Making a Tapping Head

[lovemesomemachines]

I hope everyone is safe and well during this time. I thought it would be fun to make a reversible tapping head that could be used on a mill or drill press instead of purchasing one. Anyone know of any plans for such? Thank you.

[754]

Do you have 50 hours to spare ? Cut or buy gears ? Can you harden your own parts ? Do you plan on having a adjustable dutch or slip ?

[chipmaker4130]

50 hrs? No way! Gotta be closer to 150 (or 500 if it were me). Those things are pretty involved.

[danlb]

While there are very complex designs I recall seeing a design that simply used a pair of sliding cones on a common shaft. The cones were used as clutches when they pressed against a spindle.

On PM there is a thread where a guy made one that had a clutch that slipped when the tap bottomed, and backed it out when the mill / drill was put in reverse. https://www.practicalmachinist.com/v...6/#post2043576. Post #17 shows the way it was built. 5 hours, according to the poster.

Dan

[lovemesomemachines]

Ok...so much for the fun.

I don't see any plans for this one, even though it's not self reversing, but none-the-less, seemingly nice:
https://www.youtube.com/watch?v=VJFUvC2CI88

[754]

I can tell you how to build a simple sliding one with a key way , you can set it to stop(actually rotate) when it comes off the key.. then once back on key it can he backed off under power.. I use it on taps over 1/2 that my tapper can't handle. And how to make tap holders , usinga round bore that cant slip, easy to make.

[Canus]

If you decide to buy rather than build let me know. I have several Tapmatic units I can let go reasonably.

[Sparky_NY]

I can tell you how to build a simple sliding one with a key way , you can set it to stop(actually rotate) when it comes off the key.. then once back on key it can he backed off under power.. I use it on taps over 1/2 that my tapper can't handle. And how to make tap holders , usinga round bore that cant slip, easy to make.

That sounds somewhat similar to the Hardinge TT tapping heads in operation. The TT taping head is extremely simple and wouldn't be hard to build. The OP might want to look at the design of the TT heads and do something similar. They work well in lathe or mill.

[754]

Does the Tt use sprag rollers or a key way ?

[Doozer]

I just threw 2 of them in the scrap bin.
I never use them.
They are a pain in the azz.
I do love me some power tapping and instant reverse though.
And if you are going to do that, a Bilz collet chuck is not a bad way to go.
But the Bilz hold the taps so well.
I have a TT chuck, never played with it much.

-Doozer

[gellfex]

I have a Procunier tapping head I picked up for $35 at auction decades ago, and honestly I prefer using the reversing feature of my VFD controlled press. The only issue is you must have good clamping. I've been thinking of adding a foot pedal reverser. I also have a reversing Hamilton sensitive DP with the cone drive danlb mentioned. It's fantastic for small work, up to #10 taps in soft or thin material.

Not my unit, honestly don't know why anyone would want a little drill to go slow.

[oxford]

I have a tapmatic tapping head that I have had for years. I have used it 2 times for the same job. First was for around 150 m8 tapped holes through 5/8” thick aluminum, second time was for around 250. This is where tapping heads really shine.

Unless you either have it setup on a dedicated machine, or you have at least 50 holes, or a bunch of holes to do on a machine that doesn’t have reverse they aren’t really worth getting out.

[754]

I would set mine up on mill for 20 holes., takes 5 or 8 minutes.... having torque control , reversing and that extra speed , its worth it...
5/16!threads at like 400 to 600 rpm...

[Sparky_NY]

Does the Tt use sprag rollers or a key way ?

Neither, it sort of resembles a Lovejoy coupling inside, I suppose you could call them keys . There is a spring that keep the "coupling" apart until it enters the work and is driven. When you stop the feed, the tap continues to pull the lower section down towards the work opening the "coupling" and stopping the feed. There is a pawl, much like a ratchet that engages when the spindle is reversed which backs the tap out.

They are quite small which can be a benefit. The hardinge TT uses proprietary collets but a homebrew version could use ER or similar.

[sarge41]

I've got two, a Procunier, that will do 1/4" to 3/4", don't remember the number, and a little Big-Shepard for small stuff. They work great, but I agree with Doozer, more trouble than they are worth.

JH