Suspected Software Problems

[JesseSoda]

Hi, I'm new here.

I'm running Mach3 and the latest version of Sheetcam on a custom CNC plasma tube cutter. I use Google Sketchup for drawings. I have been consistently cutting square tube and recently developed problems on newly sheetcam'd drawings. Two things are happening: When cutting holes in one face of a square tube, the cutting speed (normally 80ipm) ramps up to what looks like well over 200ipm, and therefore does not penetrate the wall. Often times in the same program it will cut an identical hole with no issues, however it consistently screws up the same holes every time you load and run that program.

A second issue occurs when cutting two straight lines around the perimeter of a tube (so as to leave two tabs and keep the tube connected until the program is finished). The z axis jumps up and down as it moves in to hit the limit switch. Once it does home, the cut height starts too high, and dives as the tube rotates, and drags along the surface of the last 3 sides. This quirk is pretty consistent on any drawing with this feature, but only on things I've re-sheetcam'd after the problem began. All other operations home normally and feed at the designated speed.

If this doesn't sound familiar to anyone I'll try to take some video and provide hardware information. I suspect it's Sheetcam issue because all of my old G code works just fine. I haven't changed post processors since this problem began. I'd greatly appreciate any advise or just being pointed in the right direction.

Jesse

Similar Threads:

• Problem- Software problems with Num Flexium+
• Problem- Suspected Software Problems
• G201x problem suspected
• Australia Software Problems
• post/software problems

[awerby]

If you're trying to make 3D cuts in rotating tubes, it sounds like you're really pushing the limits of SheetCAM, which, as the name suggests, is intended for 2D work on sheets of material. I'd check the G-code for any commands starting with "F" - those control the speed the machine's supposed to cut at. If you've specified 80 ipm and it's going at 200, it's either assuming it's out of the cut and making a rapid move (also look for "G00"), or it (or your controller) is going haywire. From your description of the movements the Z axis is making, the latter shouldn't be ruled out.

[JesseSoda]

If you're trying to make 3D cuts in rotating tubes, it sounds like you're really pushing the limits of SheetCAM, which, as the name suggests, is intended for 2D work on sheets of material. I'd check the G-code for any commands starting with "F" - those control the speed the machine's supposed to cut at. If you've specified 80 ipm and it's going at 200, it's either assuming it's out of the cut and making a rapid move (also look for "G00"), or it (or your controller) is going haywire. From your description of the movements the Z axis is making, the latter shouldn't be ruled out.

I have the rotaryplasma plugin and have cut thousands of feet of tube before this problem sprung up so I've been very pleased with the performance of Sheetcam over all. It's probably something I inadvertently changed but I was unsure of where to begin looking for a cause. I'll check out those lines of code and see if I can spot anything wonky. Thanks for the input!