See saw scales are a simple way to measure the weight of a small object. Like a see saw, the scales balance out when the weight on either side is even. On one side of the see saw scales, you put the object to be weighed. On the other side, add weights of a set value. When the sides balance, add up the known weights.
Cut a rectangular piece of lumbar to size. For a small scale, a 2-foot long 2 x 4 will work well.
Drill a hole through the exact center of the board. Stick a piece of dowel through the wood and glue it in place. The dowel should extend 1.5 inches or so so on either side. This is your balance.
Screw an eye hook into each end of the balance. Make sure that they are the same size, and evenly placed.
Hang a small bucket from each eye hook. Use a length of chain or string to attach it. Make sure that you use the same length of chain on each side.
Cut identical grooves in the top of two boards. The grooves should be deep enough for the dowels to sit in without rolling out. These are your supports
Nail the two supports on to a base. Place them close enough so that the dowel can sit on both. If they do not stay parallel, nail a small piece of wood to both half way up. Set the dowel in the supports.