Teach the Cast
Some of MachineForge’s cast are still learning. When you teach them, YOU learn it best — catch what they get wrong, then quiz them.
Teach Pry
You be the teacher — Pry is still learning. Helping Pry figure it out is the practice. (Only for you; nothing is saved.)
Teach the connections
Show how the simple machines connect
You've helped them one at a time. The real understanding is how the ideas CONNECT — teach that next.
Ramp (inclined plane — climb the long slow way for less force) × Auger (screw — a spiral inclined plane, round and round)
Why do we say a screw is 'just an inclined plane in disguise'?
Ramp then says: “A screw and a ramp are completely different machines with different rules.” — is that right?
The link: the screw is the inclined plane rolled around a post.
Coil a ramp and you've made a screw.
Pry (lever — push longer to lift heavier, around a fulcrum) × Spoke (wheel-and-axle — one turn of the hub, many turns of the rim)
How is turning a big steering wheel to move a small axle the same idea as prying with a long bar?
Pry then says: “A wheel has nothing to do with levers — it just rolls.” — is that right?
The link: a wheel-and-axle is a lever that goes all the way around.
Bend a lever into a circle — that's a wheel.
Capstone — build one lifting machine together
Three simple machines, one heavy load. Bring in the cast member for each.
Push a long bar over a pivot to lift a heavy rock. Who?
Who do you bring in?
Pull a rope down here to raise a bucket up there. Who?
Who do you bring in?
Roll a heavy barrel up a gentle slope instead of lifting it straight. Who?
Who do you bring in?
The synthesis: pry, hoist, and ramp — three ways to trade a bit of distance for a lot less force.
Lever, pulley, ramp — the load goes up easy.
Try it in the machine lab →
