[EricH]

I've been running horizontal timing belts for a little bit, off a FRC robot. I don't think you would need it quite this tight, but for the application I've been using them in, if the driving motor started to turn, the belt needed to start to move immediately. If there was delay, I'd hunt down and remove the slack.

For an FRC robot, you don't have to have them that tight, but you still don't want much slack.