Geneva Drive Prototyping

Sun, 27 Apr 2014

The Geneva drive is a mechanism use to convert continuous movement (In this case a turning crank handle) into intermittent motion. I’m reworking a previous mechanism to make it slimmer and more compact so that I can use it to drive a crank. This blog post show my first attempts.

There is a pin in the main drive wheel that needs holding accurately in place. I’ve turned my previous version inside out so that the parts holding the pin are on the inside leaving the outsides of the wheel smooth and flat, that way it should fit nicely into a slim-line housing without any parts catching as it is turned.

With the outside wall in place everything looks neat and tidy. Total depth 20mm. I could probably get it down to 14mm if I’m lucky.

The Geneva cross part is made from double thickness card. It is intrinsically flexible so the pin on the drive wheel needs to be long enough to allow for a certain amount of warping.

Hopefully the whole thing will fit on the outside of a box like this. Inside the box the Geneva cross will be connected to a crank and then onto whatever character is being driven.