school project- electric motor problem

[jc89]

Hello, I stumbled across this forum/website while looking around for information on electric motors.

I'm working on a school project that involves a vehicle driving a course with an average of 15 mph.

We have a brush motor that is 48v/1000W http://www.monsterscooterparts.com/48-volt-1000-watt-electric-motor-11-tooth-8mm-05t-chain-sprocket-my1020.html

we have an energy source of 1000W charging a battery that charges the motor.

the sprocket from the motor was switched out with a bike sprocket and adaptor. and it's attached with a bike chain to a back wheel.

the vehicle's weight is around 150lbf and the driver is 110lbf (if the weight is relavent)

we tested the vehicle and found that it would move about 1"-3" and then the motor would sound like it was being forced(???) and would not move. Yet when we gave the vehicle a little push it would move very slowly.

My question is, (Sorry for the whole back story), do we need a different motor or is this motor good enough but we just got a bad motor?

Thanks you for reading this post.

 

[Doc Sprocket]

I'm NOT an electric guy. But that motor sprocket looks kinda large. Maybe you're overgeared? Perhaps a lower gear ratio is in order?

 

[jc89]

Thank you for the recommendation. Part of the problem was that the gear ratio was almost a 1:1, once we fixed it to 3.75:1 it was spinning better without a load on it. Once we put the car on the ground, there was not enough 'push' for it to move. We found out that it was the motor that was bad, and we changed the whole design.

 

[Mato]

You probably know this, but the cool thing about electric motors is that max torque is available almost instantainly. Added with a fine gear ratio and you shouldnt have any problems. If you know how many RPMs will your motor spin we can help you find a better gear ratio so you get to 15 miles/hr with some more accelaration if possible (once you get your new motor).