A trike motor

[Posselosse]

Hi, I'm currently running a project in school to create a motorized trike (http://farm1.static.flickr.com/12/22281860_4a53f0cc94.jpg?v=0). I don’t have enough knowledge in motors to be able to find the right one to use though, so maybe you can help me by pointing me in the right direction…

The trike will have a maximum weight of 300-400 kg (660-880 lbs). Its maximum speed with full load will be 10 km/h (6,2 mph) and at the weight of 160 kg (350 lbs) 25 km/h (15,5 mph).

It’s not necessary to be able to use the motor from standstill (if it complicates things for some reason); we will have pedals as well.

What kind of motor should I use? What suppliers are there?

 

[safe]

You didn't mention the steepness of the hills you need to climb.

A good place to start is here:

http://www.me.psu.edu/lamancusa/ProdDiss/Bicycle/bikecalc.htm

...because it can give you an idea of how much power you need. Once you know the power level you can then select a motor.

Another issue is the laws... if you want to be street legal then the state you live in sets the rules for power limits. (motor size)

If you can be an "Outlaw" ebiker (etriker?) then you could pick anything and it sounds like you could use an Etek motor because they are extremely powerful.

http://greenspeed.us/electric_scooter_e-tek_motor.htm

...given the weight you are talking about this is probably what you will arrive at as your choice. It will probably not be street legal, but as a science project it would be okay.

If you want to be street legal the odds are you will need to use a very small one horsepower motor and gear it way, way down to build up the torque. Gear reductions need to be significant because these small motors tend to spin at 3000 - 4000 rpm while the wheels spin at closer to 100 - 300 rpm.

So you need at least a 10 to 1 geardown somehow...