Fix a Loose Drill-Press Chuck
I’ve had trouble with my chuck sometimes coming out of the morse taper of the drill press. I’ve cleaned the surfaces of both the arbor and the socket, but it still comes out. Is there something else I can do?
Mark Schofield, Southbury, CT
First check to see if there are any burrs on the arbor shaft or in the socket. Even a tiny burr can thwart the locking action of the taper. To check, lightly spin the arbor in the socket. A burr in the socket leaves a shiny line on the shaft, and one on the shaft leaves a line in the socket. In either case, use a piece of fine-grit emery cloth to remove the burr. Clean the surface thoroughly to remove the filings.
Then re-seat the arbor into the socket by twisting and pushing it in one motion. This assures that the tapers align correctly. Next, retract the jaws on the chuck and press it onto a hardwood block with significantly more pressure than you would use to drill a hole.
Remove burrs from the arbor. Wrapping the emery cloth around the arbor reduces the chance that you’ll sand a depression into it. For the socket, wrap the emery cloth around a dowel and reach into it. Again, take care to remove any burrs or bumps without damaging the rest of the machined surface.
Twist in. The tapered arbor won’t seat properly in the matched socket unless you turn the chuck as you push it in (left). Some manuals recommend hitting the chuck with a mallet to seat it, but pressing it onto a wooden block (right) does a better job.