![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 :
![LEGO MOC Lego Technic lockable automatic two speed gearbox [with free instructions] by SJ_LegoFan | Rebrickable - Build with LEGO LEGO MOC Lego Technic lockable automatic two speed gearbox [with free instructions] by SJ_LegoFan | Rebrickable - Build with LEGO](https://cdn.rebrickable.com/media/thumbs/mocs/moc-42462.jpg/1000x800.jpg)
LEGO MOC Lego Technic lockable automatic two speed gearbox [with free instructions] by SJ_LegoFan | Rebrickable - Build with LEGO
![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 Compact 3 Speed Automatic Gearbox Instructions - Lego Technic Mastery - YouTube | Lego mindstorms, Lego technic sets, Lego technic Lego Compact 3 Speed Automatic Gearbox Instructions - Lego Technic Mastery - YouTube | Lego mindstorms, Lego technic sets, Lego technic](https://i.pinimg.com/564x/8f/fe/8c/8ffe8c05d51b153b74f92adb8e7572af.jpg)