How does a tapping head work?

Pretty close. On my Procunier the shaft fits in the drill press spindle and a rod against the column keeps the body from spinning.
Inside are two bell shaped steel pieces with a donut shaped friction plate between them. The shaft drives the upper bell , the friction plate drives the tap and the lower bell is coupled to the upper bell by planetary gears that turn it in reverse and at twice the speed of the upper bell
When you push down, the pressure on the tap pushes the friction plate up to be driven by the upper bell. Forward and at the same speed as the drill press.
When you release the pressure, the friction plate spins free and the tap stops turning
When you lift up, the friction plate is pulled down and is driven by the lower bell. Reverse and twice the drill press speed, unscrewing the tap.
Paul K. Dickman
B.B. wrote in message ...

Thanks!

Whatever you do, don't buy one of those Procunier widgets because you'll find yourself tapping twice the number of holes in about 1/3 the usual time, and what's worse, the tap manufacturers lose a customer because you'll never bust any taps any more.
Jim

I am looking at buying one of them there widgets. Are the Procunier widgets superior to the Tapmatic and are there some models that are far superior / inferior to others?

Greetings Al, Tapmatic type tapping heads work differently than the Procunier type. I use both types in my shop. The tapmatics I use have an adjustable clutch so the torque can be set for different size taps. They also self feed a certain amount so that some shallow holes can be a problem. And even though I set a stop on the quill the Tapmatics will thread to slightly different depths. The Procuniers do not self feed. It is easy to hold thread depth to +/- .003". The more pressure you apply the more torque delivered to the tap. This can lead to tap breakage if you're not used to using them. And really only on the small taps. But I've tapped lots and lots of 00-96 threads in aluminum with a 60 year old procunier tapping head. Most of the time I prefer the Procunier head but the tapmatics seem to run a little cooler when run at maximum speed and lots of holes. So the production tapping usually gets the Tapmatic. ERS

Thanks Eric, that's a nice bit of insight. I really do appreciate it.
Al
Eric R Snow wrote:
B.B.

You're Welcome! That's why I read this NG. I get help and once in a while can help someone else. And that sure makes me feel good. ERS
B.B.

Yea, thanks again. That's the way I feel about the group as well.
Al
Eric R Snow wrote:
, B.B.