Awesome Printrbot 40mm Fan Shroud by Molten Plastic 2.0
This shroud doesn't need any support. you may need to sand the bottom, you may even need to shave the inside of the bracket to account for hex nuts on the extruder shelf. (if you have square nuts on your bolts, you won't need to modify the bracket)
I ran it through my acetone vapor vortex machine.
I have uploaded the most current version of the file. I had mistakenly uploaded the beta! The working version is the version now available. Sorry folks!