50x15 blower duct for Wanhao Duplicator 6 / Monoprice Ultimate

I modified the duct from uncleskippy to accommodate a $7 50x15mm (5015) blower fan I bought on [eBay](http://www.ebay.com/itm/281940091393). I re-positioned the fan so there is no loss of build surface. It's very close at the front-right corner (see the third photo).

Other changes:
- Mounting holes are slotted to allow adjustment (the original wasn't quite centered around my nozzle)
- Mounting holes use the original plastic spacers
- Clip for fan wire on the rear of the duct
- Blower atta