The following is more of a Photo blog, of our attempt to prototype and design a vehicle for our Moonbot mission.
We started off with trying 2 basic design
- Tank Track based, with 2 driving motor.
- Car Based (4 wheel) with a front steering system.
The front steering wheel mechanism is really simple (anyone knows the name of this design?). It is just motor connected directly to the steering arm. No rocket science. Simple and effective.... However this design does have a tiny flaw.... it is difficult to get a good turning accuracy, as well as the terrain and ridges sometimes pushes it out of alignment.
We did a redesign it and tried it with a differential drive train. It worked very well when the vehicle is on flat terrain and when it is turning. However when faced with uneven terrain as well as Moonbot ridges, sometimes when all traction was lost to 1 wheel, thus transferring all the energy to the other wheel, causing inadequate traction and power to cross the ridge.
I reckon if we could try a limited slip differential, it could work. However with complicated design, it also could mean that the vehicle could be more unreliable. We decided not to try that design and just stick with the simple design and work within the limitations.
Overall over the 2 days that I spent with the kids, it was great. We had many brain storm sessions, prototyping most of the designs we wanted to try and then decided which was the one that should be used. It was good as it wasn't my duty to dictate which is the best direction of building the best vehicle but give the opportunity to the kids to prototype, trial and decide.