A great hobby that can provide hours of fun and good family bonding is building a go-cart. One of the great parts of building your own go-cart is that you can do so fairly cheaply, and they aren't too difficult to build either. Make sure you have the proper supplies and safety equipment to ensure that everyone will be safe while designing and building the go-cart.
Purchase your tools, materials and safety gear. You will need to purchase square tubing, round steel barstock and a welder. You will also need a welding mask, an apron and gloves to protect you from the sparks of the welder.
Get plans for your go-cart. You will need some type of building plan in order to put it together. You can either design one yourself or you can find one online for free. One thing to keep in mind while you're designing your go-cart is the age of the driver. An adult driver will require more space in the driver's seat than a child.
Take off the engine from an old lawnmower. If you don't have an old unused lawnmower available, try and find one at a garage sale or flea market.
Cut the metal tubing and weld it together according to your design. This will be the frame of your new go-cart. Follow your design, and make sure the measurements are correct before you weld.
Put together the steering column. Use the 1/2-inch bar stock to make the linkage for your steering, and use the 3/4-inch bar stock to make the axles for your wheels. Drill cotter pins into the rear axle to help hold the assembly together.
Attach the drive pulley. Take your welder and weld the drive pulley straight to the axle, making sure it is aligned perfectly with the pulley on the lawnmower engine.
Weld a steel plate to the back frame to mount the engine on. Put your engine on the metal plate and make sure it lines up with the drive pulley. Bolt the engine in place.
Take the throttle cable and attach it to the hand cable.
Build your seats and floorboard out of pieces of plywood. Take the dimensions from your design to measure out just how long each piece of plywood needs to be before bolting them in place.