PSA: Check belt tightness at the Nextruder holder before adjusting tensioners
Prusa is updating the Core One belt tension guidelines, raising the target from 85Hz to 98Hz. This means you will likely need to tighten the belt tensioners.
Be careful. If the belt is too loose at the Nextruder holder, tightening the tensioners alone can push the carriage too far and strip the nut inside. It took me two tries to realize the real issue was slack at the anchor point.
To fix this properly:
Step 1: Loosen both belt tensioning carriages until they are almost off.
Step 2: Remove the Nextruder to expose the ends of the belts.
Step 3: Tighten the belts where they anchor to the gantry. They need to be quite firm—tight enough to produce an audible tone when plucked.
Once that’s done, reassemble and fine-tune with the tensioners to hit the new frequency target.
