What is causing this?

[Zman (MICHAEL ZEMANEK)]

Here is a thread on belt tensioning.

Measuring belt tension, squaring and calibration

A post about belt tension, how to measure it, what effect it has and why you need to manage belt tension in order to usefully calibrate and square the machine. As usual, no criticism of the machine here, in fact some quite clever design choices seem to have been made. The question of drive belt tension has been bugging me. How much you should have, how to check it and how it affects machine performance. I failed to find any quantitative data to use, so I went and started measuring; and found t…