Re: [CAD_CAM_EDM_DRO] Re: Speed of Tapping Head?

Peter Homann wrote:

> Hi Dave,
>
> Thanks for the reply. Surely the 2000rpm is for the input spindle of the
> tapping head? Is the tap turning that fast, or is it geared down by the
> tapping head. I was expecting something like 30- 60 rpm.

Almost all tapping heads are direct drive when going forwards. Many
go to a higher speed when backing out. So, 2000 RPM on the input
means 2000 RPM at the tap. You need heavy flood coolant, high end
taps, and the ability to back up the spindle feed fast when the tap reaches
the desired depth.

I don't recommend tapping at these speeds unless you have a MASSIVE
production job to finish. But, I've used a "CNC" tapping head to tap from
4-40 to 10-32 threads at 660 RPM on my Bridgeport. the material was
aluminum alloy. A CNC tapping head relies on the CNC machine to
control depth and match quill feed to the advancing tap. When the quill
pulls back on the tap, the head switches clutches and reverses the tap at
2X spindle speed.

Other types of tapping heads have leadscrews to match feed to the thread,
and clutches to limit torque on the tap.

Jon