Gibbs or PostHaste not outputting circle properly ?

[apullin]

Hello folks. I am sort of self taught on GibbsCAM, but I am now hitting a small problem. I have a part that has a few round features on it (see attached picture). The orientation is wrong in the picture, of course. We'll be milling it on a 3 axis Haas VMC.

If I import the SLDPRT into Gibbscam, do a "Roughing" operation, select the body, and select a 1/2" tool, it seems to be cutting the right geometry. However, when I apply PostHaste, I get out an NCF file with many, many linear interpolation moves, instead of just a few G2's and G3's around the round features. We actually ran the part (not noticing that at first), and sure enough, the posts come out as a 20-sided polygons, not nice round posts.

There actually are G2's and G3's in the code, but not for any cutting, just for various movements.

What's going wrong?

It seems that if I individually select every edge and do a geometry extraction, and then do my toolpaths based on that, it will actually output G2's and G3's around the posts properly, although we haven't tried running that yet. Do I really need to manually extract every edge?

[mactec54]

Hi apullin

Just do it as a 2D part select the pins body Tool operation & post

[novak_charlie]

you can just select the main surface and use geometry extract and it will give you all of the geometry from the pins. you dont have to select every edge. i hope this helps.

[apullin]

Thanks, novak_charlie's, that seems to work well! This might get a bit complicated for more complex parts (AR15 receiver!).

[GCMAN]

You may want to check your chord height settings. Go to "File", "Preferences", and under display tab change the chord height setting to .0001". Sometimes if the chord height is larger it facets rounds (circular features). Hope this helps.
GC