Looks like Mazak solved our problem. I won't know for sure for a couple of days, but things look good. They had us add a g61.1 at the beginning of the program. From what I understand, it stops to check data? Anybody care to elaborate on this? I know just enough to be dangerous. I'm sure it will help other Mazak users. Anyway, thanks for a great forum. I think I'll start hangin' around here.

Freddy.nc in the NC files folder. I also have a .mov file viewable with quicktime, but its 20 meg. If it can be of some help, let me know where to put it. Thanks, Freddy

We have a simple 2" radius semi circle with 1/8 radii on the top surface. When we machine this on our Mazak VTC30 M+ using a 3/4 ball endmill, the cut starts on the top. It then travels around the 1/8 radii down through the 2" radius. It starts up the other side removing material. It gets to the top of the other side around the 1/8 radius. The cutter then moves over .005 to repeat the process from the opposite side. Only this time it starts down, but moves away from the material. When it gets to the bottom of the 2 " radii, on its way up it starts to cut again. It only cuts on its way up. Mazak applications and Mastercam applications are scratching there heads. We contacted both to try to figure out our problem. Mastercam applications actually wrote the program. So this eliminates us as the problem. This is suppose to be simple stuff, I thought. Anybody have any ideas? Mazak or Mastercam? Post or Communications?