Originally Posted by SethAZ

Hi all. I just wanted to point out that for designs like this one shown above, this is going to be a very fragile part. This was printed on an FDM printer, so the layers are built up with the plane of each layer perpendicular to those vertical surfaces where the GoPro mount would actually slot in. Notice the 90-degree corners at the base of each of those slots? Those are heavy stress risers, and are where the focus of any sideways force acting on the mount will want to crack the mount off at an orientation of the layers that makes this most likely.

A good way to handle things like this is to put very generous chamfers or fillets anywhere two planar surfaces meet in your design. Since the mount part that's fixed to the camera doesn't extend to the bottom of the spaces in between the mount as shown above, there's going to be room to put generous fillets there. PLA can be very brittle, and with 90-degree joints between planes, and especially with one of those planes also being the plane each layer is built up on, designs like this look like they work fine until they get bumped sideways and just snap off. A good fillet can make that much harder to happen. Machining metal is much easier without fillets, but a 3D printer doesn't care one way or the other, so there's no reason not to include them in any design. A 3D-printed part designed for maximum toughness will be much more "organic-looking" than what one would want to machine out of metal, simply because printing these organically blended surfaces costs nothing in terms of printing complexity.