LinuxCNC with DevFoamWing

This question is for anyone using DevFoamWing to create GCode to run on LinuxCNC for a foamcutter.

Mine is running pretty well and we've cut a couple of wings but there are a few odd things happening that seem to be coming from DevFoamWing. I say that because things seem to run fine manually when we run the machine manually from LinuxCNC (to check scaling and such) but when we run the GCode from DevFoamWing, it looks right but....

1) It shows the proper dimensions on the AXIS display but it cuts everything 10X the shown size. By that I mean that instead of the shown 20mm, it moves 200mm. When we run by hand from the MDI tab 10mm is 10mm. I have this corrected for now by dividing all my axis scale factors by 10. With a 200 ppr motor and an 11 tpi rod and no gearing at full step I should get 2200.0 scaling but I have to set 220.0. The fact that it now cuts to the correct size does not make me feel good as I shouldn't have to add a 10x divider. Has anyone else seen this using that software?

2) On slopes, it runs a line of GCode, pauses, runs the next, pauses, etc, etc. You can hear and see the motors run, run, run, run instead of just running from one end to the other. You can see it slightly pause each line of GCode in the code display under the axis display. It leaves small lines in the foam every time it pauses like that. When we run it manually from the mdi everything is smooth with all axes running at the same time. I have never had this issue on my laser machine with a slower PC with worse latency.

This foam cutter has been way more challenging than my rotary cutter or laser cutter.

Thanks
Jeff

TB6600 4A 9-42V Stepper Motor Driver and whole stepping right now. I usually get it working right with full step and then switch to microstepping later.

The scales are close except they are a factor of 10 off. I thought at first I might have 8 micro step set but I checked that and it is EXACTLY 10 times off.

It's not the drive stepping and scaling that is wrong because it is correct when we move manually but not when moved by a design file.

My cut bed is 900mm deep x 900mm high x 1500mm long.

Manually: 50mm move moves 50mm

By Cut File: Axis shows 50mm cut but it moves 500mm.

Everything looks right on the screen but it is scaled X 10 when it cuts.

jeffgar2000@gmail.com wrote:

It's not the drive stepping and scaling that is wrong because it is correct when we move manually but not when moved by a design file.

My cut bed is 900mm deep x 900mm high x 1500mm long.

Manually: 50mm move moves 50mm

By Cut File: Axis shows 50mm cut but it moves 500mm.

Everything looks right on the screen but it is scaled X 10 when it cuts.

Can you post the top of the gcode file you are using, say the first 30 lines

G17 G21 G90 G61 G54
(AXIS,XY_Z_POS,0)
(AXIS,UV_Z_POS,500)
(AXIS,GRID,5)
G0 x0 y0 u0 v0
G21
G17
G90
M3
G1U20.0000V39.1297X20.0000Y39.1297F300.0000
G1U21.0072V39.1297X21.0072Y39.1297
G1U22.0144V39.1297X22.0144Y39.1297
G1U23.0215V39.1297X23.0215Y39.1297
G1U24.0287V39.1297X24.0287Y39.1297
G1U25.0359V39.1297X25.0359Y39.1297
G1U26.0431V39.1296X26.0431Y39.1296
G1U27.0503V39.1296X27.0503Y39.1296
G1U28.0575V39.1296X28.0575Y39.1296
G1U29.0646V39.1296X29.0646Y39.1296
G1U30.0718V39.1296X30.0718Y39.1296
G1U31.0790V39.1296X31.0790Y39.1296
G1U32.0862V39.1296X32.0862Y39.1296
G1U33.0934V39.1296X33.0934Y39.1296
G1U34.1006V39.1295X34.1006Y39.1295
G1U35.1077V39.1295X35.1077Y39.1295
G1U36.1149V39.1295X36.1149Y39.1295
G1U37.1221V39.1295X37.1221Y39.1295
G1U38.1293V39.1295X38.1293Y39.1295
G1U39.1365V39.1295X39.1365Y39.1295
G1U40.1437V39.1295X40.1437Y39.1295

It's not the drive stepping and scaling that is wrong because it is correct when we move manually but not when moved by a design file.

Just to be clear do you mean using the MDI like g1 x50 f300 or jogging manually?

Yes sorry. When we run manually from the mdi using something like G0 X40 U40 it moves 40mm. Not close to 40mm, exactly 40mm.

If the Gcode contains a 40mm long element such as a chord, it shows it as 40mm but when we run it, the machine goes 400mm. Not close to 400mm, exactly 400mm.

jeffgar2000@gmail.com wrote:

Yes sorry. When we run manually from the mdi using something like G0 X40 U40 it moves 40mm. Not close to 40mm, exactly 40mm.

If the Gcode contains a 40mm long element such as a chord, it shows it as 40mm but when we run it, the machine goes 400mm. Not close to 400mm, exactly 400mm.

The only thing I can think of if the PP is scaled wrong or the cad is wrong.

Does the gcode look correct ie. have you checked if the distances are correct in the code?

Something seems to be wrong with the way I am generating the GCode from DevFoamWing. It's a super nice app so I probably have something wrong. I took a quick look at the gcode and everything looked OK but I'm certainly lacking when it comes to reading that. I'm going to try coping a line from the GCODE, pasting in the mdi and seeing how it responds. Got to take my boys to scouts after work so it may be tomorrow before I get that run but I will report back then.

I'm sure I have done something dumb. Just not sure what dumb thig to tell others not to do yet.