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  1. #1
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    387

    Incremental arcs and Break arcs into lines

    I have a thread mill path that I'm playing with. I need to break the arcs into lines for an old controller. The arcs are incremental. I've been able to break arcs that are absolute but the incremental arcs don't break properly. I tried setting the arc centers to absolute without success. Is there a way to convert incremental paths to absolute prior to breaking?

    This is the test code:
    G90 G00 X0 Y0
    G91 G00 X0 Y0 Z-0.379
    G01 G41 D60 X0.0148 Y-0.0802 Z0 F18.59
    G91 G03 X0.0802 Y0.0802 Z0.0038 R0.0802 F18.59
    G91 G03 X0 Y0 Z0.0417 I-0.0950 J0 F61.97
    G91 G03 X-0.0802 Y0.0802 Z0.0038 R0.0802
    G00 G40 X-0.0148 Y-0.0802 Z0
    G90 G00 Z1.0000

  2. #2
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    Oct 2007
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    51

    Coordinates to absolute

    Yes you can convert coordinates to absolute in NcPlot 2.20
    Highlight the code that your editing (select the whole G91 string) then go to Tools\Convert Coordinates to ABS then change that G91 to G90 then you should be able to break arcs into lines. After finishing you can change the code back to incremental
    Highlight the code that your editing (select the whole G90 string) then go to Tools\Convert Coordinates to INC then change that G90 to G91

  3. #3
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    you code may need to be cleaned up first i had to get rid of feed rates and z height save file under different name and open both under file\compare file. Then edit and add back needed feed rates and z height also if your controller doesn’t need redundant G moves (G00,G01,G02,G03) clean them up to

  4. #4
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    Still can't quite get this to work. This is a helix so I can't really strip the z values but the z values are converting to abs fine.

    This is after conversion:
    G90 G00 X0 Y0
    G00 X0 Y0 Z-0.379
    G01 G41 D60 X0.0148 Y-0.0802 Z-0.379 F18.59
    G03 X0.095 Y0 Z-0.3752 R0.0802 F18.59
    G03 X0.095 Y0 Z-0.3335 I-0.0950 J0 F61.97
    G03 X0.0148 Y0.0802 Z-0.3297 R0.0802
    G00 G40 X0 Y0 Z-0.3297
    G90 G00 Z1.0000

    This appears to plot fine but when I convert the arcs to lines it breaks. Clearly I'm missing a step. Do you see anything obvious?

  5. #5
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    Mar 2003
    Posts
    765
    Arggg... sorry about that. I thought I fixed the breaking of helical arcs but there is still something broken. Here is your code (in absolute):

    G00 X0 Y0
    G00 X0 Y0 Z-0.379
    G01 G41 D60 X0.0148 Y-0.0802 Z-0.379 F18.59
    G01F18.59X0.0261Y-0.0794Z-0.3787
    X0.0372Y-0.077Z-0.3783
    X0.0478Y-0.0731Z-0.378
    X0.0577Y-0.0677Z-0.3776
    X0.0669Y-0.061Z-0.3773
    X0.0749Y-0.0531Z-0.3769
    X0.0818Y-0.0441Z-0.3766
    X0.0873Y-0.0342Z-0.3763
    X0.0914Y-0.0236Z-0.3759
    X0.094Y-0.0126Z-0.3756
    X0.095Y-0.0013Z-0.3752
    X0.095Y0Z-0.3752
    G01F61.97X0.0942Y0.0123Z-0.3743
    X0.0918Y0.0244Z-0.3735
    X0.0879Y0.0361Z-0.3726
    X0.0825Y0.0471Z-0.3718
    X0.0757Y0.0574Z-0.3709
    X0.0676Y0.0667Z-0.37
    X0.0584Y0.0749Z-0.3692
    X0.0482Y0.0819Z-0.3683
    X0.0372Y0.0874Z-0.3674
    X0.0256Y0.0915Z-0.3666
    X0.0135Y0.094Z-0.3657
    X0.0013Y0.095Z-0.3649
    X-0.0111Y0.0944Z-0.364
    X-0.0232Y0.0921Z-0.3631
    X-0.0349Y0.0884Z-0.3623
    X-0.046Y0.0831Z-0.3614
    X-0.0564Y0.0764Z-0.3606
    X-0.0658Y0.0685Z-0.3597
    X-0.0741Y0.0594Z-0.3588
    X-0.0812Y0.0493Z-0.358
    X-0.0869Y0.0384Z-0.3571
    X-0.0911Y0.0268Z-0.3562
    X-0.0938Y0.0148Z-0.3554
    X-0.095Y0.0025Z-0.3545
    X-0.0945Y-0.0098Z-0.3537
    X-0.0924Y-0.022Z-0.3528
    X-0.0888Y-0.0337Z-0.3519
    X-0.0837Y-0.0449Z-0.3511
    X-0.0772Y-0.0554Z-0.3502
    X-0.0694Y-0.0649Z-0.3494
    X-0.0604Y-0.0734Z-0.3485
    X-0.0504Y-0.0806Z-0.3476
    X-0.0395Y-0.0864Z-0.3468
    X-0.028Y-0.0908Z-0.3459
    X-0.016Y-0.0936Z-0.345
    X-0.0038Y-0.0949Z-0.3442
    X0.0086Y-0.0946Z-0.3433
    X0.0207Y-0.0927Z-0.3425
    X0.0326Y-0.0892Z-0.3416
    X0.0438Y-0.0843Z-0.3407
    X0.0544Y-0.0779Z-0.3399
    X0.064Y-0.0702Z-0.339
    X0.0726Y-0.0613Z-0.3382
    X0.0799Y-0.0514Z-0.3373
    X0.0859Y-0.0407Z-0.3364
    X0.0904Y-0.0292Z-0.3356
    X0.0934Y-0.0172Z-0.3347
    X0.0949Y-0.005Z-0.3339
    X0.095Y0Z-0.3335
    G01X0.0942Y0.0113Z-0.3332
    X0.0918Y0.0224Z-0.3328
    X0.0879Y0.033Z-0.3325
    X0.0825Y0.0429Z-0.3321
    X0.0758Y0.0521Z-0.3318
    X0.0679Y0.0601Z-0.3314
    X0.0589Y0.067Z-0.3311
    X0.049Y0.0725Z-0.3308
    X0.0384Y0.0766Z-0.3304
    X0.0274Y0.0792Z-0.3301
    X0.0161Y0.0802Z-0.3297
    X0.0148Y0.0802Z-0.3297
    G00 G40 X0 Y0 Z-0.3297
    G00 Z1.0000

    I'll get this fixed ASAP.

    Thanks,
    Scott

  6. #6
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    Quote Originally Posted by MetLHead View Post
    Arggg... sorry about that. I thought I fixed the breaking of helical arcs but there is still something broken. Here is your code (in absolute):
    Thanks Scott! I thought I was doing something wrong.

  7. #7
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    OK, this is fixed now. I just released NCPlot v2.21 which includes your fix plus a few other improvements.

    Thanks,
    Scott

  8. #8
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    Thanks for the fix Scott. Works great.

  9. #9
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    Scott,

    I think there may yet be an issue with the incremental helical arcs. With the code below the arcs are shifted when broken into lines. If I create this routine as absolute the arcs break fine. Something is still weird with the inc arcs.

    This a drill and thread mill routine

    N5 G00 G53 G40 G60 G90 D0 Z+0.0000
    N10 G80
    N15 T1 M06
    N20 G54 X+0.0000 Y+0.0000 M08
    N25 Z+0.039370 D1 S10729 M03
    ; ( PRE-DRILLING )
    N30 G01 Z-0.039370 F42.24
    ; ( DRILLING )
    N35 G01 Z-0.501378 F126.72
    N40 G00 Z+0.0000
    N45 G00 Z-0.462008
    N50 G01 Z-0.748346
    N55 G00 Z+0.0000
    ; ( CONVENTIONAL MILLING )
    N60 G00 Z-0.636102
    N65 G01 G91 G42 G64 X+0.0000 Y+0.116220 F59.14 ; (F8.69)
    N70 G02 X+0.000000 Y-0.272480 I+0.0000 J-0.136240 Z-0.008333
    N75 G02 X+0.0000 Y+0.000000 I+0.0000 J+0.156260 Z-0.055551 ; (F15.15)
    N80 G02 X+0.000000 Y+0.272480 I+0.0000 J+0.136240 Z-0.008333 F147.84 ; (F21.72)
    N85 G00 G40 G60 X+0.000000 Y-0.116220
    N90 G00 G90 Z+0.039370
    N95 G00 G53 G40 G90 D0 Z+0.0000 M95
    N100 M30

  10. #10
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    Mar 2003
    Posts
    765
    The problem here seems to be the comment at the end of the line, or rather the problem is with the way NCPlot updates the block:

    G01; (F15.15)X-0.0158Y0.0008Z-0.0009

    The X,Y,Z,I,J,K values are removed from the block and new values are tacked on to the end of whatever is left. In this case when the semicolon ";" is encountered NCPlot takes this to be the end of the line and so this block is being ignored. If you remove the "; (F15.15)" it will plot correctly. So I think the solution is going to be a change to the way I update these blocks.

    Thanks,
    Scott

  11. #11
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    Quote Originally Posted by MetLHead View Post
    G01; (F15.15)X-0.0158Y0.0008Z-0.0009
    Boy I feel dumb. I looked at the converted code but just couldn't see it. Your right, once I remove the comments it works perfectly. Thanks again.

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