Mosquito / Bondtech Calibration Fail  

Mosquito / Bondtech Calibration Fail

Apparent problem: Cannot calibrate the Z axis. Fails at Z=5mm.

• I get the message "Calibration Failed! Check the axes and run again."

Another problem I've noticed: threaded rods from Z axis stepper motors shift position as the X carriage travels along the Z axis.

• When the X carriage is all the way at the top, the threaded rods are centered in printed parts Z_axis_top_left and Z_axis_top_right
• When the X carriage is all the way at the bottom, the threaded rods are not centered
  • The left rod touches the right side of the circle
  • The right rod is close to the back of the circle

Another problem I've noticed: after calibration fails (Z = 5mm), if I command the X axis to move right(after increasing to a Z of 7mm), the nozzle will eventually crash into the heated build plate (no steel sheet)

• Happens about 1/2 to 3/4 of the way across the X axis

Context:

I started with a i3 Mk2s. Upgraded it to 2.5. Upgraded it to a Bondtech hotend.

Hotend started to jam frequently on multiple filaments. I replaced the hotend with another V6.

• Experienced the same problems.

I became desperate and decided to change out my V6 hotend for a mosquito hot end.

• Seeing as I already have the hardware for Bondtech, I didn't see the logic in purchasing the Bondtech i3Mk2.5s for Mosquito hot end kit from Bondtech.
• Bondtech offers the step files for their parts so I downloaded it and modified it to use square nuts in place of threaded inserts
• I printed my (very slightly) modified version of the Bondtech i3Mk2.5s for Mosquito hot end successfully
  • I assembled my modified bondtech extruder without problem
• I also purchased the i3 Mk2.5 to i3 Mk2.5s kit from Prusa

When I assembled everything, loaded the new firmware and tried to calibrate it. I got the "Calibration Failed! Check the axes and run again" error when trying to calibrate the Z axis.

• This is when I first noticed that the threaded rods for the Z axis were skewing
• This is when I first noticed that the nozzle would touch the build plate if the X axis was commanded to move away from the home position

Still desperate, I figured that the Y axis was out of tune.

• So I purchased the half-bear upgrade.
• Assembled the half-bear upgrade.
• Installed all the components on the half-bear upgrade.
• Updated the firmware.
• Ran the calibration.
  • Failed to calibrate the Z.
  • "Calibration Failed! Check the axes and run again."

I'm at my wit's end. I followed step 12 of the assembly guide to wiggle the Z motor holder ( https://help.prusa3d.com/en/guide/4-z-axis-assembly_90552 ).

I reprinted the motor holders (on my other printer) at 100% fill in PETG.

• Still the same problems.

I disassembled and reassembled the X axis.

I made sure everything was level. The frame, build plate, table, Y axis rods.

Please help.