Remix of Carboy Stopper Clamp from @TheWalrus with additional reinforcement and 10mm stopper height (instead of 5mm). The original is well designed, and this has just a few minor tweaks. This device keeps wet stoppers from slipping out of glass carboys used for homebrewing.
I printed the original Carboy Stopper Clamp initially, but it separated under the pressure from the stopper trying to come out. The failure point was at the thinnest point of the sidewall, just at the top of the carboy.
The sidewall is now at least 54% wider at this point, and a curve was added to the exterior. As mentioned above, the gap for the stopper is now 10mm instead of 5mm, which seems to be about perfect for a #7 stopper with an airlock in both a 6.5gal and a 5gal carboy. I would also recommend printing in the default orientation (upright), so that the clamp has a higher tensile strength against the upward force of the stopper.
If you use a #6.5 stopper, or your carboy has a wider mouth than mine, you should reduce seal_h in the model.
Printed with a 15mm brim in PETG. I would highly recommend printing in the default orientation (upright), so that the clamp has a higher tensile strength against the upward force of the stopper.