I noticed my pockets were running a little short in the X axis, so today I decided to re-tensioned the X and Y belts, as I could get a finger under them pretty easily. i was having a hard time getting them tight. Then it dawned on me to try a longer screw. So I grabbed a long screw and now my belts are finally tight. I started calculating for belt stretch to make adjustments, but after cutting several circles and square pockets of various sizes I was already within .002" using the the default 40mm per step setting. So I decided that is close enough for what I use the machine for. Next I measured a piece of MDF using calipers, and it was .26". So I set up a test to cut a .26: deep pocket. I think my Z is off by a couple thousandths as well, as I could just feel the edge of my MDF gauge with my fingernail when I put it in te pocket. I have a new Z belt, but I finally have the Dewault trammed and pockets are cutting beautifully, so I decided to leave it for a while while I decide whether or not to convert to a linear Z slider from CMC4NEWBIESon eBay.
Oh yeah, before cutting anything I jogged the machine over to each end to make sure the longer tension screws will not interfere with anything, and it is all good.