Instructions for Building a Small Teeter-Totter in 3rd Grade

The Central Support Unit

• 1

  Prepare and assemble the central support unit. Drill holes in the four 1.5- by 2.5-inch lumber; each piece should have three 9/16-inch holes. Drill the first hole 2 3/8 inches (60 mm) from the top of the wood. Drill the second hole 3 inches (75 mm) from the first hole, and the third hole 5 3/8 inches (135 mm) from the bottom of the wood. Drill one 9/16-inch hole at each end of the 1.5- by 3.5-inch lumber. Drill holes at each corresponding end of this piece of wood. Leave about a 1/2 inch at each end before drilling the hole. This piece will serve as a spacer between the other wood pieces.

• 2

  Place the spacer lengthwise in between the four pieces of wood (two on each side) with the end of the two drilled holes facing upward, making the third drilled holes meet with the holes drilled in the spacer. Connect the spacer and other wood pieces by attaching a carriage bolt through each end of the third drilled hole. The central support unit is now assembled.

• 3

  Prepare the bottom of the used tire for the concrete by laying thin wood pieces across the inside of the tire, with the tire laying flat on the ground.

• 4

  Mix gravel, cement and sand for the tire filling in the wheel barrow before adding water.

• 5

  Add about a half bucket of water. Add water a little at a time, stirring while adding, until the mix is uniform with good consistency.

• 6

  Shovel the wet mixture into the inside of the tire. Only add a couple of inches at the bottom and try to get most of mixture into the rim of the tire.

• 7

  Put the central support unit into the base of the tire. Wriggle the support unit if needed to make sure it is burrowed well into the cement mix. Add more of the cement mixture up to the carriage bolts. This will top the tire off. Make sure the cement is completely inside the rim of the tire.

• 8

  Place the long piece of wood on the front of the tire and use the large set square to make sure the central support unit is set horizontally correct (also called checking for a square alignment). Repeat this same measurement on the side of the tire. If adjustments need to be made, perform them at this time.

The Teeter-totter Plank

• 9

  Measure and find the middle of the 10-foot-long teeter-totter plank, and draw a square line (dotted line) in the center of the teeter-totter plank using the set square.

• 10

  Draw two more lines on either side of the square line using the set square. The two lines should be the same distance apart.

• 11

  Position the water pipe or pivot bar in the marked area.

• 12

  Fasten the pivot bar to the middle of the plank with the pipe saddle clips. If needed, place some guide nails when preparing the measurements for the pivot bar. The nails hold the pivot bar in place until it is fastened to the teeter-totter plank. The guidelines should be nailed slighting into the wood at the outside marking lines. Nail two on one side and one on the opposite side in the middle. Remove the guidelines after fastening the saddle clips.

• 13

  Choose the height for the plank. The two holes drilled at the top of the support unit allow for two different heights. Place the carriage bolts in your pre-drilled holes of choice.

• 14

  Place the teeter-totter plank in the central support unit with the pivot-bar side going down into the support unit. Lower the plank until the ends of the pivot bar rest snugly on the carriage bolts between the slots of the central support unit. The teeter-totter is now ready for hours of recess fun.