chassis design and material

[rish]

hey i am building a gokart.. i know the basic design of a gokart but what i want to know is what are the basics one should know while designing it.. noreover what should be the chassis material considering my kart weighs around 100kgs

 

[OzFab]

100kg is a monster kart; are you building a kart or a buggy?

The main points are:
1. keep everything as low as possible; this prevents excessive roll
2. keep the weight balanced, both side to side & front to back; bad balance will affect pretty much everything
2a. if possible, mount the engine centred in front of the rear axle
3. wheelbase:track ratio should be around 4:3
4. If you're too uncomfortable, it won't be fun...

That's just what I can think of off the top of my head; others will throw in more...

 

[rish]

track width has to be 80% of the wheelbase.. this is a competition rule... we would like to build the kart as light as we could but everythngs weighs upto 100 kg

 

[OzFab]

That seems rather heavy, I don't think my kart weighs anywhere near that much...

Anyhoo, 1" round or square tube, thin wall (1.6mm, 1/16", 0.0625", 16 ga) will be fine

 

[rish]

see my minimum trackwidth has to be 50 inches and that makes wheelbase =40 inches atleast acc to rules..here is my weight division.. all are approx
chassis-12 kg
motor(bldc 48v 800w)= 9 kg
battery(48v 40ah)=30kg
brakes-7-10kg(disc)
steering-7-8 kg
solar panel(coz we are making hybrid)-5-7 kg
tyres-20 kg

 

[mckutzy]

Anyhoo, 1" round or square tube, thin wall (1.6mm, 1/16", 0.0625", 16 ga) will be fine

There fixed that for you, would have weighed more than 100kg for sure...

 

[OzFab]

What a difference a 0 makes, thanks

see my minimum trackwidth has to be 50 inches and that makes wheelbase =40 inches atleast acc to rules..

Are you sure you don't have that around the wrong way? Track shouldn't be more than wheelbase...

here is my weight division.. all are approx
chassis-12 kg
motor(bldc 48v 800w)= 9 kg
battery(48v 40ah)=30kg
brakes-7-10kg(disc)
steering-7-8 kg
solar panel(coz we are making hybrid)-5-7 kg
tyres-20 kg

Well, there's your problem; you didn't mention it was electric...

So, the weight of batteries & motor sound about right but, you may be a bit over on a few things:
-brakes-7-10kg(disc): what are you using, truck brakes? Mine weigh about 2-3kg
-steering-7-8 kg:Again, heavy equipment or are you including the front wheels?

 

[rish]

yeah sorry my fault there... wheelbse is 50 inches and trackwidth is 40 inches... fabromann i have seen your kart and it has a rectangular chassis.. i wish to make a chassis of this kind

 

[James.Ait.2013]

This might help you.. its a free plan. so I hope i'm doing nothing illegal.

http://www.cutpriceracing.com.au/Docs/RaceKart_Plan.pdf

 

[THE INTERCEPTOR]

The Important Part is getting a 50:50 ratio in left:right segment.
The front:rearcan go upto 40:60.
Are u using Round or rectangular tubes?Mainly What's your current choice for material?Mild Steel/Stainless steel/something else?

 

[rish]

i intend to use round tubes and my material would be aisi1020..

 

[rish]

That seems rather heavy, I don't think my kart weighs anywhere near that much...

Anyhoo, 1" round or square tube, thin wall (1.6mm, 1/16", 0.0625", 16 ga) will be fine

can i get a brief calculation or logic as to how you calculated that it should be 16 gauge?

 

[mckutzy]

16ga is .0625" wall thickness.

 

[rish]

yeah that i know.. my question is how to know the outer dia of tubing and the gauge thickness of tubing/? any formulae?

 

[mckutzy]

Pick an OD, then pick a thickness. It is manufactured in many styles, should be available from dealers almost anywhere.

Where are you located, fill in your profile so we can help you better.

 

[rish]

i am located in delhi india.... od means?? i intend to make my own chassis and not buy it from a dealer.. have to make a kart for a competition

 

[landuse]

i am located in delhi india.... od means?? i intend to make my own chassis and not buy it from a dealer.. have to make a kart for a competition

OD = outer diameter

 

[mckutzy]

Ok, good. There is a few Indian folks who post on here.
You might be able to buy/trade/barter steel from a scrap or metal dealer for what you need.
Depending on your budget, if you buy the metal at a scrap dealer, look for some motorcycle or scooter parts, like brakes and tires/wheels.

Also what kind of tools/ welder do you have available?

 

[rish]

i have tig welding available.. my question still stands
1) HOW TO CALCULATE OD FOR KART FRAME
2)HOW TO CALCULATE GAUGE for FRAME
i need formulaes so that i can verify that a given material with given specification can take the load of the kart

 

[OzFab]

There's no magic formula, the only thing to remember is thicker wall material will make the frame heavier but, not necessarily stronger.

It all comes down to what design you use & availability of materials as to what you use; if you have a design in mind, post it or a sketch & we'll help you decide...