An advantage to the Prusa i3 printers is the excellent and thorough assembly documentation. A disadvantage of the Mini is that since it is not shipped as a kit, excellent documentation is minimal. Something locked up my x axis carriage so it would only move about a quarter inch back and forth. In a long chat session, the agent thought something had gotten in and jammed to pulley on the stepper motor. His only help was a few chat comments and pictures which left a lot to be desired since the fix required removing the hot end, fan, extruder and x axis stepper motor.
There are a number of forum descriptions of problems caused by loose set screws in the belt pulley. Before I started, I decided my problem was that a set screw had backed out and was causing the jam. This turned out to be correct. It just fell out when the stepper motor and pulley were removed.
I found the following 13 minute youtube which is awesome. Everything falls into place when you see the video. If you have a Mini, I encourage you to file this away. Don’t be concerned with the number of steps. It is a fairly simple procedure. Watch for the thin square nuts that can fall out of plastic parts. Do a first layer calibration when finished. Following is a text outline of main steps required that I prepared to supplement the video.
My awesome Prusa Mini is now back in operation! I know that several of you have Mini’s and I hope yours works out as well as mine.
Prusa Mini - Adjusting the X-Axis Pulley Walkthrough
note the tightness of the x axis belt - you will need to readjust it when finished
start with z carriage near top
1:30 left end - loosen two front screws, tensioner two screws from end
1:40 hot end fan - 3 screws - two from outside, one from back, remove
2:04 screw from back (between belts to hot end) - lift off hot end from front
2:25 slide both belt ends forward - carriage stays on rods
does a screw secure belts??
2:55 back - remove extruder - 2 screws in column on left
3:21 remove extruder base, one vertical from bottom, four from back
extruder base lifts off
4:06 vertical screw from below x stepper base - x xis rod assembly lifts off
4:40 back of assembly - 2 screws to release stepper and pinion gear
5:55 check allignment of belt pulley
then remove only one set screw at a time for thread locker