Grbl problems

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Les Newell
Site Admin
Posts: 3660
Joined: Thu May 11, 2006 8:12 pm

Re: Grbl problems

Post by Les Newell »

The attached post may fix it. To install this post, save the attachment to any convenient folder on your computer then run SheetCam and go to Options->machine->post processor. Click on the 'Import post' button. Using the box that appears, navigate to your post and open it. Go back to Options->machine->post processor and make sure your post is selected.
Attachments
GRBL THC with scriber.scpost
(7.88 KiB) Downloaded 134 times
Ernesto
Posts: 20
Joined: Wed Dec 06, 2017 7:25 pm

Re: Grbl problems

Post by Ernesto »

I can't express my gratitude for your assistance here. I'll try it right now. :)
Ernesto
Posts: 20
Joined: Wed Dec 06, 2017 7:25 pm

Re: Grbl problems

Post by Ernesto »

I just double checked and my primary CAD/CAM computer is running the Linux version of sheet cam. Should I be trying this post processor on the computer that's running Sheetcam in Wine or on the one with the Linux installation, or does it even matter?

Thanks again.
Ernesto
Posts: 20
Joined: Wed Dec 06, 2017 7:25 pm

Re: Grbl problems

Post by Ernesto »

I went ahead and imported the post into the Linux install and it works perfectly. I still need to add the M08/09 commands manually but that's easy.

When I load the gcode it produces into bCNC, in the displayed image, the arcs are turned into 3-4 lines with angles, but the little cone that simulates the tool path is making nice curves, and the motors are curving too. I tried changing Plotting Arc Accuracy in bCNC but it had no effect. Just mentioning this in case others notice it. I'm going to install the computer on the table and will report results.
Attachments
2018-05-29-105552_1280x800_scrot.png
2018-05-29-105552_1280x800_scrot.png (204.32 KiB) Viewed 2513 times
2018-05-29-175011_1680x1050_scrot.png
2018-05-29-175011_1680x1050_scrot.png (129.11 KiB) Viewed 2513 times
Ernesto
Posts: 20
Joined: Wed Dec 06, 2017 7:25 pm

Re: Grbl problems

Post by Ernesto »

When I was going through the code to add the THC M09/08 on/off commands and remove the z coords between them, I noticed that there was one line N0190-N0200 that duplicated in the code straight out of the post. Other than that, which grbl seems to ignore anyway, everything works great!

If anyone's curious to see what the gcode-workflow needs to look like for a grbl controlled plasma table with a floating head and a stand alone torch height controller, here's what I came up with. I'll work on writing it into a post processor so it's plug and play.

(Block-name: Header)
(Block-expand: 1)
(Block-enable: 1)
N0010 G20
N0020 F1
N0030 G53 G90 G40
(Block-name: block)
(Block-expand: 1)
(Block-enable: 1)
N0040 G00 X2.5788 Y5.1226
N0050 X2.5788 Y5.1226
N0060 G38.2 z-1.969 F19.685
N0070 G92 Z0.0
N0080 G00 Z0.0591
(Block-name: block)
(Block-expand: 1)
(Block-enable: 1)
N0090 G92 Z0.0
N0100 G00 Z0.2500
(Block-name: block)
(Block-expand: 1)
(Block-enable: 1)
N0110 M03 S1000
N0120 G04 P1.0
N0130 G01 X2.5788 Y5.1226 Z0.1125 F10
N0135 M08
N0140 G02 X2.5591 Y5.0231 I-0.0596 J-0.0398 F30.0
N0150 X2.5591 Y5.0231 I0.0000 J0.0950
N0160 X2.5393 Y5.1226 I0.0398 J0.0596
N0165 M09
N0170 M05
N0180 G00 X2.5393 Y5.1226 Z0.3937
(Block-name: block)
(Block-expand: 1)
(Block-enable: 1)
N0190 X2.7718 Y7.7690
N0210 Z0.2500
N0220 M03 S1000
N0230 G04 P1.0
N0240 G01 X2.7718 Y7.7690 Z0.1125 F10
N0245 M08
N0250 G02 X2.8384 Y7.6611 I-0.0207 J-0.0872 F65.0
N0260 X2.7751 Y7.5448 I-0.2457 J0.0582
N0270 G03 X2.2823 Y6.3362 I1.2833 J-1.2281
N0280 G02 X2.0298 Y6.0861 I-0.2526 J0.0026
N0290 G01 X1.4961 Y6.0861
N0300 G02 X1.2436 Y6.3386 I0.0000 J0.2525
N0310 G01 X1.2436 Y9.1566
N0320 G02 X1.3008 Y9.2437 I0.0950 J0.0000
N0330 G01 X2.1581 Y9.6152
N0340 G02 X2.2576 Y9.6002 I0.0378 J-0.0871
N0350 G01 X2.9042 Y9.0459
N0360 G02 X2.9373 Y8.9784 I-0.0618 J-0.0721
N0370 G01 X2.9374 Y8.9763
N0380 G02 X2.8384 Y7.6611 I-4.1920 J-0.3455
N0390 G01 X2.8384 Y7.6611
N0400 G02 X2.7196 Y7.6169 I-0.0815 J0.0373
N0405 M09
N0410 M05
N0420 G00 X2.7196 Y7.6169 Z0.3937
(Block-name: block)
(Block-expand: 1)
(Block-enable: 1)
N0430 X1.3315 Y10.3490
N0450 G38.2 z-1.969 F19.685
N0460 G92 Z0.0
N0470 G00 Z0.0591
(Block-name: block)
(Block-expand: 1)
(Block-enable: 1)
N0480 G92 Z0.0
N0490 G00 Z0.2500
(Block-name: block)
(Block-expand: 1)
(Block-enable: 1)
N0500 M03 S1000
N0510 G04 P1.0
N0520 G01 X1.3315 Y10.3490 Z0.1125 F10
N0525 M08
N0530 G02 X1.2849 Y10.2312 I-0.0822 J-0.0356 F70.0
N0540 G01 X1.2207 Y10.2034
N0550 G02 X1.2011 Y10.2087 I-0.0065 J0.0149
N0560 G03 X1.0236 Y10.2987 I-0.1775 J-0.1299
N0570 X0.9843 Y10.2848 I-0.0000 J-0.0625
N0580 G02 X0.3936 Y10.2848 I-0.2954 J0.3653
N0590 G03 X0.3543 Y10.2987 I-0.0393 J-0.0486
N0600 X0.1344 Y10.0787 I0.0000 J-0.2200
N0610 G01 X0.1344 Y0.3543
N0620 G03 X0.3543 Y0.1344 I0.2200 J-0.0000
N0630 G01 X1.0236 Y0.1344
N0640 G03 X1.2436 Y0.3543 I0.0000 J0.2200
N0650 G01 X1.2436 Y5.1181
N0660 G02 X1.3386 Y5.2131 I0.0950 J0.0000
N0670 G01 X2.0866 Y5.2131
N0680 G02 X2.1816 Y5.1181 I0.0000 J-0.0950
N0690 G03 X2.8095 Y4.8357 I0.3775 J-0.0000
N0700 G01 X3.0732 Y5.0715
N0710 G03 X3.0804 Y5.0793 I-0.0417 J0.0466
N0720 G02 X3.5683 Y5.4545 I0.9970 J-0.7914
N0730 G03 X3.5683 Y5.5691 I-0.0250 J0.0573
N0740 G02 X3.0846 Y5.9392 I0.5092 J1.1667
N0750 X3.3331 Y7.0000 I0.7769 J0.3775
N0760 G03 X3.4379 Y7.1261 I-0.2309 J0.2986
N0770 X3.8112 Y9.3997 I-3.3367 J1.7153
N0780 X3.7369 Y9.5340 I-0.2175 J-0.0327
N0790 G01 X2.4029 Y10.6774
N0800 G03 X2.3374 Y10.6873 I-0.0407 J-0.0475
N0810 G01 X1.2849 Y10.2312
N0820 G02 X1.1939 Y10.3193 I-0.0015 J0.0896
N0825 M09
N0830 M05
N0840 G00 X1.1939 Y10.3193 Z3.0000
(Block-name: block)
(Block-expand: 1)
(Block-enable: 1)
N0850 X0.0000 Y0.0000 Z3.0000
N0860 X0.0000 Y0.0000 Z0.3937
N0870 X0.0000 Y0.0000 Z0.3937
N0880 M05 M30
Ernesto
Posts: 20
Joined: Wed Dec 06, 2017 7:25 pm

Re: Grbl problems

Post by Ernesto »

It works! The standalone THC even worked right out of the box. I have a little fine tuning to do but will be cutting metal all day tomorrow.

Thanks again for your help!
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Les Newell
Site Admin
Posts: 3660
Joined: Thu May 11, 2006 8:12 pm

Re: Grbl problems

Post by Les Newell »

What are these doing?
(Block-name: block)
(Block-expand: 1)
(Block-enable: 1)
Ernesto
Posts: 20
Joined: Wed Dec 06, 2017 7:25 pm

Re: Grbl problems

Post by Ernesto »

I copied the code out of the terminal in bCNC and I think it puts that in there once it imports it so you can quickly navigate between the different cut paths in the code. Grbl doesn't seem to see or care about it though. I'll have to double check on my CAD/CAM computer after lunch but I don't think it's a Sheetcam thing.

I'm trying to figure out the post processor modification thing. I can see what the code does, just can't figure out where to put things so they show up in the right place in the g-code. What language should I research to figure out the syntax thing? Is it C?
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djreiswig
Posts: 471
Joined: Sat Feb 20, 2016 4:47 am
Location: SE Nebraska

Re: Grbl problems

Post by djreiswig »

The posts are written in Lua.
https://www.lua.org
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Les Newell
Site Admin
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Joined: Thu May 11, 2006 8:12 pm

Re: Grbl problems

Post by Les Newell »

The Linux version of SheetCam is missing the post docs so I have attached a copy.
Attachments
Post Processor.zip
(6.53 KiB) Downloaded 113 times
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