This is a simple go kart that I built using only reused materials left over from other projects. It is fun, easy, and can be painted and customized easily. Have fun!
Step 1: Materials
1 - 10 foot 2x4
3 - small non-swivel caster wheel
Carriage Bolt - 2 1/2" x 1/4"
Nut - 1/4"
Step 2: Prepare Wood
Start by marking your 10 foot 2x4 with a pencil. You will need the following lengths of wood: one 2 1/2 foot piece, three 1/2 foot pieces, and two 1 1/2 foot pieces. Mark out these cuts and then cut them with a chop saw. When you mark the wood you might want to account for the width of the saw blade.
Step 3: Drill
Start by choosing a drill bit slightly smaller in diameter than the carriage bolt you are using. Now drill a pilot hole in the center of both of the 1 1/2 foot pieces of 2x4. After you have drilled a pilot hole drill your first large hole. Keep increasing the size of the bit until you have the right hole for the bolt. The bolt should be able to slide freely but not all the way through. Now choose one piece of wood and counter-sink the hole for your bolt. This is where the nut will go. Also you will need to drill a hole in the center of the 2 1/2 foot length of 2x4 that is the same distance from the end as it is from either side. This should also fit the carriage bolt.
Step 4: Screws
Now you need to assemble the front and main frame of the kart. Start by aligning the two 1/2 foot pieces on the ends of one of the 1 1/2 foot pieces. Secure these using 2 1/2" construction screws. Now put the bolt through the other 1 1/2 foot piece and set it on top of the first assembly using the bolt to line the pieces up. Again, use construction screws to attach this piece. Also attach the last 1/2 foot piece to the end of the 2 1/2 foot piece that does not have a hole in it, this is where one of the wheels will mount.
Step 5: Sand
Now you need to sand the end of the 2 1/2 foot section that you drilled earlier. Sand a good ways down the piece because this is what will allow the kart to turn.
Step 6: Assemble
Now you need to assemble the pieces of the kart. Start by lining up the holes in the front piece and the 2 1/2 foot piece. Slide the carriage bolt through and put the nut on. Make sure the nut in on the side that is counter sunk. Now you are ready to add wheels!
Step 7: WHEELS!
Now you can attach wheels to the kart and finish it up. To do this use wood screws that will not penetrate the 2x4. Place your three wheels as shown in the picture, two in front and one on the extra piece in the back. Now drill the wood screws through two or more of the holes on the wheels and into the 2x4's. Congrats, you're done!
Step 8: Final Product
You should end up with something like this. Feel free to paint it or even add a seat if you want! Experiment with different hills and other areas. Always be safe while riding and where a helmet.