# accelerator for a go-kart, build by a 10 YO kid



## barcelona (Aug 11, 2012)

Hi all

I'm living in Barcelona in Europe, and have started 1 year ago a crazy project with my son (10 years old) : building himself an electric Go-kart. 

I say "crazy" because he has to follow 2 rules : 
- he has to do everything himself (screwing, sawing, wiring, painting, and even welding , his favorite one) , I just provide the materials
- we have to use ( and found!) only recycled materials, nothing new. 

But he is so motivated by the challenge , that , after hours and hours of working on it, he has nearly finished the project ( chassis with suspension, gear, seat, steering, brakes, batteries, engine, wheels..) 

But we are totally blocked now with the only missing point : the accelerator. We don't know where to buy it , or even more complex if needed, how to build one. 

The electric engine we had from an Electric Repair Workshop : 
- has a maximum voltage of 85v 
- is a DC one ( I mean continuous current)
- has 4 big cables to be connected 

We have on the other hand 6 x 12v battery to power it. 

That's all what we know :-( I don't have any knowledge about electricity or electronic, and have no idea of what we need. 

I post here , but perhaps I should have done it in the "controllers" part … in case of the "accelerator" I'm looking for is in reality a "controller", which I don't know. 

We are in the US right now for holidays during 3 weeks , so if anybody has an idea about where we could find this accelerator, it would be rally great . 

Best regards

Pol & Marc ( my son)


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## TEV (Nov 25, 2011)

Unfortunate you are missing a very important component: the " Controller "

The "accelerator" or "Pot Box "will have to match the controller.


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## Ziggythewiz (May 16, 2010)

you could probably recycle a controller and throttle from an old fork lift or golf cart.


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## PStechPaul (May 1, 2012)

It would be good to learn enough electronics to understand how a PWM control works. I'd suggest getting an electronic kit so you can actually build a PWM control. Here is one that might be useful"

http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_120539_-1
http://www.jameco.com/Jameco/Products/ProdDS/120539.pdf





 
Even better may be to get an Arduino development kit and add the motor control "shield":
http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_2121130_-1

Of course those are "new" and not recycled, but the idea is more to learn how PWM controllers work. For the actual project, you might be able to find an old treadmill which often has a big (2HP or so) DC motor and some sort of PWM controller. That should be plenty large enough for a go-cart.

For the accelerator, find a cable-operated type in a junk yard and rig up a spring-return connection to a rotary potentiometer. You might scrounge some parts from an old tape player or tuner.

I like your idea of using all recycled/junk parts. I'm doing that to some extent with my electric tractor project. These are very important survival skills which may be very valuable if and when the economic system collapses and we will need to dumpster-dive and be creative.

Good luck!


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## barcelona (Aug 11, 2012)

Ziggythewiz said:


> you could probably recycle a controller and throttle from an old fork lift or golf cart.


would you know by chance a place to found this here in the US (a specialist for spare parts of golf cart, o fork lift ) ? 

thank's and best regards

pol


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## barcelona (Aug 11, 2012)

PStechPaul said:


> It would be good to learn enough electronics to understand how a PWM control works. I'd suggest getting an electronic kit so you can actually build a PWM control. Here is one that might be useful"
> 
> http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_120539_-1
> http://www.jameco.com/Jameco/Products/ProdDS/120539.pdf
> ...


thank's for your post !

This part is a big challenge for me , but I agree it's definitively usefull for our project to understand it. If I didn't found a recycled solution , I'll probably go for the Arduino solution , with is also very educativ. 

To be sure I've understood correctly what you are saying : the arduino option will serve also for operating the go kart , not only for learning ? 


About the treadmill option : do you mean I've to forget the engine we've already for another one, coming from a treadmill ? or you mean I just have to take the PWM controller ? 


finally , about your final comment, you'v got the point : I realize with this Go-Cart project than my kid didn't koweven how to use a nut !

best regards

pol


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## Ziggythewiz (May 16, 2010)

barcelona said:


> would you know by chance a place to found this here in the US (a specialist for spare parts of golf cart, o fork lift ) ?


I haven't done it myself, but some here have. If you have any junk or scrap yards around you could check there.

Also, google 'forkenswift' for ideas.


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## PStechPaul (May 1, 2012)

The problem with treadmill motors and controllers is that they are generally 90-120 VDC. Here is a video of somebody who took one apart and is running the motor:





 
But these may be much more common and cheaper than a controller made for a lower voltage motor. A cordless electric drill might be a better source for the controller and also the trigger could be used for the throttle.





 
For the Arduino:





 
These should be considered just starting points. If you provide the information on your motor and batteries and gearing and expectations of acceleration and top speed, we can give more specific help. Mostly, you will probably need to use a larger transistor for a larger motor, but the basic control will be the same. If you use the Arduino, you can also play around with DTC by using a current sensor.

I use PICs for my projects. But I think there may be a larger base of young hobbyists for the Arduino.

Using a PIC:


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## McRat (Jul 10, 2012)

Do you have medical insurance?

Take a piece of wood, and put 6 bolts in it in an arc. First bolt is 12v, second is 24, third = 36, 48, 60, 72. Put a lever with a bolt in it with a BIG ground wire on it. Wire it so the first bolt sees one battery, the second sees 2 in series, the third - 3 in series.

Put a big spring on it so it "lifts" if it crashes.

Have fun!


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