Building an e-gokart for my son with ebike parts

[billyjones454]

I initially purchased parts to build 2 ebikes. 2 controllers, 2 motors, 2 throttles, etc... One was going to be for me, and one for my wife.

I have a 7 year old son, and since I'm not getting much use out of one of my ebikes, I thought I'd re-purpose the parts for a gokart.

My question is - I have a Lyen 40a sensored controller - What motor would be compatible? How can I calculate gearing.. In short - where do I start when selecting the motor?

Thanks for any advice!

 

[Drunkskunk]

That controller would be fine for many motors. Its designed for lower RPMs found in Outrunner style BLDC motors, and of course with sensors.

What speed are you looking for out of the gocart?

For gearing you need to know the KV of the motor (The motor's RPM per volt ), the wheel size, and the speed you want to achieve.

 

[billyjones454]

Thanks for the reply!

I think 20-30mph tops.

 

[Drunkskunk]

Thanks for the reply!

I think 20-30mph tops.

So roughly the speed of your Ebike then?

That makes it easy if you want to use your ebike motor. Unlace it and attach a gear, then you can drive your gocart wheels.

The gear ratio will be the same as the ratio of diffrence in diameter from the Ebike wheel to the gocart wheel. If the Ebike was a 26" wheel, and you use an 8" gocart wheel, your ratio is 3.25:1 . Of course, a 1 tooth gear is impossable, so multiply both sides by some thing more practicle. Say a 15 tooth gear wheel gear. that would be 48.75, so a 48 tooth gear would be close enough on the motor.