It was all going so well

Until the stepper gremlins showed up.   My printer is eating Pololu Stepper Drivers.  At 8 quid each.

I got a new stepper yesterday and after carefully plugging it in and doing an initial test everything was hunky dory. It was running at .4v as measured between ground and the trimpot. My other steppers are all at .5v but I thought I would start lower as opposed to higher. So I print some calibration objects and everything is still hunky dory. I print a fan holder in white cause the one I am using does not match the rest of my parts. It prints fine. So I print some more calbration parts as I am iterating iterating iterating. Everything fine. I go to bed. The printer does as well.

We both wake up this morning and I go to print another calibration test. The printer gets a short way into the print and the x-axis skips. I checked the voltages again and every thing was as I had left it. I have adjusted the voltage up on the x-axis and am reprinting and everything was working for the first 60 or so layers then the x-axis slipped again...though not nearly as much as above (2 cm versus 2mm).

...BUT...

Nothing changed between last night on the x-axis. I did tighten the y-axis timing belt but that is the only change. Could that have caused enough additional current pull from the y-axis to cause the x-axis a problem given my lower amperage adjustment there? I am concerned because, as stated above, I seem to be eating steppers and this working, not working behaviour, has been observed before!

I am calibrating for layer consistency on x-y axis. Looking great on the Y-axis and all but two layers of the X-axis. Then I can work on the whiskers.