Axis calibration issue
Hi all,
I have managed to build by Core One from the Kit but now I am seeing two issues with the axis:
1. On job start there is always a X/Y calibration in the front right corner. This took really long initially, but tightening the right belt tension screw fixed it. It still calibrates a bit before every start (see video). Since my last printer was a MK3S+, I am not sure of this is normal (since it's quite loud) or how to further get rid of this.
2. The front right Z-axis makes a very worrisome sound at mid height (hear video attached). Any idea what could cause this and how to fix it?
Cheers,
Jannis
RE:
Two things you can do:
(a) Make sure that there is no lateral strain on the trapezoidal nuts on the lead screws. It's the smooth rods which define the XY positoin of the heatbed, and the lead screws/nuts need to accommodate that position. Move the heatbed all the way down, and loosen the two screws holding each of the three trapezoidal nuts. That lets the nuts move to the right position. Then gradually re-tighten the six screws; do not overtighten them.
(b) Lubricate the lead screws lightly with the included lubricant. Yes, they are meant to run dry, since the POM nuts are supposedly self-lubricating. But various users have reported nasty noises or even sporadic blockage of the Z drive, which went away after lubricating.
Fingers crossed, but I am pretty confident that your Z drive will be quiet afterwards.
EDIT: Oh, and the X/Y headbanging is unfortunately normal, as long as it only occurs a few times as in your video. But many users are unhappy with it. There's an open Github request here: https://github.com/prusa3d/Prusa-Firmware-Buddy/issues/4582
RE:
I agree with Jürgen's suggestions, particularly part (a). The fact that such a step is not part of the build manual is a bit weird.
Before you lubricate the screws I would check to see if there is nothing stuck in the threads. I watched 3d printing noob's stream on the kit assembly and he found that one of the lead screws had some sort of hard residue inside the threads. He scraped it off with a brass brush.
RE: Axis calibration issue
Lubrications eliminated noise from z axis on my printer, not much but still annoying enough to address. Interestingly careful alignment of the x axis squareness and belt tuning more or less seem to have eliminated excessive head banging on my printer. The printer now consistently just do two bumps in each direction and is done, this surprised me. Mine was of as little as 0.4mm at the right bracket and 0.5mm on the left measured with feeler gauge, I ended up printing a 0.4mm shim in ASA to square.
/Anders