Belt Tensioner for OpenAstroTracker

thingiverse

An addon for the OpenAstroTracker. The current splitring uses M3 bolts directly pressing onto the drive belt. This is not good for the belt if you slacken/tighten the belt between uses as it can easily punch a hole in the belt if done too tight. This addon bolts onto the end of the splitring and uses a notched wedge that is tightened with a winged bolt to hold the belt. This is much safer for the belt and the winged bolt should mean your belt will get loosened more often when the OAT is not in use. The bracket is held in place using the hole for the original belt tensioning screw. It really requires a thinner headed bolt than the normal ones for the OAT, I had some button headed M3 bolts which worked perfectly. If you don't have any suitable bolts, don't think this will be secure enough or the hole in the splitring is too worn to take a bolt, there are 2 holes on the sides that will take self-tappers or a long bolt drilled through the splitring. The Wedge has a recess for an M3 nut and the Wingbolt head takes an M3x16mm bolt. To get the belt into the slot, I used a thin strip of plastic from a blister pack. Thread that in from the top (the thin slot) then lay the belt on the strip. Pull the strip with the belt back up through the slot. You can use a tensioner on either or both sides, one should be enough though as you need only slacken/tighten from one side.