Yeah, it’s a bit different than backlash here… but yeah… I know… It’s not needed really because during a print it’s always going in one direction so the slop like that on a 3dp doesn’t matter. The backlash (to my understanding) happens all at the change of direction point. This was more… energetic and rhythmic and happening 3 or 4 times every 10 mm.
I was also starting to have issues with it sometimes putting down a great first layer and sometimes not. I’m doing some huge prints so it suddenly matters (apparently… I’m a bit new to 3d printing). I checked the tightness on everything and it was ABS tight to me.
I started looking and poking and I think I figured out what was up on my bot though. One of the two motors in Z had spun independently about 1/2 turn or maybe 1.5 turns too much. Not sure how, but easy fix.
I ran the machine through a cross pattern calibration and it was fairly clear. I was able to carefully rotate the motor coupler while the machine was running (since I’ve watched quite a few cals now I was aware when Z fires I was ok with the risk) and thus quickly tram the machine back in. Sorta. Anyway, after doing that the clunking stopped. I did the normal cal thing and everything pretty spot on. I also wiped down the ways… er… rods? with some kimwipes and the low pitch growl stopped.
I think I’ll invest in a dial indicator and tram the machine out as part of my calibration routine.