PrintrBot Blower Fan Mount

[Studies have shown](http://www.desiquintans.com/coolingtests2) that a lot of air in a little spot is good for your 3d prints! I figure a blower fan will really jam some air in there, so why not give it a try?

This is *sort of* a remix, given that I made a new file from scratch, which was inspired by the original! I had a smaller blower fan (27mm x 20mm opening OD) that I'd scavenged from an old projector (they have so many fans in there!), so I needed a model with different opening dimensions.

I've created the file as a parametric Onshape template [here](https://cad.onshape.com/documents/33d36f54c9155f8d7b820fb7/w/f2cf4c431b4a7ed1c043730f/e/e03fa72646ae2262d376cd33), so that if I end up having to do this again I can simply adjust a couple of params + print again!