The materials you will need are:
One hacksaw blade which can be either of the two types shown in Section D. The length can be 25 or 30 cm.
Four straight pieces of wood from tree branches. Length: larger than 36 cm but less than 38 cm Circumference: between 8 and 10 cm one of these pieces is split along its length into two equal pieces.
One piece of string which measures more than 200 cm but less than 250 cm
Two nails, 4 cm long
Two nails, 6/½ cm long
A heavy knife can also be used. (Sometimes called a machete, panga, bolo in various countries.)
Making the Saw
First, a hole is made near each end of the two split pieces of wood using the drill. Drill the holes wide enough for a 6/½ cm nail to be hammered through without splitting the wood. The holes should be 3 to 5 cm from the ends of the sticks. This procedure is shown in Diagram A. Next, drill one hole in each of two of the other pieces of wood. Each hole is 12 to 15 cm from one end of the wood. This procedure is shown in Diagram B.
The four pieces of wood are then joined together using 6/½ cm nails as shown in Diagram C. The ends of the nails are bent using a hammer. Do this carefully so that the pieces of wood do not split.
A cut is now made in the ends of the two pieces of wood where the blade is to be attached. The blade should be able to fit into the two cuts without it becoming bent.
A hole is now made near each end of the pieces of wood where the cuts have just been made. Each hole is placed so that the nail will go through both the hole in the wood and the hole in the end of the blade. Use a hammer to bend the nails which hold the blade. Do this carefully to avoid damaging the wood or the blade.
Notches are then made between 3 and 5 cm from the ends of the pieces of wood where the string is to be attached.
Attach the string by wrapping it around the two pieces of wood at the notches. The string should be wrapped 2 or 3 times and then tied together. Put the last piece of wood through the string and turn until the string twists enough to tighten the blade.
The saw is now ready to use.
You can check the tightness of the blade in this kind of saw by the tightness or looseness of the strings. If a pupil has tightened his or her saw too much and the string has broken so that most of it is lost, it may no longer be possible to tighten the blade properly. Sometimes pupils will attempt to use their saws with no string, or with a broken piece of wood. If you find a saw that needs a part replaced, ask the pupil who owns the saw to replace the broken string or piece of wood before using the saw again. Remind the pupils that if they do not do this, their blade will soon become broken and it is expensive to replace a blade.