If you were a kid that grew up with Legos, then you are a lot more likely to understand the fun of the gear set. You can scale it to any size you want and it's still a 3:1 ratio :). The gears should be 100% fill though to prevent any delimitation under gear loading. The shaft is press fit, so use a rubber hammer and a socket over the shaft to assemble to the pinion. with the Have fun!
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