Heidenhain Post Issue

[MACHINING JIM]

Not sure if I should post this here or in the Post processor forum but I'll start here for now. I had a strange problem occur today while thread milling a hole. Basically the toolpath did not do what was programmed and what Mastercam back plotted. I had programmed it to cut 3x .015" rough passes with a .005" finish pass, but what happened was a .015" first pass and them a huge second pass which actually broke the brand new tool right off due to the fact that the shank tried to pass through the wall of the bore.

After inspection of the code I calculated that the toolpath position was going to overcut by .250 radially. I went back to recheck my program which still showed the correct toolpath and backplot.

I figured something weird must be happening with the post so I called my re seller and recommended we use the Cimco editor backplot feature to try and narrow down the possibility's of what may be causing this. The Cimco software showed the same an incorrect toolpath that occurred on the machine.

 

So whats happening. Thread milling is just basic X Y Z moves nothing out of the ordinary. Why is this not posting correctly? Why did the first pass go flawlessly. Does it have something to do with multipass?

 

I am using a Heidenhain itnc 530 control on a Tos boring mill and running a generic conversational post by CNC software provided by my reseller and am on X7

[crazy^millman]

Sorry, but a question like that will have to go back to them so they can help you address it. More than likely the post is locked up and not much we could help you with. Basic check is pull up a basic 5 axis machine with the generic 5 axis post and see if the output looks correct. If it does that tells you it is the post if you same the same issue here then will have to old school it where you make each pass an operation to eliminate the error you are seeing. If it is an error and sorry think it is not since I have done threadmilling on many different parts with no issue then you need to let your dealer report it back to QC at CNC so they can figure out what is going on.