Go-karts using lawn tractor parts
#1
Go-karts using lawn tractor parts
Hi Everyone,
I've been working on a few designs for karts that use the drivetrain from a sears lawn tractor. Really any tractor will work, I just had an old sears on hand. The designs look like smaller versions of formula 1 and Lemans LMP cars. Unfortunately I haven't had enough time to build one of them. I'm using autocad for all the chassis layout and hand sketching the body designs. Does anyone know if 1" square tubing is good enough for a 450 lb. vehicle? I guess I could just add more supports if there's too much frame flex. Just wanted to see if there was any interest in the idea before wasted my time making a website to post my work.
Mike
I've been working on a few designs for karts that use the drivetrain from a sears lawn tractor. Really any tractor will work, I just had an old sears on hand. The designs look like smaller versions of formula 1 and Lemans LMP cars. Unfortunately I haven't had enough time to build one of them. I'm using autocad for all the chassis layout and hand sketching the body designs. Does anyone know if 1" square tubing is good enough for a 450 lb. vehicle? I guess I could just add more supports if there's too much frame flex. Just wanted to see if there was any interest in the idea before wasted my time making a website to post my work.
Mike
#2
If 1” tube is laid ou and welded right it should be fine, if the cart will be used mostly on flat surfaces. But, if the vehicle is going to see any rough off road use you would need to use bigger.
#4
Group Moderator
If the tubing is good enough will depend on your design. Many airplanes have been built using tubing much smaller. It's all a matter of puting the strength where the load is.
#5
I know that most kart frames are built from 32mm Cro-Moly tubing, but they are designed to flex so that it can actually turn effectively. Mine will be mild steel and have much more tubing. I'll try to post some screenshots from AutoCAD so that you can make suggestions for improvement.
#6
Here's a picture of one of the ideas I've been working on.
www.umr.edu/~mshn88
Would 1/8 inch steel be strong enough for the motor mounting plate? I think lawn tractor frames might be made of something a little thinner. Thanks for the input.
Michael
www.umr.edu/~mshn88
Would 1/8 inch steel be strong enough for the motor mounting plate? I think lawn tractor frames might be made of something a little thinner. Thanks for the input.
Michael
#7
Group Moderator
If you are using a motor less than 10 hp I would think that 1/8" thick steel plate is more than enough for a motor mount.
My kart weighs about 120 pounds with everything: motor, fuel tank, body, seat, wheels & tires... so you can get an idea how much metal was used. Most of the core of the main frame is 1 1/4" tubing while the rest of the frame (foot well cage, side/nerf bars, bumper) is 1/2" tubing.
Don't make your body too complex unless you just want it to look cool. The body in your drawing looks pretty complex and possibly heavy. You will not get much benefit (other than looks) untill you get over 40 mph.
It also looks like you have the driver and the engine in the center. Most karts put the engine beside the driver to keep the wheelbase shorter. In oval track (turning to the left only) the driver lays in the kart on an angle with feet centered in the nose and head near the left rear tire and the engine is beside the drivers right shoulder. Road course karts have the driver more centered and sitting more upright but still put the engine almost beside the driver.
If you install a roll bar you should plan on a full cage and five strap seat belt/harness system. Some racing karts have full cages and harnesses (they even strap in your arms) but most do not have anything. I guess the theory is that if you have a roll cage you need to secure the driver in the cage where they can be properly protected, most of the racing karts do not bother with just a roll bar. They do a full cage or nothing. The idea with no roll cage is that the driver is free to come out of the kart and separate from the wreckage.
My kart weighs about 120 pounds with everything: motor, fuel tank, body, seat, wheels & tires... so you can get an idea how much metal was used. Most of the core of the main frame is 1 1/4" tubing while the rest of the frame (foot well cage, side/nerf bars, bumper) is 1/2" tubing.
Don't make your body too complex unless you just want it to look cool. The body in your drawing looks pretty complex and possibly heavy. You will not get much benefit (other than looks) untill you get over 40 mph.
It also looks like you have the driver and the engine in the center. Most karts put the engine beside the driver to keep the wheelbase shorter. In oval track (turning to the left only) the driver lays in the kart on an angle with feet centered in the nose and head near the left rear tire and the engine is beside the drivers right shoulder. Road course karts have the driver more centered and sitting more upright but still put the engine almost beside the driver.
If you install a roll bar you should plan on a full cage and five strap seat belt/harness system. Some racing karts have full cages and harnesses (they even strap in your arms) but most do not have anything. I guess the theory is that if you have a roll cage you need to secure the driver in the cage where they can be properly protected, most of the racing karts do not bother with just a roll bar. They do a full cage or nothing. The idea with no roll cage is that the driver is free to come out of the kart and separate from the wreckage.