Hi Tom, ABS is a great choice as it’s tougher than other common materials like PLA and PETG. Nylon is also a good choice but not all printers are able to print it. There are empirical methods to calculate the exact dimensions of the snap-fit mechanism to ensure the maximum cycle life, all you need are the specific material properties of the ABS. These equations are for injection molded joints but should still apply for 3D printed joints, just don’t expect your 3D printed joints to last as long as injection molded ones. As an alternative, you can also explore using heat insert fittings so that you can screw the parts together because ultimately injection molded snap joints will always perform better than 3D-printed ones.