Worm Gear Junk Automata
To make your own worm gear you will need:
A short length of 9mm diameter dowel
1mm diameter wire
Chupa Chups Lolly
Print out the downloadable page onto normal printer paper and cut out the lined rectangle. Wrap the paper round the dowel at an angle so that the striped lines make a long spiral. This will act as a guide for your worm gear.
Wrap the 1mm wire around the dowel four times following the lines to ensure that the spiral is evenly spaced.
Slide the wire from the dowel.
Carefully bend the ends of the wire so that they run across the diameter of the circle.
Bend the ends so that they point out from the centre of the spiral.
The gear and washers are made from 3mm laser cut ply using the downloadable file as a template. Several layers of thick card would also work if you have the patience to cut it by hand. The axle is a bamboo wooden skewer.
Thread the parts onto the skewer. The stick from a Chupa Chups lolly is made from hollow plastic tube. Cut two 7mm lengths from the end of the stick to use as axle tubes. Straighten a paper clip and wrap the end around the axle tube. Bend a dog-leg into the wire as shown. Make two like this. Thread each end of the worm gear wire through the two axle tubes then press the other ends of the paperclips into the top of the cork. Make sure that the worm gear spiral runs across the centre of the cork and is level.
Make two wires with dog-legs and loops to hold the gear into place.
Trim the spiral wire and fold it into a handle.
Turn the handle and the spiral ‘worm’ moves the gear one tooth for each turn of the handle.