D&D Motor Under Performing

[Bmatlock00]

Wow, I guess the motor I had on it before that did 30mph would have pushed a cart with stock wheels over 40mph.

[scottyb]

Curious, what happened to the 30 mph motor you were running before?

[Bmatlock00]

I loaded up 4 people on the cart and 8 people on a 5x10 trailer behind the cart for Halloween and burnt it up. I knew better but did it anyways....

[scottyb]

The motor you listed from D&D is advertised at 18 mph.
22mph on 48 & with big tires does not sound like it is performing any less than advertised.

[Bmatlock00]

Originally Posted by scottyb

The motor you listed from D&D is advertised at 18 mph.
22mph on 48 & with big tires does not sound like it is performing any less than advertised.

I guess after seeing bigger tires = more speed on here so much I was expecting too much.

[JohnnieB]

Originally Posted by scottyb

The motor you listed from D&D is advertised at 18 mph.
22mph on 48 & with big tires does not sound like it is performing any less than advertised.

I'm guessing, but I suspect the 18MPH @ 36V is on 18" tires.

Theoretically, upping the tire height to 23" will up the speed by 28% to 23MPH and then upping the pack voltage to 48V will up the speed by 33% to 30.6MPH, but the torque of the high-speed motor is 10% less than stock and the torque loss by the change in final drive ratio due to tire height is 22%, which knocks down the speed to 21.5 MPH mathematically.

So getting 22MPH for the set-up indicates the motor is actually performing better than the theoretical model, rather than under-performing.

There are a ton of variables, but combining a high-speed final drive ratio (taller tires or numerically lower gear ratio in differential) and a high-speed motor doesn't necessarily mean a higher top speed for the cart.

[scottyb]

Originally Posted by Bmatlock00

I guess after seeing bigger tires = more speed on here so much I was expecting too much.

Bigger diameter tires increase the final gear ratio. This can add more top end speed if the motor is not adversely effected by the additional load or the amperage delivery fails to meet the demand. Remember the wider and softer a tire it is the more energy required to turn it.

[Bmatlock00]

Thanks for your replies guys, 22mph is plenty fast enough. I just wanted to make sure everything is working like it should.

[TrickCart]

Originally Posted by Bmatlock00

I loaded up 4 people on the cart and 8 people on a 5x10 trailer behind the cart for Halloween and burnt it up. I knew better but did it anyways....

well ****... this is exactly what i do with my stock 36v TXT.. i never even considered burning up the motor :/

[scottyb]

Lots of people never check the oil in the car and they don't think about blowing up the motor either, I'm just saying again... the stock motor is 2 - 3 hp designed to push 2 people on 18 inch tires 300 yards up a groomed path and rest. Anything else we do with them is going to create more stress and require more power.



Hi speed motors suffer when put to work like a high torque motor. Specialty motors loose some of the versatility you see in the stock motors.