Junior Gokart

[Rambo]

Hi there Landuse...

I am planning small and Slow! go cart for my two sons... 2 and 4 years old... Also needs to be budget wise as I'm building 2!

The carts will be small! the kids only weigh in at 15kg!! But I know I'll be upgrading the carts later as they become bigger... this way I get them involved in some building and planning!

Engines and gearboxes could be recycled in future builds... Wheels ect too... Could you advise on where this could be sourced in South Africa? Sourcing Quad wheels should not be problematic... but any start up advice on an axle with a key for sprockets would be great? The moment anyone advertises racing gear it becomes way too expensive!

Later!

ps... they will be traversing grass and some gravel roads but nothing too hectic! Wheels should give me enough ground clearance!

 

[landuse]

Hi there Landuse...

I am planning small and Slow! go cart for my two sons... 2 and 4 years old... Also needs to be budget wise as I'm building 2!

The carts will be small! the kids only weigh in at 15kg!! But I know I'll be upgrading the carts later as they become bigger... this way I get them involved in some building and planning!

Engines and gearboxes could be recycled in future builds... Wheels ect too... Could you advise on where this could be sourced in South Africa? Sourcing Quad wheels should not be problematic... but any start up advice on an axle with a key for sprockets would be great? The moment anyone advertises racing gear it becomes way too expensive!

Later!

ps... they will be traversing grass and some gravel roads but nothing too hectic! Wheels should give me enough ground clearance!

I just bought a 1m 1" diameter axle, and it only cost me R75. You could probably get a 3/4" (or 20cm) axle for cheaper. I got it from an engineering shop in town. Steel merchants normally want to sell 6m lengths, so you need to ask elsewhere. You could ask them to cut the keyways as well when you get it. You will then have to get someone who can machine a keyway into it for you. Fo wheels, you can source from quads. You get those tiny quads that are for small kids. Their wheels work pretty well.

Engines would be pretty expensive. If you are buying new, you will be paying over R1500 per engine. Look on gumtree all the time. You can also try places like Adendorfs and ask if they have any reject pressure washers that you could get the engines off of.

Steel is also pretty cheap. I bought a 6m length of 25mm X 25mm X 2mm square tubing a couple of weeks ago, and it only cost me R130. I also frequent the scrap dealers to see what they have. Thinks like splate steel for engine mounts can be found there pretty easily.

Bearing hangers will probably have to be made. The axle bearings that attach to the hangers can just be pillow block bearings (look at pic).

You could also use mechanical brakes off those mini quads. Clutches can be bought at the places I linked earlier, or you can source from overseas. Have a look at this thread regarding clutches. I mailed the guy and they were very reasonable.

For gearing, I would gear the karts at 12:1 or 15:1. This means that you will have a low top speed, but a lot of torque. To attain this gear ratio, you will probably have to use a jackshaft. It will be used for compound gear reduction. If you were using just the clutch sprocket and axle sprocket, the axle sprocket would have to have something like 150 teeth, which would be scraping a huge hole in the ground due to not enough clearance. Look at pic for jackshaft example. That one is on a minibike, but you would have the same setup for a kart.

 

[OzFab]

Sorry Paul but, they're not pillow blocks, they're 2 bolt cast flanges (as opposed to pressed flanges). This

is a pillow block...

A small 2 stroke engine (like a pocket bike engine) would probably be enough to power a small kart, you don't want too much torque; just a thought...

 

[landuse]

Thanks. I just call all those bearings pillow block bearings.

 

[Rambo]

Thank man... I will approach a local engineering shop!

Is the keyway standard?

 

[mckutzy]

It is standard in relation to the shaft it is milled into.

 

[OzFab]

It may be an idea to get the hubs before the axle is machined; the hubs will have keyways in them already so you know what size keyway you need in the axle...