Simple ratios. Go back to torque. Relation to speed and torque. In the pivots, could either have lots of travel, or lots of force. Here can have lots of speed and lots of torque.
Where do we get gears? Need to have some with the same teeth. Cardboard gears and language. Nails stuck in pieces of cardboard. Bent, stiffened cardboard. Bent, stiffened sheet metal.
IDEA: Provide teacher with printout to use as a stencil to cut gears out of foamboard/cardboard.
Lego gears - actually brilliant if you can get em.
Also like the idea that “a gear does not necessarily have to look like a gear”. For instance, wire gears, or gears made from corks with nails stuck in. (note, test some ways to make gears…)
PINWHEELS! http://www.cabaret.co.uk/dugs-automata-tips-techniques-and-tricks-no-3/
Pinwheels might not be great for demonstrating torque, as they might not be strong enough to handle loads that are noticeable.
Pinwheels in conjunction with cogs? Cogs: only need to be crudely cut out of wood. Pinwheels (nailwheels?) can mesh with them.
Or: Gears with inset teeth: http://woodgears.ca/gear_cutting/index.html Do this “method for drawing your own gears” http://www.instructables.com/id/How-to-make-gears-easily/step4/Working-out-the-size-of-everything/ by using simplified circles?
Could pretty easily make a jig to make inset toothed gears. Picture forthcoming!
Cut out gears onto paper, onto card, make 3-D
OR do it with bicycle gears. Chain. Sneak stuff off an old bicycle. CRANK THAT. Get the relationship between speed and torque. Come up with mechanism to do this? Pull blocks up a hill?