Constant Y Axis Crashes
Having an excessive amount of Y axis crashes, where during a print, X axis will home (all the way to left) and then Y axis will home (all the way to the back), and will knock twice to back (mechanical stop), and then both X and Y will return to where left off in the print and start printing again...
Believe this has happened both from SD card as well as from Octoprint (Raspberry Pi WZero...Have checked Y belt (275), maintained the rails...what am I missing? have video which depicts
Belt Test from Calibration Menu
If you have not already done so then I would recommend performing this test and check the values against online guides. If the values are less than 250 then this could be an indicator of what is causing the problem.
Follow up on Root Cause...
Thanks Brad, I have run multiple times before...y axis usually comes up 260 - 275...so appears okay...I have been running prints from SD instead of Octoprint with unsupported Raspberry Pi Zero...I thought I had seen these with an SD run, but I may have been mistaken...
I am assuming the motion control algorithm would do an auto-home to recalibrate position should it detect some variations of slipped gear, skipped belt, loose/excessive belt ... hence the autohome when there's an apparent x or y axis crash...
I'll probably tighten the y-axis after so more baselines...with SD only should it continue...appreciate folks weighing in...its one of the great benefits of owning a PRUSA!
Probable Root Cause
So, as was probably obvious to most, I did decide to tighten the y axis...discovered both belt block bolts were fairly loose...so while I was getting consistent reads above 240 on y axis...I should have noticed that the pre-test to post test values varied quote a bit ~15 counts on successive belt tension tests...after tightened and secured bot belts...consistent pre-post y-axis belt tension with 3 counts...this may have been an indication, had I paid close attention to!