Modified FatGeekyMan's tool a bit to have more round corners. Also added a modifier part to add stiffness to teeth and handle while using a low density infill to reduce overall filament usage. External bearing bottom bracket wrench compatible with: Slicing using Slic3r's modifier part feature: https://youtu.be/kdgvXvhe9msPrint using ABS or similar tough material. If you don't want to print the whole object with solid infill you can use the avvain_vahvistus_rev2.stl model as a modifier part to add stiffness to the inside of the model and to the teeth of the wrench.