Big wheels, big problems

The wheel posed us a problem - how do we mount it onto the differential axle? The hole was too big for the axle and we did not have the appropriate bearings and mounts. We also considered making a hub in the centre for holding the wheel but it wasn't feasble since there wasn't anything to latch onto the wheel.

After much consideration, we ended up drilling two holes through the shaft collar and securing a circular wooden piece on to the shaft collar. The wooden piece used the holes on the rim that were meant for the wheel chair's hand rim to latch on to the wheel.

And this was merely the beginning of our problems...