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.
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.
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!