Off-road cart with joystick control

[superamp]

Hi

I am new and its great to be here.

I am building a cart for my 4yr old son. Power is from two 900w motors each on a seperate swing arm (back wheels) with independent suspension all round.

Instead of a steering wheel and pedals, all motion is directed by a joystick acting thru a dual motor contoler.

These pictures show progress so far.

Cheers

 

[brickbug]

ummmmm , do you work at NASA or something? thats a little unfair for the rest of us...lol
really tho,wow. lucky boy

 

[wingnut]

I'm not following. Are you talking about differential steering like a skid-steer or a tank or are you going to drive the steering with a servo?

The drive system is interesting. How are the motors coupled to the wheels? Looks like the motor axis is perpendicular to the axis of the wheels. Do they have some kind of integrated gearbox with a 90 degree output? What kind of gear reduction are you working with?

 

[superamp]

Hi

Yes differential steering on the back wheels and a server to operate the steering rack in the front.

The motors spin at 2600rpm and we have used 10:1 reduction gearboxes with 90 degree outputs. A shaft and a nylon coupler connects the motor to the gearbox.

We reckon the top speed will be about 12mph.

 

[Chuechco]

1,8kW equals about 2,4hp. Don't you think this is a little bit overkill for a 4 year old?

 

[everblade]

amazing! I've always wanted an electric kart, but I'm stuck with gas for now. You outta have tons of low end torque. 12 MPH is plenty fast for a 4 year olds off road toy.

 

[superamp]

Power & safety

Hi

Thanks for your concern for my young one and I agree in principle but our situation is different.

My son uses an electric wheelchair to get around. The problem is that the chair does not do well on the beach or at camp sites or river beds.

I looked at buying him an off-road wheelchair but they were all too narow and top heavy and I was worried that he would be badly injured if the chair rolled over.

I couldn't find any machine that would suit his needs so together with a friend of mine we set about building a low-seated wheelchair/quad bike/go-kart that would function primarily as a transport device over the weekends.

From the beginning our goal was for the car to look cool, store-bought and it had to last him a lifetime.We also wanted a crawler not a speedster so we geared it for torque.

With this in mind we designed the car around a full grown man and we made the frame out of thin-walled stainless steel and we specified the strongest scooter motors that we could find.

Because of my boy's special needs we have had to be very safety concious. The roll bar was decided upon from the begining, then we got him a big frame aluminium racing seat from Canada that we padded out to contour his body and we fitted a neoprene waistcoat to the seat to keep him upright. A fourpoint safety harness is on the way. He is good with a joystick but he can get quite wild so I will also have a knob on the dash that will limit his top speed and I can take control of the car via an RC transmitter at any time. I must say I am still worried though and we will have to take things slowly.

The next phase is to mould some body parts and to start with the electrics. I will post pics from time to time.

Cheers and good luck

 

[wkearney99]

Wow, sounds like a great idea. Good luck with it, your boy's lucky to have a Dad that handy.

 

[superamp]

Hi wkearney99

Thanks for the good wishes. The handy guy is actually a long time friend of mine (Deon) who is doing the heavy lifting.

 

[Doc Sprocket]

Hot dam, you're all over that! Are you doing the welding/fabrication yourself? I can't even imagine how you achieved that wild, futuristic elliptical shape. Well done! The technology you are employing is impressive, too. For a kid that's got the deck stacked against him, he sure is gonna be the envy of all the other (able) kids. Nice job, sir!

 

[superamp]

Hi toystory

Thanks for the kind words and yes we are doing all of the fabrication ourselves apart from the tube bending, this we subbed out to an engineering firm. Inspiration for the shape came from the Arial Atom.

We are busy with a nose cone and the mudguards. Attached is a vacuum forming mould I made yesterday for the mudguards. (We do vac forming at work). The mudguards will be formed out of 3mm black ABS plastic and then sprayed gloss black.

Cheers

 

[Doc Sprocket]

Wow- You win!

 

[huklebuk]

Are there any new updates? This is a fantastic project. I'm very interested to see how this turns out.

You sir are a good man for going the extra mile to make it not only functional, but to look awesome.

 

[landuse]

Hey superamp, where did you get those motors, and how much were they? Did you get them here in SA? Nice build by the way....

 

[superamp]

Scarab progress

Hi Huklebuk

Thanks for the interest.

We are making slow progress. This weekend I finished making a fibreglass mould for the nose cone. The cone hides the suspension turret and houses the RC receiver and the actuator for the steering rack. I am going to install the gauge from the battery monitoring system into the part of the cone that faces the driver.

I will post pics.

 

[superamp]

Hi Landuse

I got the motors from Monster Scooter Parts in the US. They cost me $125 each in Feb this year and about $75 shipping and then R400 for customs. I checked recently and the unit price is now over $230 Glad I bought when I did. Nice to see someone from SA on the forum!

Cheers

 

[landuse]

Hi Landuse

I got the motors from Monster Scooter Parts in the US. They cost me $125 each in Feb this year and about $75 shipping and then R400 for customs. I checked recently and the unit price is now over $230 Glad I bought when I did. Nice to see someone from SA on the forum!

Cheers

Thanks. I was hoping you maybe got them here. It really is a pain trying to find anything here go kart related that doesn't cost you an arm and a leg.

 

[superamp]

Latest picture

Hi

We are nearly finished wiring the beast and initial test drives show that the motors will easily carry the cart over rocks and logs and bumps of all kinds. Its getting exciting!

 

[HellSpawn]

Man this is some clean work. A+ in my book.

 

[souperman000]

It even has a nifty trunk platform for any camping or beach gear! those electric motors really left you a lot of space to play around with.