The code looks ok to me and here is a backplot of what it does.
The only arcs are the small circles at each corner to make sharp corners. The feedrate seems a little excessive for them at 200 ipm, so unless your machine can move at those speeds, you may want to go into SheetCAM and do some more machine setup. Make sure Mach is setup to rapid at a rate your motors can handle, too. The Z is set to go to 2.5" above zero, but there is a canned cycle for the THC G28.1 that I don't know anything about. It takes control over the Z axis and uses a coordinate setpoint that probably resets zero to the surface of the material at the start. Your pierce time seems to be .3 milliseconds so that points to another setup issue, unless that mystery G28.1 takes care of that, too.
In SheetCAM there is a Mach3 post that will generate code without the THC stuff.
The main feedrate is 60 ipm so that is probably ok, but parts are being done at 200 ipm which might be too fast and cause problems. At first you might want to really slow down the feedrate so you can watch things better, too. 10-20 ipm is a nice speed for small parts like this. You can also use Mach to step through one block at a time to better see what is happening during test runs. Does your display in Mach show the corner arcs properly? If not that might be what is generating your circle. Make sure your settings match for units, too.
Last edited by Rambozo; 10-08-2012 at 01:05 AM.
Long arc, short arc, heliarc and in-the-dark!
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