Wanhao i3 120mm Fan Mount PSU Control Box Back Plate

Korzar designed a very useful 120mm fan mount for the Wanhao Duplicator i3 control box, but unfortunately it is not very suitable for those of us with the older non-sloped front style control box (from V1 and some V2). Also there are a few areas that could do with some improvements.

So I designed a new one based on the ideas of the original, with some useful features -
- Suitable for both old and new control boxes
- 3 part design, TOP / BOTTOM / COVER, which makes printing easier
- Only o