Steerable Monowheel
Simple monowheel, or more precisely a diwheel built using the new turntable pieces. Features drive and steering.
Datasheet:
Completion date: 07/11/2016
Power: electric (Power Functions)
Dimensions: length 21 studs / width 10 studs / height 21 studs
Weight: 0.563 kg
Suspension: none
Propulsion: 2 x PF L motor geared 1:11.66
Motors: 2 x PF L
This model was a simple idea for using the new big Technic turntable pieces. It was just a new take on my old diwheel concept. The vehicle was basically two independently controlled motors inside a ring with separate left and right halves. By driving the halves at different speeds, the vehicle could be steered left and right.
There were two essential differences between this vehicle and my 2008 Diwheel: a proportional steering with smooth speed control was possible thanks to the use of a SBrick, and the two ring halves were held together by just a few pieces. They weren’t actually mounted to the “chassis” inside, they were simply braced from the sides and the chassis fit flush inside them. Driving was possible thanks to the chassis’ center of gravity being located outside the center of the rings. This was a fairly sensitive arrangement, which in fact was greatly affected by adding a camera to the vehicle.
I had a chance to observe how important the position of the center of gravity is in making a vehicle like this capable of moving. I originally wanted this model to be fast, so I’ve used two Lego RC motors, along with two SBricks and two 8878 batteries due to the motors’ high power consumption. The resulting model has its inside almost full and was incapable of moving: because its center of gravity was very close to the center of the rings, it would just stand in place and rotate inside the rings, without making them move forward or backward. It was an interesting lesson.
