Ever wonder how tight your belts should be on your printrbot or any 3d printer? Well thanks to redditor /RememberToBackupData, somebody posted a good way of doing this.
I use a guitar tuner app to help me get my belts consistently tight. I traverse the stage or arm so that it's furthest away from the belt tensioning screws, and then I strum the belt and ballpark the sound around 150 hz. Do note that I just picked 150 hz arbitrarily; I couldn't find any advice about how tight a belt should be except the eminently helpful, "Not too tight and not too loose." I think the design of the Simple makes perfect belt tightness unimportant, but I feel that having a benchmark for consistency is a good idea.
The guitar app "Chromatic Guitar Tuner" is on the apple store: https://itunes.apple.com/au/app/chromatic-guitar-tuner-tune/id662890455