I have designed arcade butto for a DIY project of mine. The design is very simple and uses commonly known tactile switches as seen in the pictures. I have only tested the butto with the 6mmx6mmx5mm diameter. 6x6x4,3 and 6x6x6 will probably work too. A source for 6x6x5mm butto: A hole with a 15mm diameter is needed for the itallation on your project. Enjoy!