The stack lives inside a plastic tube or pipe. In our mechanism, we separate the stack from the dispenser. It has a piece of plastic the height of one coin, and it pushes the coin from the bottom of a large stack. The design was borrowed from a change dispenser that I have in my old coke machine. I had some success printing them using these: servo arm CAD Ultimately we used the servo arm that came with the servos, and overlaid a laser cut piece of wood. I created the models using openscad: Chocolate Coin CAD files The servo horn needs to be longer than the standard horns that come with the servos. I used this as an excuse to purchase a Taz Lulbot 3D printer. The first prototype was built from cardboard and scrap wood. The first part of the project was figuring out how to reliably dispense chocolate coins.
