Electric Go Kart

[vn7]

I am building an electric go kart using a DC brush motor of 3 HP and 1800 RPM.....wheel diameter is 11 inches and total weight (kart+driver) is 180 Kgs.
How do i find out the torque produced?
How do i find out the maximum speed?
I would like to know weather I should go in for a higher RPM motor or not and also which sprocket should I be using on the motor and on the axle to get the best acceleration and speed.

 

[Doc Sprocket]

I'm not an electric guy, but I can tell you that for the most part, calculating your theoretical top speed involves the same formulae and variables regardless of whether you use a motor or an engine.

 

[jman231994]

Going off a calculator the motor will put out 8.75 foot pounds of torque. It didnt give it in metric, and thats at 1800rpm. The motor will produce less and less as rpm reduces, power shouldnt change too much though as electric motors have a generally flat power curve.

I see weight as your major issue, top speed might end up limited by power availability

Personally I think its a test it and see what happens situation. Higher rpm though definitely wont hurt, it will allow you to use more conventional gearing

 

[vn7]

TORQUE - HP*5252/RPM = 3*5252/1800 = 8.7533 ft-lb

Look i am just a student and in urgent need of someone to cross check my calculations....lets say I plan to go with 3600 RPM instead of the original 1800 RPM then the NEW TORQUE = 4.3766 ft-lb.....now my question is HOW MUCH WEIGHT CAN I MOVE??
Number of teeth on clutch sprocket=12 and axle sprocket=60 i.e gear ratio= 5

 

[landuse]

TORQUE - HP*5252/RPM = 3*5252/1800 = 8.7533 ft-lb

Look i am just a student and in urgent need of someone to cross check my calculations....lets say I plan to go with 3600 RPM instead of the original 1800 RPM then the NEW TORQUE = 4.3766 ft-lb.....now my question is HOW MUCH WEIGHT CAN I MOVE??
Number of teeth on clutch sprocket=12 and axle sprocket=60 i.e gear ratio= 5

I really cannot help you with your calculations, but even for an electric kart, a 5:1 ratio is a bit tall. I would start off with a 6:1 ratio rather