Welcome to the SeeMeCNC Community

Assembly Guide says to tension belts, but doesn't have a measurement.
Shown is the Green Bean Needle Nose method, where by 2 large cans of green beans were suspended
from needle node pliers arranged to apply tension to belt.
Also helps with not having 3 hands to tighten tension wheel nut and bolt.

This may work with other vegetables, but has only been tested with green beans!
Actually, only one brand of green beans. But it would be silly to think a different brand would matter.

PS (This post is mostly for a laugh,
but prior to this I did get one tower too tight and it bowed the aluminum very slightly.
So I did this to make sure I applied the same force to each belt.)

Someday they will come out with something to put the proper tension on a belt but I don't think that day is here yet.
But yours is worth a good chuckle! Most unique belt tensioner award should be given!

I'm partial to the Canned Peaches Needle Nose method myself. Of course, only the highest quality canned peaches will do.

LOVE IT!