Re: [CAD_CAM_EDM_DRO] Re: Thread milling

Peter Renolds wrote:

>Hi Guys,
>
>Am I missing something? Don't you need full servo control of your
>spindle in order to perform thread milling? My understanding is the
>tool actually runs in a helix. The other thing that stuck me with the
>initial thread and the machine pictured (with limited Z clearence) was
>also the limited torque available from a small spindle - particularly at
>low RPM's - unless geared. I don't have any experience with thread
>milling so I'm interested to learn more from those in the know.
>
>

The tool ORBITS in a very slow helix, but the spindle does NOT need to be
synchronized to the rest of the motion. You are confusing thread
milling with
rigid tapping. And, you don't need much torque for thread milling.

>Jon, you mentioned you perform thread milling - I assume you have a
>servo controlled spindle via EMC?
>
>

No, I do not.

>My experience with CNC threading has been with a Tapmatic threading unit
>that reverses direction when the feed direction changes. Once I got the
>hang of it, it has worked very well - but I still need to be watching it
>to clear chips periodically.
>
>

This is a device that allows the tap itself to synchronize the spindle
to the Z feed.

Jon