This is the part that attaches to the device and mates with the mount. Can be used with the Action Cam Parts (http://www.thingiverse.com/thing:649261) to provide additonal options for mounting cameras.
It can also be used to repair a broken mount. Please note instructions before proceeding.
STEP file included for modifications.
April 27, 2017 adjusted the top locking grooves to be slightly wider and deeper for a more confident locking feel. Both STL and STEP files have been updated.
What I did to recreate this part
I took caliper measurements from two separate Garmin Edge devices, they were not new at the time but fit snugly in the OEM Garmin mounts. Made a few very slight adjustments to the design to account for using a 3D printer as a manufacturing technique. The model was designed in Fusion 360.
Do not print this part with any type of brittle filament, such as PLA. It should also be printed with 100% infill since it is a high stress attachment. Since the measurements are precise, please make sure to account for normal plastic shrinkage or the part will fit loose.