17 replies

V-Core 4 400: 3 peaks in belt tension + Y axis weirdness?

📉input shaper

I've recently finished building my V-Core 4 400mm and I've reached the calibration stage of the commissioning guide.

I'm trying to understand what I've got going here, the X axis input shaper graph seems fine but the Y looks suspicious (low acceleration and everything between 75-150hz) but I don't know what to look for.

The printer is on the floor.

What I've tried so far:

Tightened X linear rail.
Took belts out, checked for X/Y binding, seems fine.
Cut the belts to the exact length.
Rerouted the belts so that both belts are tightened to the same tooth.
Made sure both belt tensioners were the same length.
Frequency matched them to 87hz.
Checked gantry squareness on the rear XY joiners.
More zip ties on printhead.
Tightened idlers on X gantry.
Made sure belt is centered on drive gears.

I've added the belt tension, input shaper and real time analysis graphs.

The real time analysis graph macro is the one from the ratos guide (https://os.ratrig.com/docs/guides/real-time-analysis/#custom-power-spectral-density-graph-macros).

I'm hoping someone can point me in the right direction