When we pull the belts tight to lock them in place we want a little counter tension on the tensioners. Tighten the tensioner knob a few turns until the tensioner looks similar to this.

Pull the belts through the front plate so they're tight. I used a few drops of superglue on the smooth side of the belt.

Remove the clamps after 5 minutes. Tighten the zip-ties and cut off the tail and the extra belt length.