Chapter 25: Homemade tools and teaching materials
If this scale is made with plywood,
use sheet metal to reinforce the upper
corner. The weight should be between
1 and 2 kilograms. It can be made from
scrap metal or a piece of heavy pipe.
This scale is made with a coil spring
inside a bamboo tube. The spring
should be about 30 centimeters
long and squeeze to half its length
with a weight of 15 kilograms.
2 cm apart
wire or cord
How to make the scales accurate
To mark the scale accurately, you will need some standard weights.
Perhaps you can:
• borrow some weights from a merchant at the market.
• use a merchant’s scales to
make your own weights by
filling bags with sand.
• use 1-kilogram packages or cans of food.
To mark your scale
1. Hang a 1-kilogram weight on it.
2. Balance the movable weight.
3. Mark the spot with a small line and write a “1.”
4. Now add 1 more kilogram at
a time, rebalancing the
weight and making a mark
each time, until you have
6 or 7 marks on the scale.
A Book for Midwives (2010)