Homing error X

What happened?

The Original Prusa MINI/+ displays the message: "Failed to home the extruder in X-axis, make sure there is no obstacle on X-axis".

Error name: Homing error X

Error code: #12304

The error is most likely caused by a bad movement of the print head along the X-axis. 

How to fix it? 

X-axis movement

Make sure there are no obstructions in the path of the X-axis. For example, there might be a piece of filament stuck around the belt, or on a smooth rod, from a previous print.

X-axis belt tension

Check the X-axis belt tension and adjust it, following our dedicated article on belt adjustment.

X-end assembly

Check whether the X-end is fully inserted onto the smooth rods. Look sideways on the X-end into the inspection hole and ensure that the smooth rod is inserted all the way into the plastic part. Repeat this check for the other X-axis smooth rod. 

Ensure that the two screws that secure the X-end are not loose. If they are not flush or below flush with the X-end, they obstruct the full X-axis range of motion, possibly causing the error. 

X-axis motor pulley

The X-axis motor pulley is attached to the X-axis motor shaft. The motor shaft has one flat side. The pulley has two set screws, ensure that one of the two set screws is aligned with the flat part of the motor shaft. Make sure the other set screw is also tightened, not excessively, and that there is a small space between the pulley and the motor. 

Isolated X-axis motor with attached motor pulley. 

To access the X-axis motor pulley, follow these steps: 

1. Loosen the upper M3x25 screw. The inspection-door might come loose, remove it temporarily. 
   

2. Hold the parts with your free hand! Loosen the lower M3x25 screw, and remove the extruder block. 

3.  Loosen the M3x20 screws holding the trapezoid nut. 
   
4. Hold the parts with your free hand! Loosen the M3x30 screws holding the X-axis block. 
   
5. Move the print head and look into the X-axis pulley inspection hole. Stop when you see a change in the inspection hole when one of the two pulley set screws is aligned with the hole. 
6. Compare the set screw position with the flat part of the motor shaft. 
   
7. In case of a loose or misaligned set screw, tighten one set screw against the flat part of the motor shaft, and ensure the second set screw is also reasonably tight. Use a 2.0mm Allen key for this step. 
8. Reassemble the printer, by performing the above steps in reverse.