Modification of Commercial Hand Tapper

[Shelly142]

Purchased a commercially manufactured Hand Tapper a couple of years ago and overall it is a well-constructed unit. The only complaint was the way the tap was held in the adapters and the way the combined adapter and tap was held in the spindle. Installation of adapter and tap in the spindle went well, the removal was the problem. Every time the machine was used regardless of the size tap used it was a fight to remove the adapter. First the tap slipped out of the adapter and then the adapter would not come out of the spindle without disassembly of the spindle, spring clip and steel detent ball. Occasionally I ended up chasing the ball around on the shop floor. Replaced the slotted set screws with more traditional hex socket set screws with minimal improvement.

The modification I eventually used came about after Tony Foale’s thread on building a Homemade hand thread tapping machine. His use of two Irwin Tap Adapter’s was an excellent solution to the problem. Tap installation was accomplished with simple hand tightening or loosening.

The Spindle was modified to accept a machined adapter with a set screw spring plunger to act as the detent and then drilled and pinned to the spindle.

So far so good.

[metric_taper]

I have this exact same complaint with my Phase II hand tapper. The collets were made very poorly, and most will not fit the tap without filing to correct size.

[Shelly142]

The main issue for me was removal of tap and adapter without a fight. Otherwise I would have been a happy camper from the get go.

[Altair]

Thanks Shelly142! We've added your Hand Tapper Modification to our Tapping and Threading category,
as well as to your builder page: Shelly142's Homemade Tools. Your receipt:

Hand Tapper Modification by Shelly142

tags: tapping, adaptor

[mbsilvia]

This is brilliant. I consider myself to be an outside the box thinker, but I actually almost bought a whole new hand tapper just to get new collets.. Thank you for the simple yet very effective idea!

[Shelly142]

mbsilvia,
You're welcome, happy to share solutions. I will have to admit that this was not entirely my idea. I borrowed and incorporated this idea from Tony Foale’s thread. He was the first (to the best of my knowledge) that utilized the Irwin Tap Adapter's when he built his machine from repurposed parts he already had. Glad to share just the same and so far this modification is working without any problems.
Shelly142