Fanuc OM problem surfacing in Gibbs

[jlong58]

I am using Gibbs cam to 3d surface on a Johnford VMC with a Fanuc OM controller and am having a problem. I am trying to cut a round tapered hole 1.5 inches deep 3.75 dia. with an 8 degree taper. When I cut the hole instead of looking round, it is coming out faceted. The facets aren't much, but are enough to feel with my fingers. I have two Johnford machines with the same controllers, but they are different model machines, and I have tried it on both with the same results, so I'm pretty sure it is something in my post processor file. The post was not written specifically for these machines, but runs fine on all other applications. Any Ideas?

[theemudracer]

try slowing the feedrate down. If the code is lots of G01 lines the processor might not be able to look ahead far enough to account for future movements. I used to run a dynapath controler, when I was doing a helical circular inturpulation feeding at 175 ipm the round programmed hole would look like a diamond when it was done. Slowed the feed rate down to 150 ipm and it got better.

[dcoupar]

Is GibbsCAM outputting arcs to go around the circle, or line segments?

[ragman]

I would say the problem is in Gibbs. I have seen the same problem at a place where I worked. The posted output was in many small G01's. We changed something with Gibbs which resulted in the output being in G03 and G02 instead, but unfortunately I can't remember just what. Try contacting Gibbs support.

[cadman]

How are you creating the toolpaths? For simple round tapers you should use a swept surface. This way you will always output arcs.

[jlong58]

I am using taper with fillets, as I have a .125 radius at the top. I think I am using swept shape, but will have to look when I get to work tonight