I’ve spent a lot of time watching the current prototype climbing over large obstacles and it appears that when it’s in an awkward position it might be very useful to have complete control over which wheels have power going to them. If the motors are embedded in the wheel hubs then this would be easy to achieve. The only thing that needs to be given much consideration here is the user controls. The image below shows an initial concept of what these controls might look like:
Whilst this is just a concept, research could be done into ergonomics and inspiration taken from gaming controllers:
As mentioned though, delivering drive to individual wheels is easy if each wheel has an embedded motor. If one motor is used for each side of the vehicle, so one motor for three wheels, it becomes far more complicated. I’m not sure how this would work but I imagine it would have something to do with engaging and disengaging gears.
I’ve been spending a lot of time thinking about motors and really like the simplicity of having a motor embedded in the hub wheels.
Being able to use a solution like this would save a lot of engineering work in terms of building axles, hubs, and a method to transfer power from the motors to the wheels. You often see these hubs with 10″ wheels for mini-motos and e-bikes and the like. At present I think a 10″ wheel would be too small. I’ve also seen a lot these hubs embedded into bicycle wheels like this one which is for sale on Alibaba.com and is available with a 16″, 18″ or 20″ wheel.
16-20 inch Alibaba wheel
At the moment, I’m not wholly confident that a thin wheel like this would provide enough traction, however, whilst thinking about how the wheel could be attached to the frame, it did give rise to another prototyping idea…
It wouldn’t be too difficult to make a very quick but full scale mock-up using second-hand bicycle parts.
Bicycle Parts Mock-up