Help Making go kart out of Green Machine

[sideways]

wattage is sort of like "CC" ratings on an engine. (the size) but no actual comparison between electric and gas.

the more wattage, the more "juice"

the link you posted is for a motor found in electric scooter sized vehicles.


geared right, youd be able to hit 10-15 MAYBE depending on alot of factors. (just to say the approx. range)

it wont have good acceleration though unfortunately.


sacrifice speed for acceleration
sacrifice acceleration for speed

its all about the gear ratios.

Not really, Watts=power. 1000w (aka 1KW)= 1.34HP

However, for their power rating, electric engines feel much more powerful than petrol ones. This is due to their flat torque curve and relatively high torque out put.

You could get away with as little as 200w on that kart, it will fly with 800w. I wouldn't recommend any more than 500w with that cantilever steering and plastic wheels.

How fast do you want it to go?

 

[WillTheKing96]

Thanks again guys, great stuff! Sideways, I'm currently looking at a 24v 350w motor. According to your last post, that should be fine. What rough speeds can I expect from this if I use 2 12v in series and a ratio of 1:4 (not sure that ratio is right, about 11 teeth on the motor axle and 40 on the wheel sprocket) keep in mind the kart will be about 20kg and I am 50kg.

Thanks for the posts so far!

 

[WillTheKing96]

Progress!!!!!

Hey guys,
thought id post a quick update on the kart. Added steering and bolted seat on the ply. Also, secured the ply to the original frame.

Comments or questions welcome!

WillTheKing96

 

[B man]

so its a gravity kart. down hill only.

 

[WillTheKing96]

What makes it a gravity kart?

 

[baer]

I see some problems:
- there is not enough space for the motor, would it be mount on the wood?
- if I see correctly there there are no bearings on the rear shaft that would make problems with sprocket, especially with the narrow frame
- this kind of steering is ok for very low speed only, otherwise it would become difficult to control and dangerous.
- I wouldn't put on this setup more than 50W maximum 100W for safety and handling reason

 

[WillTheKing96]

Baer,
Yes, I planned on mounting the motor on the wood, and i have more wood if i dont have enough space. I dont really know what you mean by bearing on the rear shaft, there is a bearing on the inside of each rear wheel if thats what you mean. The steering is very easy for me to control so im not worried about that however the wheels do slide more than i want sometimes. Are there any ways i can rearrange the steering or wheels setup (really simple if possible, dont want too much extra work). But i see what you mean, and to be honest i would not want a smaller child to ride this as inexperience could cause loss of control. If the setup was only 50-100W, what speed could i expect from this, it seems fairly weak.

Thanks for the post,
WillTheKing96

 

[j.concepcion54321]

i think that you should just go with that 24 volt 350 watt motor. use 3 12 volt batteries to give it 36 volts and it should be pretty fast. i have one of those little motors and it says its rated for 2600 rpm. so yours should probably be the same. with 36 volts youd probably get around 3000 rpm. How big are your rear tires? which sprockets will you be using?? that way i can figure out your ratio, and tell you what speeds you will most likeley get.

 

[WillTheKing96]

A thought i just had,
it would be possible for me to remove the sliding front wheels on this kart and replace them with sturdier, grippier (is that a word??) tyres but when i remove the small plastic cap and attempt to remove the nut holding the wheel in place, the entire bolt moves with it. I know its a long shot but if i could remove these wheels and replace them the kart could become much safer

Cheers

 

[WillTheKing96]

J.concepcion
My rear wheels are 25cm dia. using 55 tooth sprocket on axle and 11 tooth on motor
Speed estimate would be great, please take into account the weight of me and kart (75kg)

 

[B man]

What makes it a gravity kart?

ahh an electric motor. thought it was just mean to be rid down hills

 

[studysession]

cool idea - my brother had one of the originals when we were kids. I had a big wheel and he had the green machine.

 

[j.concepcion54321]

the speed of the kart would be arpund 12-15mph. The calculator said 15 so i took weight into account and yeah i think that 12-15 is about right.

 

[WillTheKing96]

Just popped over to the shops to check out some stuff i need, found a battery that might work.
The "Century PS 1270" its 12v - 7Ah. Costs $38.99. Its around the right physical size (pretty small) for my kart, probs use two of them and the 24v 350w motor, add more if i need them.
Thoughts???