e10 & e12 hotend shroud (50mm radialfan for part cooling)

I took the beautiful shroud of Jacks-Filament and optimized it for a 50mm radial blower fan.

In addition I remixed the fan duct of locki (https://www.thingiverse.com/thing:2174921) for my needs and better view on the nozzle while printing and for manual bed leveling :-)