My first attempt at designing and 3D printing a gear-less "flapping" mechanism (not for flight, well not yet) with symmetric rotational velocity, in a small space. There is room for improvement in both size and weight, but this test indicates the concept appears to be feasible.
I remember a display at the Boston Science Museum that had a ton of different linkages like this. They had everything from planetary gears to differentials to pistons and crankshafts, and everything was chrome plated and you could move each one by pressing a button. That display entertained me for hours, and your mechanisms bring me right back to those days.
Hi Dan!
I'm glad you enjoy these mechanisms!
From time to time I design mechanisms such as this as a test for a future project, and in the process I come up with other uses for them.
This mechanism will be put in use soon!
Greg