Thread: Power tapping without reversible drill press

I have used these units with 1.5-2HP drill presses, belt drive and geared head. They work well but have some issues, probably the biggest being that the drill needs to have a good dose of low speed torque, ie. fairly powerfull motor and a good range of spindle speeds, with the lowest in the 100-150 RPM range, slower is better. We had a 1.5HP 16 speed belt drive (lowest speed 125) and a 2HP 6 speed gear head unit with a two speed motor, (lowest speed 80RPM). The belt drive had issues with belt slip using the head until we cleaned the pulley set and replaced the supplied belts with decent ones.

The other issue we had is that the tap holder in the chinese unit we had that appears identical to the video was not well hardened and chews out fairly quickly. This is basically two metal flats joined by a captive screw with LH thread one end and RH thread the other. The concept is that they are self centering as the screw is wound in or out to clamp or release the square end on the tap, but the flats are softer than the flats on the tap shank and wear quickly, and are hard to source as replacement parts. We found that the safest way to handle the anti rotation bar was to slip a bit of heavy tube over the bar to extend it, then wrap a bungy around the drill column a few turns, bring the tube up to the bungy, and then wrap a few more turns around the column. The inner layer of bungy protects the column from damage by the tube, and the outer layer holds the tube against the column but allows some flexibility to let the head rise and fall while tapping.

The reversing mechanism works well enough, and the overload clutch system works fairly well, set for a particular tap size and material then forget about it till you need to run a different setup. Overall very good system once you get used to setting it up. We we running 6mm to 12mm taps in mild and 304/316 bar.

I have a brand new made in Japan unit, that has never been used. I might just have to list on Flea bay to get some extra Go kart funds.

Cheers Bruce

Originally Posted by argeng

I have a brand new made in Japan unit, that has never been used. I might just have to list on Flea bay to get some extra Go kart funds.

Cheers Bruce

Hi Bruce, what sort of money will you be hoping to get for it????????? Could be interested.
Regards
Kryn

Hi kryn,
I will did it out to find out the exact details of the unit, model, maker etc.

Regards
Bruce