Homemade See Saw

Create a central support unit by connecting four pieces of one-and-a-half foot by two-and-a-half foot wood to the one-and-a-half-foot by three-and-a-half foot piece of wood (two pieces on each side of the wood at each end). Drill holes in each one-and-a-half foot by two-and-a-half foot board at five-and-three-eighths inches from the bottom and two-and-three-eighths and three inches from the top. Secure the bottom holes (connected to the one-and-a-half foot by three-and-a-half-foot board) with carriage bolts. Think of the overall structure as a three dimensional "H," with the first four boards forming the vertical lines on either side and the other board forming the horizontal line in between the others.

Line the tire with thin wood pieces on the bottom to cover the hole and to prevent the cement from leaking out the bottom. If you do not have wood, sheet plastic or sheet metal are acceptable alternatives.

Mix the cement. Fill a wheelbarrow with one part cement, two parts sand and three parts gravel. Mix it together using a spade or a shovel. Add half a bucket of water to the mixture. Mix with the spade or shovel until the mixture shares a consistency.

Add the wet concrete to the tire. Get as much as possible into the rims. Do not fill it all the way or you will have trouble getting the support unit in.

Insert the support unit (built in step one) into the wet concrete. Push it all the way down. Add more concrete mixture until the tire is completely filled.

Place a piece of wood across the tire and, using a set square, make sure that the front of the support unit is level. Repeat the process to ensure the side is level as well. Make any adjustments. Once satisfied, let the concrete set and solidify for two to three days.

Measure the one-and-half foot by seven-and-a-half foot wood and make a line across the center of the board for the pivot bar. Draw two equidistant lines on either side of the mark. They should be the same distance as the galvanized pipe.

Hammer three nails into the lines on either side of the center line. Place the pivot bar in between them, ensuring that it extends past the board equally on both sides. The nails will hold it in place while you secure it.

Fasten the pivot bar to the board using pipe saddle clips (or comparable fastening). Once the bar is secured, remove the guide nails.

Put two carriage bolts into the holes either three inches from the top, or two-and-three-eighths inches from the top (depending on height). Lower the seesaw plank (pivot bar down) into the center support until the plank rests on the carriage bolts. The seesaw is complete and ready to go.