Tolla

I seem to recall the first posts regarding lubrication of the belt had nothing to do with lubrication of the belt at all but everything to prevent the build up of static electricity which was perhaps causing glitching with some radio systems.

The idler pulley is the small wheel at the top of the tail case. IMO it is there to push the belt down by just a little bit to clear the top of the tail case. I have removed my idler pulley to have a closer look and with the pulley removed the top of the belt definitely touches against the tail case connection screw that is located just in front of te idler pulley. This is an aluminium Copter X tail case. This may not be the case with all tailcase assemblies, I suppose.