Having trouble with E kart

[8ball_99]

Ok so I've read most if not all the threads in this forum on E karts.. My idea was to make a go kart electric for my son to replace his power wheels. power wheels is ok just has a small battery and he has worn the tires out in a few months..

Everyone on here always links to monster scooters or Tnc scooters, ect for motors. Well I got a 500 watt 24V motor and controller. With a 72 tooth sprocket on the axle and 11 Tooth on the motor The kart didn't have much power.. Once it got going on pavement it would go pretty fast, But would not even start in grass.. So I figured the kart was to heavy for it.. So I ordered a second 500 watt 24v motor and controller. I also ordered two 13 tooth sprockets for the motors.. 72 tooth is the biggest I could find for the axle. Even with both motors and the larger motor sprocket the kart still doesn't have any power.. It will go pretty fas once it gets going but in grass or on a hill it doesn't do much. Not sure where to go from here... I don't want the kart to go fast but I do want it to have power for hills and grass.

 

[anderkart]

You'd get better acceleration (for driving in the grass) with 11-tooth gears on the motors instead of those 13's.

72 tooth is the biggest I could find for the axle.

How tall are your rear tires?

 

[oscaryu1]

So you geared the motors up with bigger motor sprockets and expected more torque? Lol. Get a 36v controller and run a 36v setup. They DO make sprockets larger than 76 teeth, but they'd take some modification for them to fit.

Hell, it could be a bottlenecking controller. What controller are you using and what is the amperage its rated to put out?

 

[8ball_99]

Yeah I put the 11 tooth sprockets back on the motors... For what ever reason I was thinking the more teeth the better.. I forgot it works the other way with the sprocket on the motor. Not real use to messing with chains.. Me and my wife both have Polaris RZRs with CVTs.. So no go karts. I built this for my sons 4th birthday to replace his power wheels..

I'm going to keep looking for larger sprockets. 11 and 72 with these motors is not the right gearing I need.. Its to fast once it gets going and doesn't have enough power for off road.. The controllers I got are from the scooter place.. They are rated for 500 watt motors. I have one controller for each motor. I have not tried it since I added the second motor but I did hot wire the motor straight to the battery with a solenoid and really wasn't much difference as far as power.. The wires on the motor did get pretty hot though..

I do not want to overvolt the motors. If I wanted to go to 36 volt I would have just got 36 volt motors. I want 24v because I only want to run 2 batteries. You have to remember i'm shooting for something a little different then most on here.. I need a top speed of like 10mph...

I haven't worked on the cart since the other day. It will have to wait till after this weekend since we have a trip planed to go off roading. Once I get back I'm going to get this thing figured out... If anyone knows where to get a sprocket larger then 72 tooth for #25 chain and a 1" live axle let me know...

 

[oscaryu1]

Overvolting will get you that extra torque you need. Get the Currie 900W motors. 900W at 24v... I've been running them at 48v for a few months now with no side effects. In fact, I split one open and other than a bit of oxidation, it looks terrific!

Top speed of 24MPH with 12.5" tires and 11/90 gearing.

http://www.youtube.com/watch?v=txyDd3VvI9M

Plenty of torque for whatever needs 8)

 

[8ball_99]

I'm going to try and make due with the motors and controllers I have. I really think if I gear it lower it will probably do what I want. My son has a Stinger power wheels that works pretty well. It just doesn't have quite enough power, run time and the tires suck.

 

[dazarooney]

Keep us updated of on your progress, I'd like to know how you get on as this is something I'm considering doing it.

 

[8ball_99]

Will do. Right now I'm waiting on a 90 tooth sprocket to come in. Best I can figure that will give the cart a top speed of around 12 mph. I hope it gives it enough low end power. 90 tooth was the biggest I could find and it cost twice as much as any other sprocket.

 

[number 37]

^reported as spam

 

[Odonnellp24]

If youre looking for massive reduction then just use a jackshaft. That's just an intermediate shaft that allows for a double reduction so you can reduce your axle sprocket size and still achieve good reduction.