r_g

That was it. The M3 jumper on the X axis motor was completely missing. Luckily, I'm a hoarder of electro flotsam, so I could find a replacement. The prind is humming along well now. Thanks a lot! r_g

I've searched the forums and run through a lot of calibration. I'm fairly confident that this issue is not related to a mechanical problem because a) I've triple-checked motors, axes, etc to ensure build is correct and belts drive is ok, and b) the problem is exactly repeatable. I've been using a 20x20x3 mm square to optimize the print quality and now get very good results on layer consistency, bed adhesion and infill. However, the object ends up being 20 mm on the y axis and 40 mm on the x axis. Each time it is exactly the same dimension with the parts being almost indistinguishable in quality and dimension between runs. I suspect this is a software setting issue, but I have not been able to figure it out in Cura. I am hoping that some clever person on the forum will be able help. Thanks, r_g