Just finished a project which had several shallow cut circles at various diameters. While cutting the grooves the depth would vary at several points and the bit was not cutting into the wood. I adjusted my Z zero to compensate for this thinking that the board was uneven although I had planned it beforehand.
After taking the piece off the machine I checked the thickness of the board and found it to be within .005" TIR. OK, so my spoilboard must be really off. I resurfaced the spoilboard and installed a dial indicator on a 7" long arm and trammed the spindle.
Zeroed the indicator at the right side of the X axis and rotated 180 degrees and found that the X axis is off by .075"
Repeated for the Y axis and it is off by .040"
My question is: Short of using a BFH how does one adjust the spindle to align it.
My machine is a Desktop about a year old and haven't abused it with fast feed rates and/or deep pass depths