Anyway, back to the project, the fiddly bit was finding an epicyclic gearbox that wasn't too big and needing a fair bit of power to turn it plus an axle and a motor and a means of getting two paths of power to the wheels etc. etc. Then one day I had an idea which would reduce the size and solve a couple of issues, so off I went to the local mobility shop who kindly let me rummage in their scrap bin and have a couple of rear axles from old mobility scooters. My thinking was to use a differential as an epicyclic gearbox, and the scooter axles size made it much more manageable for me to handle.
The next bit was to sort out how to drive the diff, and I had to decide on a power unit to suit the size of the axle.
I came up with the idea of using an engine from a strimmer, seemed about the right size for it, just needed a way of sorting out how to transmit the power. Didn't have a great deal of choice so I used some bicycle bits to do it with.
Here's the first stage, now don't laugh,,,,,,
I used a 25cc engine from a strimmer and modified the centrifugal clutch to engage at a higher speed, as I found it didn't have enough guts at the bottom end. I then welded a bike sprocket to it as I wanted to drive the diff at a higher speed than the electric motor could manage. The diff ratio was 20:1 so driving through the motor shaft was no good, I needed to modify the crownwheel to alter the ratio.
To be continued.....