Difference in motor speed

Nope
No. The point is that the axles rotate freely in the end holes.

then how can you turn the
then how can you turn the rotation sensor with the differential? i don’t get how it can start turning if the axles are rotating freely

It’s the difference…

EXCATLY. The rotation sensor will not turn if the axles are going the same speed inthe same direction!

Differential gears are so called because the output of the main gear is the difference between the other two. Mechanically, they can, of course be configured as adders.

ah ok i got it now, thanks
ah ok i got it now, thanks for the infos mate