Nice little project. You could start by counting the teeth on each gear, measuring the diameters to the tips of the teeth, and measuring the diameters of the axles/spindles/rods. Do you have a micrometer? If not, I can help out by opening one up, stripping it down, and providing these measurements.
P.S. it's donor. Doner is a kebab and Donner is a reindeer. Just saying, in case anyone was confused!
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P.S. it's donor. Doner is a kebab and Donner is a reindeer. Just saying, in case anyone was confused!
![Rolleyes Rolleyes](https://www.blueplastictracks.org/images/smilies/rolleyes.png)