Pink gear, four yellow satellite gears, two blue gears and green carrier create a differential planetary drive.
The yellow gears and the pink spur gear have same tooth number.
The blue gears have same tooth number.
Input: green carrier rotating regularly.
The yellow gears have unchanged direction during rotation while the pink gear is immobile.
Use the orange worm to rotate the pink gear for adjusting the direction. The video shows 45 deg. adjustment.
This mechanism is similar to the one in video “Keeping direction unchanged during rotation 9a” but uses less gears.