Geeetech A20 Hotend Fan Duct

I recently wanted to change my A20M to a single nozzle printer (to eliminate the right angle turns built into the mixing hotend). In the end, I think the design will likely work for an A10/A20 or A10M/A20M. You'll have to let me know.

- I upgraded the hotend cooling fans to 40x40x20mm (24V) versions (many on Amazon)
- I also upgraded the part cooling blower to a 50x15mm (24V) blower (many on Amazon)
- The cooling fan on the left side needed a fixture to move it out so it doesn't hit the