This is a remix of the (brilliant) design made by marcelomorais, found here: https://www.thingiverse.com/thing:5978144 - This remix still keeps the great & easily attachable mount in tact, but makes it more easily printable.

We decided to cut the design in half and add holes in the corners to mount the two pieces together with bolts (4x m2*6). Our motivation for this was to make it easier to print. This change also results in the overhanging parts being stronger when printed in this orientation.

The GoPro mount fits perfectly tight in this mount. We did not place threaded inserts in the bottom part as the bolts itself are enough to secure the two parts together VERY tightly. The bolts are absolutely not coming out in our case (check for yourself, on your own risk, you can of course still choose to add threaded inserts if you'd like).

The print in the sample pictures was done in PETG at 100% infill, at 35mm/s - The object shrinks a tiny bit but was still printed at 100% size, this makes the GoPro mount fit super tight, which is exactly what you'd want.

We used TREE / ORGANIC supports, even though I guess it is also possible to print this object without supports at all. That's up to you.

Be ware: The holes in both pieces are 2mm, if you are going to use threaded inserts it might help to make the holes on the TOP (GoPro side) piece 3mm so you can smelt the inserts in more easily.