Ellipse converted from CAD to CNC program and coming out jumpy

[BigDog]

I am using AutoCAD 2011. I am taking an ellipse from CAD and converting to DXF and then placing the DXF into a CNC program (Partworks). When the program is run on the CNC router the ellipse is segmented. I have worked with the CNC program and know that the problem is in the CAD or DXF programs. Does any one know if you can change the size of the segments of an ellipse when it is created or if there is something else I can try? Thank you.

[Dadgad]

If you use the PEDIT command you will have lots of different ways to control the definition, lengths and displays of your ellipse.

[BigDog]

PEDIT will not select the ellipse. It said "object selected is not a polyline". This only happens on an ellipse. Circles or arcs come out of the machine nice and smooth. The object has to go through 4 different programs before it can be cut, (DWG to DXF to Partworks to Shopbot). I was working with it and found that the Partworks and Shopbot programs are older than the CAD program that I am using. I have to save the DWG down to DXF 2004 to get it to go into Partworks, that is where I think the problem is coming in.

[eldon]

Just a suggestion to try - set the system variable PELLIPSE to 1. Then when you draw an ellipse, it is already a polyline.

[BigDog]

The problem was the conversion from DWG 2011 to DXF 2004. I put the part in to PDF and then put it into Partworks and it came out of the machine smooth as you would like. I should have known, the CAD program that I am using is newer than the Shopbot program. That is the biggest problem when you have software that is not up to date.

[Dadgad]

Just a suggestion to try - set the system variable PELLIPSE to 1. Then when you draw an ellipse, it is already a polyline.

Nice one there Eldon, never noticed that option before. I would much rather deal with polylines than ellipses.
BigDog glad you got it sorted out.

[Pablo Ferral]

Big Dog,

There are a few different ways of creating polylines from AutoCAD ellipses. I wrote a comparision of them here:
http://cadsetterout.com/autocad-tuto...ipses-to-arcs/

Including exporting to R12 DXF !

Paul