Re: NEW member Suitable conversions?

Hi Marc

I use a Boxford CNC lathe just for kicks ;-}

> As a second question, how good is the accuracy of threading on
> systems with encoders on the spindle or chuck?

Good enough for the majority of day to day thread cutting.

> Clearly it must work, but I still have doubts considering the
> rotational speeds of the work, and the inertia of it, and the tools
> themselves.

On the roughing cuts the thread can look pretty awful with a single point
tool.

> Is it really possible with any accuracy, and can it be
> done in multiple passes and pick up at the correct location?

This is how I do my threads, a few heavy cuts, then a few more light passes to
clean up each flank. On coarse thread pitches, I also add a little bit to the
Z start position on each pass. The start and finish points are always where I
programmed them even when doing 1200+ RPM. - Just use plenty of coolant to
flood the cutting point.

FWIW Whilst a CNC lathe is great for those oddball threads - single and
multistart - I don't think it is as useful as a manual lathe for a model
engineer.

Regards Paul.