![my first (working) automatic gearbox! By any chance, is it uncommon to use pull back motors for this? it seems like an obvious choice, but i always see people using non-lego springs : my first (working) automatic gearbox! By any chance, is it uncommon to use pull back motors for this? it seems like an obvious choice, but i always see people using non-lego springs :](https://i.redd.it/k7ohyv6oo5f71.jpg)
my first (working) automatic gearbox! By any chance, is it uncommon to use pull back motors for this? it seems like an obvious choice, but i always see people using non-lego springs :
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Sliding worm 3-speed automatic gearbox - LEGO Technic, Mindstorms, Model Team and Scale Modeling - Eurobricks Forums
![Simplest automatic LEGO transmission in the world? Really functional. Principle explained. - YouTube Simplest automatic LEGO transmission in the world? Really functional. Principle explained. - YouTube](https://i.ytimg.com/vi/TjhBIw50gFk/maxresdefault.jpg)
Simplest automatic LEGO transmission in the world? Really functional. Principle explained. - YouTube
![LEGO MOC 2 Speed Automatic Gearbox - Smooth & Compact by TechnicBrickPower | Rebrickable - Build with LEGO LEGO MOC 2 Speed Automatic Gearbox - Smooth & Compact by TechnicBrickPower | Rebrickable - Build with LEGO](https://cdn.rebrickable.com/media/thumbs/mocs/moc-51810.jpg/1000x800.jpg)