Strange tool path problem

[hahn_rossman]

In the 2 1/2 profiling operations in the attached file I have a problem where some of the arcs behave as expected, and others don't...I've poked around some with post processor options but so far I'm stumped.

DSC_0118.JPG (2.83 MiB) Viewed 8306 times

is an image from the display in linuxcnc of the toolpath.
Also attached is the rhino file with all the cam info.
It should look more like

Screenshot 2015-06-30 20.10.41.png (154.24 KiB) Viewed 8306 times

Any help would be great!
Hahn Rossman

[hahn_rossman]

I was thinking about this on the way back from the shop and I suspect that it has to do with th earc being greater than 180 degrees. I modified the post processor under the general tab by adding .1 to the G90 in the box that gets selected by the radio button for absolute mode. So it now reads G90.1 which should allow linuxcnc to understand the i,j,k offsets correctly.
Hahn "fingers crossed for the morning"Rossman

[1384986994]

Is your machine using IJK values? I forget what the default arc format is for linuxCNC.

Also the dark blue color of the toolpath indicates arc-fitting was performed. You could check that too.

[hahn_rossman]

Switching to G90.1 from G90 and setting the circular motion to I,J,K fixed this problem. Linuxcnc cannot use I,J,K with radius. Hope this saves somebody else some time in the future!
Hahn Rossman