Hello, I got calibration problem and I lost a part at mid-printing because the carriage were no longer 'free-running' on the rods.
In fact the rubber seals on one carriage were giving a quite high friction and I lost steps on this carriage.
Use real lubricant, not WD40 or equivalent (which is a solvent, not a lubricant).
I think the best lubricant is ordinary bearing grease (lithium based).
I think I shall do a minimum 'pre-flight' check before starting to print, because that sort of problem is quite noticeable when you move the carriage.
