So I decided to resurface my bed from heavy use.
Following the resurface, I remeasured the spoilboard height (Calibrated the work surface height) and then zerod the plywood I was going to cut. I know the plywood is 0.49 inches in thickness but the Z height says it is 0.53 and when measured again was 0.56. What could be causing this? The bit is in the collet tight but something isnt adding up. Thoughts? Thanks!
Are you measuring the same spot as the machine? Plywood, like MDF, is not uniform in thickness.
(Ask me how I know. 
)
Yeah I get that from the 0.53 to 0.56 but even running the toolpath I am digging into my spoilboard.
I did have the gear rack start to vibrate loose in a few spots. Litterly the vibrations were backing out the bolts holding the two pieces together. So I had to put it off and tighten and place back. This occurred after the surfacing. Just not sure if this could also be related?
This is very true
Absolutely. Get that sorted out and try again to see if you get consistent results.