic understanding of manual programming of CNC tools • CAM using MasterCAM software • Introduction to the design and structure of automated tools work and how to operate them • Two labs in the shop where you will learn to operate our CNC milling machine • When you’re finished with the class you will be able to program and begin machining your own parts.
How do the tools work? Encoder Motor Ball Screw
How do the tools work? Machine tool bed E Motor Ball screw Amplifier Controller Screw pitch * encoder resolution = axis resolution 5mm pitch * 1/10000 counts per rev. = 0.5 micron/count
Videos • http://www.haascnc.com/news_videos.asp • http://www.engr.colostate.edu/~dga/high_speed_video/#Tools_Machinery_Appliances
Machine coordinate systems Right hand coordinate system Z axis aligned with primary spindle Z+ moves tool away from workpiece
Part coordinate systems Programmer chooses origin for part program Machinist sets the origin on the tool Careful choice of origin before programming is important Choose an origin that you can find easily, and one that won’t change from part to part Think about the fixtures that hold the workpiece
Simple Programs – Tree Mill (MILLINGE) N2(9)M03T01$ N3(0)X2.5Y-2.Z0.25$ N4(0)Z0.1$ N5(1)Z-0.25F5.0$ N6(1)X0.5F10.0$ N7(2)X0.Y-1.5I.5J-1.5D0$ N8(1)Y-0.5$ N9(2)X0.5Y0.I.5J-.5D0$ N10(1)X2.5$ N11(2)X3.Y-0.5I2.5J-.5D0$ N12(1)Y-1.5$ N13(2)X2.5Y-2.I2.5J-1.5D0$ N14(1)Z-0.15F5.0$ N15(0)Z0.25$ N16(9)M30$ END
Program Structure (MILLINGE) N0.1(T)SAMPLE PROGRAM N1(9)M08$ N2(9)M03T01$ N3(0)X2.5Y-2.Z0.25$ N4(0)Z0.1$ N5(1)Z-0.25F5.0$ N6(1)X0.5F10.0$ N7(2)X0.Y-1.5I.5J-1.5D0$ N8(1)Y-0.5$ N9(2)X0.5Y0.I.5J-.5D0$ N10(1)X2.5$ N11(2)X3.Y-0.5I2.5J-.5D0$ N12(1)Y-1.5$ N13(2)X2.5Y-2.I2.5J-1.5D0$ N14(1)Z-0.15F5.0$ N15(0)Z0.25$ N16(9)M30$ END • No spaces • All caps • Zeros not Os • $ at the end of every block • No spaces between words • Event types in parentheses • Program name – 8 characters • End statement • Block numbers can have decimal points • Event 9 – miscellaneous commands • Event 0 – rapid move • Event 1 – linear mill • Event 2 – arc • Other event types for subroutines, pockets, frames, scaling, rotating and other features.
Simple Programs – G and M Code % N1 O0000 ( MILLING EXAMPLE 1 ) N2 ( CREATED ON 01-05-05 AT 6:55 AM ) N3G20 N4G0G17G40G80G90 N5G28Z0. N6G28X0.Y0. N7G92X0.Y0.Z0. N8 ( 1/2 FLAT ENDMILL TOOL - 1 DIA. OFF. - 1 LEN. - 1 DIA - .5 ) N9T1M6 N10G0G90S3056M3X2.5Y-2. N11H1Z.25M8 N12Z.1 N13G1Z-.25F5. N14X.5F10. N15G2X0.Y-1.5I0.J.5 N16G1Y-.5 N17G2X.5Y0.I.5J0. N18G1X2.5 N19G2X3.Y-.5I0.J-.5 N20G1Y-1.5 N21G2X2.5Y-2.I-.5J0. N22G1Z-.15F5. N23G0Z.25 N24M5M9 N25G28Z0. N26G28X0.Y0. N27M30 % %
Manual programming • Operator programs every tool move at the controller – reasonable for simple parts. • Operator programs every tool move at PC using text editor. Program is downloaded onto tool
MasterCAM and other software • Geometry is created in CAM program, or created in CAD program and imported into CAM program. • Tool paths and cutting parameters are selected and software generates program for a particular machine tool. Geometry converter (IGES) Post Processor SolidWorks Geometry MasterCAM Mfg. Model Code file
Programming exercise 3 Ignore setup events Use feed rate of 10 ipm Cut at Z=-.1 2 1” EM
Absolute and Incremental Programming • These commands are Modal – meaning that they stay in effect until changed • Positions can be entered as absolute values (with reference to the part origin) • Or incremental values (with reference to the current location)
Videos • http://www.haascnc.com/news_videos.asp • http://www.engr.colostate.edu/~dga/high_speed_video/#Tools_Machinery_Appliances • http://engineering.llnl.gov/lodtm/about_pg2.html • http://video.google.com/videoplay?docid=7790843153265630790&q=milling