Thread mill cutter comp problem

[Leif Johnson from MICO Inc]

I have a part that has a 1 1/4-18 & 7/8-18 thread. The minor size on the 7/8-14 is .828. We have been doing it with a 3/4" cutter until we built new fixtures & I reprogrammed it all. When I long handed the code, I would call the cutter comp on a Y- move of .375. Then I would do a 180 degree ramp in. The end result was a tool that didn't move on the callup = good part. But now it seems Mastercam wants to do a 90 degree ramp in and the tool will shift in both X&Y = gouge. Is there a trick to this? I know the cutter is too big, but it is hanging out about 3 inches and they don't want to do it in 2 cuts.

 

Thanks

Leif

[crazy^millman]

Use the helix to make a contour. Then just adjust the start and finish where you need it. I use this all the time to make threads time to a angle or a detail on a part.

 

HTH

[Leif Johnson from MICO Inc]

Thanks. I'll give it a try. I ended up turning the comp to computer to get the job running. My operator was starting to get exited.

 

Leif

[crazy^millman]

Well I was thinking you need to time the start and stop if compwas the problem sohuld have ued wear then you could get the comp to turn on with .0002 of the cut with no poblem and still have the cutter comp work If you dia/rad cutter comp you need a move equal or greater than the rad of the cutter where as with wear you only need a move greater than the amount of comp used. So in theroy you could get within .0002 of an edge turn on cutter comp and cut the part and use .0001 of adjustment and it works like a champ unless it is Fanuc then you need ot do a perpenduclar apporach or some radius move to the cut.

 

HTH

[Leif Johnson from MICO Inc]

It is a Fanuc. We are in the middle of a huge debate on the best way to do things. This is what makes using wear so difficult. For years we have done things a certain way because of machine capability and tooling available. But now we have so many more options, it is making us rethink how we do everything. Our operators dont like change and currently we are using half of the cutters dia for thread milling. If I make a couple of things (wear) different than the norm, I will get calls in the middle of the night because they can't figure out what to do. But, if using wear would be the best way to handle that particular problem, I will change everything to wear.

 

Thanks for your help

Leif