Wednesday, February 4, 2015

Accusize Reversing Tapping Head

To get an order out in today's mail, my wife and I completed an order.  (The neighbor's kid had prior engagements for the day.)  I was pleased that I was able to do pretty muvh everything for this fairly simple order.  The one difficulty was tapping some holes in aluminum.  I typically tap holes by putting the tap in the drill press, and turning the chuck by hand.  (Using the drill press ensures a perfectly square threaded hole.)  This requires considerable downward pressure from the right hand, which still doesn't wan to do this.

The problem is that you can't use the power of the drill press, because the motor doesn't reverse.  I have considered buying a self-reversing tap head, which lets you power down to cut threads, then reverses direction when you release the drill press handle.  Tapamatic is the brand name in this market, and priced accordingly, but there is a Canadian manufacturer named Accusize, which is only abou $300.  Anyone have experience with it?


  1. I had a tapping head that I picked up in some sort of long-forgotten deal. Never used it, as I do my power tapping with the Bridgeport mill, so sold it on eBay. I cried when it brought something like $7.00. Tapmatic tapping heads were bringing $100.00 or more at the time, so I figured on getting at least $50.00. It worked perfectly, too.

    If you have any amount of tapping to do, a tapping machine is worth every penny.

  2. What if there were an easier way to rotate the drill press chuck in either direction?

    Would some sort of crank handle on the pulley work? Maybe a ratchet handle? There are ratcheting box wrenches, could a simple hex adapter be made to go in the chuck and hold the tap? Chucks are threaded, perhaps a threaded insert with a center hex section to hold a secondary chuck for the tap below the drill press chuck?

    As for the right hand issues, could a weight be attached to the press handle to provide downward force during tapping, and removed for back-out? A rope with foot pedal?

  3. I believe there are tapping devices that would work similarly to the drill press, without the motor or the spring loading. Basically a base with a tapholder that slides freely in a tube. Unfortunately I have no idea what such a thing would be called.

  4. First thing I googled, isn't QUITE what I was thinking of, but this should give you the idea:

    Ah! Here you go!
    (Also available on Amazon for about 50% More.)

  5. Consider using a battery powered drill. There are fixtures made to hold drills to simulate a drill press. Those are usually pretty cheap. Check craigslist, maybe. I have done tapping with hand drills. Sometimes I chuck the tap directly in the drill, sometimes I can drive it with a reversed socket, to use the square end for the tap, and drive the socket with the correct fitting hex adapter. In some cases, I can chuck the tap handle in the drill. I think there are tap adaptors for ratchets/sockets/drills, I haven't looked for them.