What do belt tension numbers mean?
Does a higher belt tension number mean the belt is tighter or looser? Intuitively, I would think higher=tighter, but a comment in this review ( https://lib.reviews/original-prusa-i3-mk3 ) suggests the opposite. I want to know before I start adjusting my belts. I think they are too tight given the tone they make when plucked, and have tensions reported as 280 (maybe ok) and 286 (maybe not).
RE: What do belt tension numbers mean?
Belt tension numbers are based on motor current measurements reported by the TMC drivers. They are meaningless for belt tension. They tell you more about the axis friction than anything else.
As an example, I simply changed bearings and tensioned the belts to the proper Gates spec and my Prusa numbers went higher by 20. Just the opposite of what is expected. Lol.
The only reliable way to test tension is the deflection method. Apply about 8 ounces of force to the belt and it should deflect about 15/64" ...
I've gone as high as 2 pounds at 15/64 ... but that exceeds the motor shaft axial load specs a bit.