Testing a Drill Press to Ensure Even Cuts and No Runout
To make sure your drill press is pushing through straight, use a dial indicator precision shaft to test it for any wobble. Among a variety of “setup” tests, I measured flatness and front-to-back squareness of each machine’s table. I also checked for runout (wobble) at the chuck by installing a precision shaft and taking readings off of a dial indicator while slowly rotating the spindle. Runout varied from .001" to .011", but that range of deviation from a single axis of rotation didn’t seem to transfer into noticeably smoother holes or out-of-round holes.
To test the full drill capacity of the presses, Chris Marshall drilled 50 holes in a test block to ensure that they came out the same across the block. My battery of drilling tests involved boring 50, 1-1⁄4" - deep holes in white ash with 1-1⁄2"-diameter Freud Forstner bits (a new bit for each machine).
After drilling out the holes, he measured each hole for depth and tested each for smoothness to ensure the drill was making whole, even cuts. I inspected the results for smoothness and consistent cutting depth. Then, I switched to 1-1⁄2" - diameter spade bits and bored another 50 holes 1” deep.
In testing the eight top drill presses, Chris Marshall made 800 test holes and a huge mess in his shop. That provided good feedback about overall vibration and torque. Tough drilling challenges, to be sure. I made a LOT of hamster bedding drilling 800 holes!