Printrbot simple 1405 fan shroud with air flow guide

Modified fan duct for Printrbot 1405. I found that with the standard fan shroud the flow would not flow out straight from the shroud exit (a portion flows away from the duct exit away from the nozzle). Added airflow guides to straighten the exit flow. Not manifold, but slices fine with slic3r for me.

Note : requires longer screws than standard for fan shroud, I swapped with tightening screws for Y axis belt.

Cheers,
Mupp