Need Help!- Threading Issue with SL80

[crow36]

Hi guys,

Just wanted to find out if anyone out there has encounter any threading issue in which the pitching at the beginning of the thread will differ with the pitching at the center of the thread. The total length of the thread is about 200mm.

Pitching at the beginning of the threads are normally measured ok but it will slowly differs in a very small amount till the last pitch. The difference normally can be up to 12~15 micron between the start and end of the thread.

I have already check the backlash for the X and Z axis and it seems to be ok.

Appreciate any input at this time.
Thank you

Regards

[HFIBryan]

Generally, I've found that on most machines the pitch can vary similar to what you're describing. I usually find that beginning your threading cycle further away from the starting point (my rule of thumb is pitch x2), you will reduce or eliminate that problem. Hope it helps.

[dcoupar]

You are threading in G97 mode, correct?

[crow36]

@HFIBryan : I have tried by beginning the thread further than usual but still result.

@dcoupar : Threading in G97 at this moment

Not sure if any mechanical adjustment could be made to either the gib on X or Z side thou..Used to be ok when we ran this thread 3months ago with the same program and we even tried it on the other machine and the result was good.

[chucker]

Could the part be slipping in the jaws ?