The apparatus is to be purely mechanical and hand operated. With the input of a 20ct-coin the machine should output one little chocolate bar. The ALDI Moser-Roth chocolate package (found in Germany) contains 50 pieces measuring 5mm x 35mm x 35mm each, which are cheap and stack well (see the picture above). The coin-acceptor unit is to make possible the chocolate output with one 20ct-coin. Other coins with a smaller diameter should fall into the return area.
For all of the competition details visit KugelbahnBlog starts TINKERING COMPETITION for chocolate vending machines.