I've been searching for this for like 2hrs straight now.......

We are planning to make a small trike say the added weight of two people and frame is abt 200Kg.... Will a 500w dc motor suffice????????? Or how mch torque will it need to move??????? Pls help me out.....

 

Depends upon how fast you want the trike to move.

 

Depends upon how fast you want the trike to move.

Well about 40km/hr

 

Ofcourse you can get the trike to move! but with only 500 watts you will need quite abit of
gear reduction. Nevertheless I doubt you will make anything more than 10-20km/h and that's on a straight road

 

Ofcourse you can get the trike to move! but with only 500 watts you will need quite abit of
gear reduction. Nevertheless I doubt you will make anything more than 10-20km/h and that's on a straight road

Thanks a lot!!!!!! I'll be using 1kw motor......
How does varying the voltage take effect on it???????
say will a 48v lead acid battery work?????

 

Apart from '1kW' we know nothing about your motor so can't answer those questions.

 

On level ground the principal sources of drag are wind resistance, tire rolling resistance, then everything else (bearings, power transfer, etc.), in that order. Air drag goes up roughly with the square of speed, and that will determine your top end speed.

Acceleration or speed up a hill is limited by simple physics, and you can get a decent estimate by just ignoring wind resistance.

It takes a fair amount of power to raise 200kgs up an incline; about 54 watt-hours for an elevation increase of 100m.

 

2 people is already close to 200kg. The trike frame with batteries, motor, steering, 3 wheels etc will be pretty heavy too. Budget for maybe 350kg total.

500W is totally inadequate for that size vehicle. Even a 1kW motor will give pretty poor performance, and you can forget 40mph. You may get a "fast jogging" speed 10-12mph.

 

Most likely your gonna need a motor larger than 10kW, probably closer to the power of a small car engine ie 50-100kW.

 

Most likely your gonna need a motor larger than 10kW, probably closer to the power of a small car engine ie 50-100kW.

That seems a little excessive. A car with 50kW engine usually weighs around 1200kg and gets 0-100km/h in about 15 seconds. I think that 10kW motor will still be overkill for a two-person trike.

 

By law, my e-trike is limited to a 500W motor and a speed of 32km/h = 20mph.

You notice the lack of power on acceleration and going up an incline. Otherwise it runs well on level road.

 

For two people you probably want at least 1-2 Kw for anything decent , otherwise you will have have alot of gear reduction which will lead to low speeds.

As mentioned above , you need to know what voltage the motor operates at and I would suggest operating it with PWM .

The less KV* the motor has the better in your case because the less gear reduction hardware you will need.

*KV is a rating of a motor which tells you how many rotations the motor gives per volt supplied .
For example if you have a motor which has 250KV that means that With 10 volts it will run at 2500rpm

 

By law, my e-trike is limited to a 500W motor and a speed of 32km/h = 20mph.

You notice the lack of power on acceleration and going up an incline. Otherwise it runs well on level road.

I believe the law limits the rear wheel (drive wheel) power of a vehicle. So you are allowed no more than 500W drive power at the rear wheels.

That allows you to use a motor much larger than 500W (regardless of what most people think) provided you limit the electrical power into the motor to an amount that ensures no more than 500W appears at the drive wheels.

So if your motor efficiency is 75%, and your gearing/chain/bearings etc runs about 85%, you can legally input about 500/0.75/0.85 = 784W into a 1kW or 2kW motor at ANY speed (even from a standstill), which can make for a very nicely accelerating electric vehicle.