Cutting Polycarbonate Profiles, Help!

[Gary Campbell]

Keith...
Did you save the file using the "arcs" postP?
Which program did you create the vectors with?

[Kberry]

Gary,

We use Rhino with RhinoCAM and export to the Shopbot. Postprocessor is Shopbot, not the ShopbotGcode.

[Gary Campbell]

Keith...

It is pretty likely that your design uses short line segments instead of arcs for radius vectors.
You may want to export vectors to one of the CAD/CAM apps and post using the "arcs" post. It uses gCode arcs and results in much nicer radius cuts.

[joe]

Keith,

I think Gary is correct. This has been a problem with SB. Circles and curves which are made from short links seldom cut smoothly. Also Polycarbonate shows every defect. I'm cutting letters from this material which is .75" thick using a V bit. It's a test of nerves since it doesn't sand very well.

Joe

[Kberry]

Hey thanks guys,
I tried to create a Gcode file but it was turning off our spindle when I started the file, any suggestions I dont really understand the coding aspect that well.

Also our machine is really new, is there any sort of "breaking in" time, where we need to go back and readjust our motors, track etc?

[Kberry]

Here are some photos of our recent profiles you can clearly see that pattern bump/ridge

[jerry_stanek]

I would try a rough cut with a straight cutter with an offset then the finish cut so you would only be taking off a small amount and putting the bull nose in.