Losing my mind dealing with Selftest Axis Length, Axis S Error; any ideas?
I'm officially going crazy; I've spent 2 days now trying to figure out the
Selftest error! Please check: Axis length: Axis Length X.
error. I've done every conceivable check.
There are no obstructions on the X axis.
I've used wd-40 on both X rods.
The x-motor is not slipping, (screwed into the flat tooth on the motor shaft), the gear and belt fit perfectly.
There is no tension/hiccups when I manually move the x left & right.
It's aligned perfectly on Z.
X plate on the extruder is tight; wires are snug.
Belt is tensioned at 250. Have tried 230, 260.
The wire harness is not causing any tug on the extruder.
I've ripped apart the extruder and reassembled it. I'm at wits end. This is a new printer; but I absolutely cannot get past this part. I've tried everything. Does anyone have any suggestions? Much appreciated.
RE: Losing my mind dealing with Selftest Axis Length, Axis S Error; any ideas?
You appear to have a Bear extruder
I have never used a bear extruder, on the Prusa Extruder the Fan wires are routed inside the extruder housing, in a slot around the side fan.
also the filament sensor wires are normally tucked away out of sight. and the cable bundle on the rear od the extruder normally has more cable ties. I suspect you need to check that the fan wires, filament sensor wires, and the braided sheath are not touching the frame at either end of the X axis travel
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: Losing my mind dealing with Selftest Axis Length, Axis S Error; any ideas?
Thanks. It's pretty hard to see but cables are not touching on either X-axis end. Is there anything else that you could think about? Thank you. 
RE: Losing my mind dealing with Selftest Axis Length, Axis S Error; any ideas?
resistance to movement on the axis is the next most likely issue
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: Losing my mind dealing with Selftest Axis Length, Axis S Error; any ideas?
Possibly the screws fixing the X-carriage back are too tight and the carriage is squeezing the linear bearings ?.
That happened to me when I assembled my MK3S+ the first time. I had to release carefully those screws a couple of turns, one screw at a time, until the error went away. Now, I notice that if I release or retighten slightly those screws, the value of the X-belt calibration changes a bit.