3D printer belt tension seems like a simple thing to deal with — you set the tension and then check it’s good now and then. If it gets really loose, then the teeth can slip and you’ll get some shifts in the print, ruining it, but its an easy fix. But, we hear you ask, how do you determine what the correct tension is? Well, here’s [Lost in Tech] with a video showing some measurement techniques and analysis of a typical 3D printer, (video, embedded below) using nothing more special than a set of luggage scales. A simple theory suggested was that a tighter belt tension would result in increased radial load on the stepper motor bearings, which in turn, due to friction, would result in an increase in temperature of the motor. After setting a few tension values on one of the belts, it was noted that tension values at the upper end of the range, resulted in a measured increased in temperature of two degrees celcius, and a large increase in noise. This can’t be good for the motor.