Every time I unscrew the heat-sink fan screws to remove the stepper motor, I find the fan guard flops about and gets in the way. So I have created this retaining clip that simply snaps into place and holds the guard firmly against the fan regardless of whether the retaining screws are removed.
I recently upgraded my fan to a 24v 40 x 40 x 10 mm ball bearing fan which has a higher CFM air flow but lower RPM - so its much quieter. Highly recommended upgrade!
This clip was designed using an ACIS solid in Shark FX (sfx file included) so will behave well with Makerware, ReplicatorG and skeinforge.