UCCNC skipping circles

[schmaus]

I have just started using sheetcam again instead of fusion 360 for plasma cutting with UCCNC software and forgot about a problem I was having long ago. when cutting circles it cuts the lead in and skips the circle. I have read about others having this problem and know that I can change the position or type of the lead in and correct it but that is not an acceptable solution to me.
Does anyone know of a solution the does not require cutting the part to find out which circles it skips and correct those? this has not been happening with fusion. It sounds like a tolerance issue but I don't know how to fix it.

[acourtjester]

Here again attaching a pen to the torch to mark paper while running the G-code. This allows you to see what actually happens and what changes help or not. Paper is cheaper than metal, just remember to use a generic post processor with no floating head or Ohmic sensor operations. Start with a DXF file with 2 or 3 circles, simple setup to test.

[schmaus]

I will try the pen and paper setup but I don't know what to adjust.

The problem is very random and never happened when tool pathing with fusion. It also never happened on my Mach 3 with parallel port machine. This machine is using UCCNC and UC100. The threads I have read explain what is happening but no real answer how to fix it permanently. It has to do with UCCNC cutting a tiny arc versus a whole circle.

CNCDRIVE has said in a thread that you should cut circles as 2 halves but that is not practical to draw and I don't think the post for sheetcam has the option to output circles like that.

[adbuch]

CNCDRIVE has said in a thread that you should cut circles as 2 halves but that is not practical to draw and I don't think the post for sheetcam has the option to output circles like that.

You could simply break your circles at 180 degrees apart. The software will then treat as 2 open paths instead of a single closed path.
David

[schmaus]

I think that is going to have to be the fix for now. Thank You
That seems to me to be a cumbersome solution to a problem that should be easy to fix.

[acourtjester]

Ok I reread you original post and you say this is a problem you had before when using SheetCam went away with fusion 360. Now back with using SheetCam, this points to a G-code or post processor problem. Have you contacted Les at SheetCam to see what he thinks? Another question were you using UCCNC software all the time, if so I would have them check your Plasma Profile. I am using UCCNC at this time and had funny bumps in the road and they looked over my Plasma Profile and suggested changing some setting that got me going.
David shows how to do what they suggest but if you are having a lead in problem that may not help. Actually that fix would need to be cut in a no offset so no lead in, as it is not a closed circle/line. Sorry another question what happens when cutting a square?

[beefy]

.

[schmaus]

OK thanks.

It only happens on circles and not all of them. when it does it if I change the lead in to a different type it works.

[robertspark]

http://www.forum.cncdrive.com/viewtopic ... cam#p11627

edit your sheetcam post processor to automatically break circles into quadrants

this has been discussed to death on the forum but CNCdrive are not going to fiddle with the planner as they want to dedicate their time to other things (that is what I got told.... a few times....)

[schmaus]

Thanks. That worked. I was putting the code in the wrong spot the first time I tried it. I assumed it did not work as I read all those threads before I posted but none of them actually confirm it worked.

I was trying to post over there but I cant remember my password and the reset password option is not working. (never sends me the email)

[acourtjester]

here you go Oh and don't remove cookies your password is affected by that and that stops the auto log on