Lego Technic PU 2 Speed Automatic Gearbox
This video presents a lego technic two speed automatic gearbox using two motors and the Powered Up (PU) lego technic control system. Each motor uses a pivoting gear to either connect to it's gear to the left when rotating in the forward direction or to the gear to the right when reversing. This allows the gearbox to switch between four different states to produce a high gear and a low gear in the forward direction as well as a high and low gear in reverse.
The motors are disengaged from the main gearing output by moving the pivot to the center.
The high gearing ration is 4/9 and the low gearing is 4/27 (one third on the high gear).
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