Plasma arc's look faceted when cut, not sure why?

**Web Goblin** · 05-03-2016

I had a quick look at the original dxf and it is made from polylines. Most post processors cant understand them and break them down into loads of little lines. That way you get the kind of effect your are getting with it. Curves end up being made from straight lines. This also causes machines to stutter when trying to process the code also prevents them from reaching top cutting speed due to the amount of code they are trying to load and run.
Take your original drawing and then draw over it in cad using lines and arcs only. Then save it as a dxf and post process it again and try the results. Hopefully you will get a nice smooth contour.

**Neale** · 05-03-2016

One more thought - not sure about Aspire as I use VCarve, but in VCarve there is a "convert to curves" tool. Letters seem to be created as a series of line segments but you can use the "convert to curves" tool to, presumably, convert to curves... I have just done a quick trial but the CAM post-processor in VCarve itself seems to give straight line segments in the gcode in either case. However, it might be that the dxf written out is different which might help with a different CAM processor.

**Robin Hewitt** · 05-03-2016

Convert to curves usually means throwing away details of character and font so you are left with a fixed outline. If the outline is too steppy, look to see if there are any parameters you can tweak in the Convert to Curves command.

**JAZZCNC** · 06-03-2016

Sorry been busy but like been said Clearly there are no G2/3 arc moves only G1 so it's the code not machine or Mach3.

Doesn't matter if you convert to Arc's in CAD or CAM if the post can't process them. Often if standard Post can't deal with Arcs there'll be separate post which does.

**Robin Hewitt** · 06-03-2016

Maybe you can sue them for deformation of character?

**JAZZCNC** · 06-03-2016

Originally Posted by Robin Hewitt

Maybe you can sue them for deformation of character?

**magicniner** · 06-03-2016

Originally Posted by Robin Hewitt

Maybe you can sue them for deformation of character?

You sir should be awarded a prize for that one! :D

**marbles** · 07-03-2016

Pleased to report back that after changing the Sheetcam postprocessor from Mach3 plasma with THC and backlash compensation to Mach3 plasma with THC in the Sheetcam options the curve now cuts as a smooth line. Even the 6, 8 10mm holes are better.

Thanks all :)