Filament Guide for Monoprice Ultimate / Wanhao D6 Spool Holder, Top-Mounted

_Edit: I still like the spool holder, but I'm going to try https://www.thingiverse.com/thing:1664313 instead. When printing a large circle, the filament still popped off the side of the spool and I'm going to be doing a lot of ABS printing, so need something that will allow a top enclosure._

I like the spool holder but I was having trouble with the filament popping out from the sides and getting stuck under the spool. So, I added a filament guide that clamps onto the dovetail rail of elenaut'