View Full Version : Plasma Divots and bumps...

03-04-2014, 10:24 AM
Anyone here running SheetCam & Mach3 Plasma?

I'm looking for tips to help get rid of divots and bumps caused by the start and end of the cuts on my small table.

Seems mostly the end of the cut that is causing trouble.11994

These are the best I can get it, 10mm perpendicular lead in with no lead out, adding lead out seems to make it worse, I have been asked to add overlap instead of lead-out but it seems sheetcam can't do that.

Web Goblin
03-04-2014, 12:25 PM
This is very common for plasma where the leadin line comes in straight from the centre line of the circle. What you need to do is program your leadin and leadout for that matter as arcs. This way the machine does not have to slow down or stop at the change of direction and this will stop the blow out hole from arc flare as the machine will still be moving and the arc will not need to go hunting for material and become unstable.
I use sheetcam but not for plasma so I dont know how it handles leadin and leadout lines but normally I would draw them in cad first on seperate layers form the inner and outer contours.

Web Goblin
03-04-2014, 01:45 PM
Just had a quick scan of the manual. When you select create new plasma cutting operation what have you set in the leadin and leadout boxes of the basic tab? Have you tried arc or tangent for the leadin and leadout contours?

03-04-2014, 06:06 PM

the best results I have had are with a long lead in perpendicular and no lead out. This leaves a hard sharp pip behind, lead outs seem to leave a divot.

i have also learnt that what I need is called overburn where the arc goes to maybe 370degrees I.e. Over cuts itself, this burns off the pip.

Sheetcam can't do it yet but they are working on it apparently.

at least I know what it is now.