Raiscube A8R X upgrades

This is an upgrade of the X belt clamp / cooling system for Raiscube A8R 3D printer. This unit comes with a quite cumbersome extruder assembly, with a highly ineffective but very huge cooling system. It uses a couple of 40mm axial fans, each with an air duct and a very narrow exhaust nozzle, so air movement was barely zilch. I had to do something with it :)

Same time, I wanted to make the usual, cable-tie type "belt clamp" somewhat better. Here I was hesitating for a while, what solution to choose for the variable clamp (tightening side). I was first thinking about something with a screw, then I saw a solution which was developed for Anet A8 printers, using a rotating ratchet wheel and I really liked it. Unfortunately here I had no space to implement this, so at the end I came up with a simple curved belt duct and a little wedge. One can pull the belt tight by hand, and then push the little wedge in to lock it. Belt tension tries to pull the wedge even more in, so it will self-lock