X5 Thread Mill Quirk?

[R. C. Hinds]

I am thread milling an M100 x2 thread in cast aluminum using a Carmex indexable milling cutter, bottom to top. I was hoping to take advantage of the inserts length and pull away from the cut as soon as the top of insert passed the thread top plus one revolution. Using Mcam thread milling, the tool will enter the cut perpendicular, helix up to the defined top of stock then adds a flat circular interpolation move to pull from the cut at 180 degrees from cut entry. In doing so the cutter then damages all the threads still engaged by the cutter. I had to take the extra time to continue the cut until the inserts cleared the last thread. I have done a test and find the flat circular interpolation move is added top to bottom as well.

 

Has anyone else had this problem?

 

Mcam X5,etc.

[Mr. Wizzard]

I can't double check the parameters at this time, but i will try a guess. I think in the toolpath parameters, there is a section for lead in / lead out or something like that. I think you can adjust it so it pulls straight off of the wall and doesn't arc back to center. That should get rid of the move that's ruining your threads. Again, a lot of "thinking", but, sorry, I cannot get to that toolpath right now. Mastercam has been frozen up on a pretty rough surface calculation for the past couple of hours......

[cam-eleon]

Are you using the helical entry/exit at top of thread option? The tool should helix on and off the thread if there is a possibility of the cutting insert still being engaged in the material.

[gcode]

see the screen shot.. this should solve your problem

[R. C. Hinds]

Thanks all

I found that I had defined a multi flute thread mill as a single, once defined with the number of active teeth, I got the faster cycle I was looking for.

With that cycle I used the helical entry/exit and got a good transition between passes.