How to Make a Steelyard

Now that you know how it works and how to use it, why don't you try making your own steelyard? Here are simple instructions.

Materials needed:

• 1 small and 1 large strong and watertight shopping bag (make sure there are no leaks!)
• 1 unbendable meter stick or yardstick (or any strong stick over or at 1 yd/meter)
• Sand or water
• Saw
• Drill
• Thick string
• Marker or paint
• Scale

Procedure:

1. Draw a plan based on your knowledge of how it works.
2. Saw a slit about 1 cm from 1 side of the stick.
3. Put the large bag handle into the slit and let it rest.
4. Make another slit about 2 cm from the same end of the stick.
5. Tie a string into the slit and make a loop out of the untied part
6. Measure 1 kg of sand or water with the scale and pour it into the large shopping bag. Hold onto the stick or lay it down so that it's level.
7. Fill the small bag about four-fifths full with sand or water and hang it on the long section of the stick. That is your weight.
8. Pick up the steelyard by the piece of string. Move the weight until the stick is balanced.
9. Mark 1 kg on the spot in which the weight is hanging.
10. Take the sand out from the large bag and, holding on to the string, move the weight until the stick is balanced.
11. Mark 0 at the place where the weight is hanging.
12. Divide the space between into 4, 5, or 10 equal pieces. Mark.
13. Measure the distance between 0 and 1 kg. Mark 2 kg on that distance from 1 kg (opposite from 0).
14. Repeat steps 12 and 13 for 3 kg, 4 kg, 5 kg, etc until you reach the outermost edge.
15. If you want to make a steelyard that weighs heavier things, put another string about 1 cm from the short end. Move the bag to about 0.5 cm from the short end then repeat steps 2-14. .

You have now completed your steelyard.

Note: you can be flexible about the slit positions.