Nice design. I would appreciate it if you point out that one should think about the food safety of the filament and the printing process. 3D printing is becoming more and more popular and with it the number of black box users is growing and yet the terms extractables, leachables and contaminations have not really made it into the jargon of the 3D printing community.

We plan to test and develop your tempering procedure on 3D printed prosthetic devices, and it will be nice to use your cup and saucer as controls. Being able to put a terminal device into the dishwasher will add to an amputee’s confidence that their “hands” are clean. I try to design hollow devices with 1.6mm wall thickness (which means no internal overhangs and no infill). A pair of venting holes will also allow water drainage and will allow the same STL files to be used with SLS printing (like Shapeways), but that will require printed plugs to keep the water out when washing. My hypothesis is that this maximizes uniform heat transfer in and out of the part (as with injection molding). Thanks for the excellent tutorial!