Experiments with paper gear design.

I've been looking at the gear in the Hippo model to see how it can be improved. In the current design there is this large gap between the teeth necessitated by the need to glue the teeth into place. I was wondering if there was a way I could construct a gear where the teeth are closer together.

This is what I've come up with so far:

The teeth are made from individual sections with tabs to the side to link them to the next tooth. I've printed out the parts twice on two different colours of card so that you can see the separate parts.

Here's a row of twelve teeth ready to be looped round and glued into a closed ring.

With a central support in place the result looks rather good.

I've then constructed a matching twenty three tooth flat gear from from double thickness card.

It feels like it runs smooth but I'll only really be able to tell if it works once it is mounted into a box. Back to the computer.