I've had some problems with my Sherline (running EMC 2, and all the A2Z upgrades). Today, I was watching the final passes on a test piece of aluminum, and watched the Z axis decide to take a 1/4" plunge into the piece before I shut off the driver. It took the required .015" Z axis movement, and when the X axis began to move (on the screen only..the X axis never began to move).. the Z axis kept cutting downward, ruining the piece. Almost like it just "hung up", and continued to do what it was doing regardless of what the software was showing. I've had problems like this before that I attributed to motor couplers loosening on the X/Y axis.. now I'm thinking the Z axis has been the culprit, and causing most of the problems by taking deep bites on occasion.
Has this happened to anyone else? I'm tired of pouring cash into this thing, and having to buy new equipment to replace the stuff I paid alot for to begin with just recently. Time to build a new computer? Upgrade from the Sherline stepper drivers?