4WD hybrid electric go-kart (4 motors) - part 2.

[Buzzybee73]

Freakin' Genius, I'm an electrical engineer, and this is a far better way to build an off road kart. Plus, why bother with clutches and gears when you don't have to.

Couple of questions though...

Was your PWM cheap to build?

How did your alternator charge your batteries, how did you convert the voltage from what I'm guessing is 13.7v to 42vdc?

[NZAndy222]

@Buzzybee73

Making the PWM was cheep compared to buying one that could handle 400A and 1,000 amps spikes. But if I were to do it again I would be tempted to buy one. I programmed an Atmel chip to PWM a pile of FET's, my design is really an overkill, but there is no current limiter and that's good for 4WD vs. a golf cart like most are made for.

[NZAndy222]

@Buzzybee73

For the alternator I basically opened it up and cut the connections to the field winding controller then directly connected the field windings to another PWM control I made, works fine.

[NZAndy222]

@Buzzybee73

I can set alternator output voltage and it is variable. I did not even think that I would get 42v, but it works no problem and even takes surprisingly little field winding power.

[Buddhanz1]

Nice machine, well done.

[simcaP60fan]

how many miles, km, can you drive it?

[NZAndy222]

@simcaP60fan

I don't know, I will have to try that some time. most of the time we don't even bother starting the motor.

[4bmxbmx]

that is bad

[rch701]

you should get the Coolest dad award. I am thinking of making something similar but i am going to use 4 chainsaw engines and a computer to manage it all. It will be an engineering project for my university

[NZAndy222]

Goes 50Kmh, 36v on batteries at top speed, 40v with petrol motor charging.

Could go a lot faster, gearing is set low for off road driving, with the gearing it has now it will tow my car!

[callstermatron30]

how fast does it goe aprox?

and what voltage are those motors running at at top speed?

[NZAndy222]

The way it works is better than a differential. Think about it tis way: With more load motors uses more power, less load less power. so for example if 1 wheel comes off the ground it will spin but hardly uses any power, the power automatically goes to the motor under load, it's just the way it works so it's really simple, all 4 motors are connected in parallel. This seems an often ask question, but motors like this don't have fixed speed rather they “go with the flow"

[VampireGamer]

Does the lack of differentials make for strange handling?

[mycieran]

thats awsome good job

[Airsoftmaster123]

probably one of the coolest go karts i have ever seen. great job.

[dhymers]

Very nice, great work.

[Motorfordtoyota]

@ 0:59 I dont thing the suspension was working, I think the frame has some serious flex! It needs bigger tires, great Ideal though!

[NZAndy222]

@Motorfordtoyota,

There is zero flex in frame it is very solid, take another look, what you see flexing is part if the suspension, it has forward facing arms so is different from what you normally see, this gives room for your feet in a small go-kart.

Yep will need some bigger wheels, cheers.

[Motorfordtoyota]

@NZAndy222 oh, I was just joking, It looked like it was flexing a bit cause of the roughness on the hill, but jk! Very good set up tough!!

[SHUK0S]

awesome performance, well done,... music suits the video too :)

[212jonrouse]

total badass

[codylabam1]

post some specs

[NZAndy222]

@codylabam1

If you expand the description there are basic spec’s listed, if something is missing what do you want to know?

[codylabam1]

How much was that thing and did you make the suspension

[NZAndy222]

@codylabam1

I don't know how much it cost, got bits over a few years. The most expensive parts are the batteries, motors / sprockets etc… made the frame steel was cheep really. If your in the US that is a good place to by parts, much cheaper than NZ. I made the suspension and even the bearing holders, some parts are old traction arms form a car cut in two and welded for the suspension swing arms.  If I was to do it again I would make it lighter, the steel frame is very heavy.