This is a remix of two different designs found here. The remix was created to elevate an annoying sound that was generated as the airflow around the center part of the velocity shroud produced a high pitch whine/whistle. The second part of this remix was adapted to provide protection from items falling into the fan blade.
The guard should be printed flat side down and both can be printed without supports.
This was printed using PLA .175mm layer height @ 25% infill.
I hope someone finds this remix useful. Feel free to share your makes.
Designed to use stock screws on the monoprice select mini.
The original makes were imported into tinkercad and then joined, cleaned up and split into two parts so that the guard could be printed upside down with no supports.
Here is an image of the physics behind why a velocity shroud helps pull more air through your fan.