3.5s+ upgrade, can't get x axis calibration to complete successfully
 
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3.5s+ upgrade, can't get x axis calibration to complete successfully  

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Pete
 Pete
(@pete-6)
Member
3.5s+ upgrade, can't get x axis calibration to complete successfully

I know this problem is posted somewhere else in these forums,  but I'm having the dreaded x axis calibration failure (with no diagnostic message to help) after upgrading my 3s+ to a mk3.5s+, and changing out the pinda for the superpinda. I've literally spent hours on this at this point.   here's what I've checked and tried: 

* verified that zip ties are not interfering

* checked for smooth operation across the axis.  rods are clean and bearings seem OK

* tried with belt "a little tight", "a little loose", "too tight", "too loose" and perfect,  all have made no difference - any value between 58 and140hz onthe belt tuner 

* removed screws in back end of hot end fan,  they may have been contacting z axis screws (no change) 

* held heat bed cable bundle aside during calibration to make sure it's not interfering

Sometimes the calibration will bounce off the left side many (>20) times, other times only a few,  but I always get a fail . 

Posted : 19/01/2026 8:13 pm
Looper
(@looper)
Member
RE: 3.5s+ upgrade, can't get x axis calibration to complete successfully

 

Posted by: @pete-6

I know this problem is posted somewhere else in these forums,  but I'm having the dreaded x axis calibration failure (with no diagnostic message to help) after upgrading my 3s+ to a mk3.5s+, and changing out the pinda for the superpinda. I've literally spent hours on this at this point.   here's what I've checked and tried: 

* verified that zip ties are not interfering

* checked for smooth operation across the axis.  rods are clean and bearings seem OK

* tried with belt "a little tight", "a little loose", "too tight", "too loose" and perfect,  all have made no difference - any value between 58 and140hz onthe belt tuner 

* removed screws in back end of hot end fan,  they may have been contacting z axis screws (no change) 

* held heat bed cable bundle aside during calibration to make sure it's not interfering

Sometimes the calibration will bounce off the left side many (>20) times, other times only a few,  but I always get a fail . 

I am seeing the same thing here. 

Installed new 3.5s+ kit, and heat bed, on a MK3 that had been updated to a MK3S+.  The MK3s+ had been printing fine and had passed all calibration test a week prior to this upgrade when I upgraded it from an MK3.  

I have completely disassembled the the X/Z rods, verified bearings are in the right clock orientation, re-lubed bearings with Prusa Lube. Assembled everything and tried it with the belt too loose, too tight and just right.  no improvements.  still a red X on the the X axis.  Nothing is hitting everything moved freely. 

I have looked over the Crash docs and verified everything on that list.  Anyone with any ideas?

The original MK3 had very few hours on it as I never used it much, maybe two days of print time.  I bought it new to use with an MMU1 that got upgraded to an MMU2. It then sat in a corn for a few years and I just dug it out to upgrade it and the MMU2 to a MMU3.  Was hoping to gain some speed with the MK3.5S+ upgrade.

Posted : 03/02/2026 9:10 pm
Looper
(@looper)
Member
RE: 3.5s+ upgrade, can't get x axis calibration to complete successfully

OK, I think I found my issue.  I got a successful X Axis check.

I changed the X stepper pulley and slid it out, away from the stepper motor, just a smidge.  The only thing I changed to get this to pass a test.  The only thing I didn't change prior to that.  Basically I tried to make sure it was tracking true with the belt.

 

Hope this helps someone.

Posted : 04/02/2026 1:17 am
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