Thursday, April 7, 2011

Another Strategy for Tapping With a Drill Press

I mentioned a few days ago a technique for getting exactly square tapped holes using a drill press.  One downside of that approach is that a tap wrench and tap are often substantially longer than the drill bit used to drill the hole.  In many cases, this means that you have to move the table down to have enough room for the tap wrench and tap.  Now you may have to move the workpiece a little so that the tap is exactly aligned with the hole.

I came up with an even simpler method, at least when tapping relatively soft materials such as acetal.  After you drill the hole, replace the drill bit with the tap and turn the chuck by hand while turning the press downward.  (You can use the chuck key to hold the chuck while turning it without the risk that you might loosen the chuck.)  This works well, and solves the problem of the tap and wrench being much longer than the drill.  This gives you the precise squared threads of that other technique, and only requires two hands.  The other technique is a bit clumsy for those of us who, unfortunately, lack three hands.

1 comment:

Rorschach said...

They actually make a tool that chucks up in a drill-press/Vertical mill that allows the tap to move vertically on a spring loaded spline.
http://www.bigkaiser.com/drill-tapper.php