Dual 40mm clip-on fan holder for Ultimaker

This is a fan holder I made with three objectives in mind:

• Two open fans. I'm not a huge fan of fan ducts. Some work really well, but having the mouth too close to the nozzle makes it hard to do maintenance on the hot end.

• 40mm fans. Those are much easier to find than the stock 50mm fans.

• No nuts or bolts (except for those holding the fans). I've tried too many fan ducts and holders, and switching them was a major pain, so I made this clip-on version that just snaps onto the existing bolts. I hope this encourages people to try this design. :)

Inspired by scottvader's good results here:
http://www.thingiverse.com/thing:125244

I'm insulating with Teflon tape for the time being, but MadOverlord's silicone sock should work wonders:
http://www.thingiverse.com/thing:165750

2013/12/08 update: The original model could hit the lower bolt on the Y axis sliding block in some cases. That's now fixed!