# Electric gokart



## Thalass (Dec 28, 2007)

Hey folks. I've wanted to do an electric conversion for many years, and finally things are starting to look like it might be possible for me to do. I thought I'd start with something small, like a gokart for my kids. 

I found some mention on a gokart forum of using a 1kW motor for a kid's kart, but even as an EV enthusiast it doesn't seem like something that physically small could put out enough power to make something of that weight go. 

But assuming it will work, I've been looking through hobbyking.com and have found heaps of motors in the 1-5kW range. I was thinking of using a microcontroller to convert the potentiometer input to an RC-style pulse train for the motor controllers that are usually used for this kind of motor, and lipo cells. 


So my question is this: Does this sound sane? Has it been done before? All my previous investigation of EV conversions has been motorcycles and cars, but a Warp9 would be overkill for this!


----------



## ken will (Dec 19, 2009)

An approximation is 750 watts = 1 HP. so a 1kw motor is about 1.3 hp

One problem with HobbyKing motors is that they spin at 10,000 to 15,000 rpm!


----------



## Thalass (Dec 28, 2007)

I don't know imperial measurements, so I don't know how big the horse you're talking about is.  

I didn't think about the high RPM of those motors, though. I suppose a gearbox would probably make things too difficult. Might be better to just use an 0709 with a simple chain reduction. 5:1 is easier than 20:1 haha


----------



## Sunking (Aug 10, 2009)

Thalass said:


> But assuming it will work, I've been looking through hobbyking.com and have found heaps of motors in the 1-5kW range.


No No No. Those motors are not designed to do what you want to do. You would burn it up on the first run. They are like men and can only go for a few minutes. Seriously they will overheat in just a few minutes and burn up. They are low torque and high RPM motors. They burn up almost immediately with locked rotor current which is what you have when you start. The low Torque at 0 to a few hundred RPM is extremely low and the motor would not be able to accelerate fast enough before burning up trying with your kids pedal to the medal.

The real issue is the motors are only designed to be ran 5 to 10 minutes at most. Typically 5 minutes or less. Any longer and they severely over heat. Heck they over heat when used as intended. They are pushed well beyond their limits and thus why they are toys. I fly RC planes and we use LiPo packs rated for 25 to 100 C. The motors typically draw 20 to 50C from their intended battery pack. 20C discharge time is 3 minutes. Sure you could put in a battery that last 30 minutes, but the motor would melt down in 10 minutes if that long.


----------



## samwichse (Jan 28, 2012)

As a counterpoint, Astro Flight motors are THE goto for high performance ebikes... which doesn't seem too far off in performance envelope from a go-kart.

https://www.electricbike.com/astro/


----------



## Thalass (Dec 28, 2007)

Ah those Astro bikes look pretty good. Thanks for that. 

Sunking you make a good point. I was a bit sceptical when I read about using these motors, which is why I asked here. My kids are only little, so the performance requirement at this stage is pretty low. As a comparison my son (he's 4) has a little plastic 6v car with plastic wheels that spin at the slightest bit of grass or something. So it can only get better from there, as long as the wife approves the safety of it.


----------



## Sunking (Aug 10, 2009)

Thalass said:


> Sunking you make a good point. I was a bit sceptical when I read about using these motors, which is why I asked here.


Hope it helped. I am not saying it has not been done before as I am sure it has. Just saying it is not the right motor for the application. 

Hobbyking is popular with Euro RC modelers, but the equipment like batteries and motors quality is pretty low. But I would not even attempt it with some of the higher quality manufactures as it is just not designed to do that.

The ebike and motorcycle electric motors are not a bad idea, but can be expensive for what you get. Like EV motors is a very niche market which means real expensive.

But there is another market with tons of motors and controller possibilities. Even a lot of used and salvaged parts. Figure it out yet?

GOLF CART.

Tons of motor and controller options from hundreds of distributors and manufactures. Size is perfect for a Go Cart ranging from 2 to 16 hp and 24 to 72 volts. Even the transmission, wheels, suspensions, you name it. Pay as little as you want to as much as you want. I suggest either find a large dealer of EZGO with a grave yard of carts and find a cheap motor and transaxle to salvage. Or hunt around Craigslist for an old fixer upper for parts. Even a new 2 hp DC motor is pretty cheap. 

There are also very easy to SPEED LIMIT. 

That is my Shtick. I have heavily modified golf cart. Some call it a Racing Golf Cart, others a NEV, some a golf cart because it is all those things. I found a good frame, body, and differential cheap and built my cart from that.


----------



## Thalass (Dec 28, 2007)

Huh. I suppose I think "golf cart" and think "slow", so never considered them for a motorcycle or car. But for a gokart it would probably be perfect.


----------



## Sunking (Aug 10, 2009)

Thalass said:


> Huh. I suppose I think "golf cart" and think "slow", so never considered them for a motorcycle or car.


You need an attitude adjustment upside the head with a 2 x 4 

How about 118 mph @ 12.24 second 1/4 mile. Stock golf cart with Plum Quick DC motor. Click here for video. For some reason this site will not allow Videos. The Video button does not work.

Stock Golf Carts are speed limited by the factory. They ae capable of much faster speeds with just some simple modifications like replacing the speed controller that does not have a sped limit built in. Todays golf carts are limited to 19 mph. If you have the controller programmer remove the RPM limit and they go 25 to 30 mph. Change the tire sizes and they go faster. Change differential ratio, larger tires, and controller they go even faster. Change motor, controller, battery types, high speed differential to 8:1 ratio, and 22 inch tires like mine and they go 60 mph. Go high performance motor and controller they go 118 mph. 

A stock golf cart motor has more than enough power for a Go-Cart. A stock series wound 2.2 Kw motor operating at 48 volts with a cheap PWM 175 amp factory controller will get a light weight Go Cart to 40 mph easily burning rubber on pavement. Enough you want to make sure your kids have good medical and life insurance. All for a lot less money than an Ebike or motorcycle motors and controller will cost you. You can use the money you save for insurance. 

You got one part right though. Golf Cart motors would not be usable in a car except for 2 or 3 I can think of. HPEV AC9 which I use in my golf cart. But that is a $2800 motor and controller. You can do it for less than $400.


----------



## jvh22a (Jun 10, 2015)

im looking to do a similar project. but i know nothing about electrical stuff beside installing a head unit in a car and basic stuff. 

i've been searching youtube to see what kind of equipment is used but not getting any exact parts i would need. 

do you know any place i can just buy a pre made kit. i can do all the mounting/welding work etc. i just do not have a clue when it comes to electricity.


go kart is meant for my kids and me so i would like to be able to limit the speed and if reverse is an option, even better. 

i see my1020 motors, controllers, twist throttle on ebay for about $120 (36v 800w) will that be enough to get the kart going? is that something good to start off with? i dont want to speed to much if it is not really needed. im not racing, just going up and down my street with my kids.


----------

