Odd issue I’ve been having. After cutting a pocket .85in deep, the X-Carve seems to not move accurately on the y-axis and moves farther than it should. After cutting it again with slower feed rates I obtained the same results. I tried a shallow cut on some waste MDF, and everything was dimensionally accurate. At this point, I’m at a lost as the machine seems to work perfectly as long as I don’t cut too deep.
How deep are you cutting per pass? What speed are you cutting at? What size endmill are you using? What speed is the router/spindle set at?
You may be overloading your machine (Y-axis) causing steps to be lost.
Check your belts/pulleys and make sure none of those are slipping.
Your test carve in weaker material at lighter loads indicate something is overloaded when you did your .85" deep pocket.
As Erik suggested, your cut parameters would be nice information too 