cable car

Stretch fishing line across room/up stairs, wrap around shaft once. Make pulley from 2 CDs and a disk of thick card in the middle. The only adhesive that works on CDs is contact adhesive eg evostick. Or make outer discs from card as well.
Can also be used as a crane, so two will make a gantry crane.

This is one made with a hand-held battery fan

The fishing line goes once round the paperclip axle, which is attached to the fan hub with a sticky-fixer; plastic bead stops it coming off the end. Bent wire sellotaped to fan guides fishing line onto axle
another movie

Make one just with some cotton & a coke can

The bent wire and bits of straw just guide the cotton onto the right bits of the can

The cardboard round the middle gives that bit of cotton a mechanical advantage so it has to unwind when you tension the cotton, causing the other bit to wind the car uphill. The smaller the mechanical advantage the more impressive it is but it takes a bit of skill.

when you release the tension it rolls back downhill. You have to be very careful about friction of the cotton on the guides.

This is the same mechanism made from two large paperclips

The wide bit of drinking straw is held in place by wrapping tape round & round the thin bit until it's the right diameter.

brennan torpedo

This thing propels itself along a bit of fishing line stretched across a room

Because it uses an off-centre fan it turns round when it gets to the uphill bit near the end of the line. When it's going along the middle bit of the line it goes fast enough for the tail to keep it straight but when it slows down there isn't enough slipstream for the tail to work. So then the off-centredness of the fan takes charge & it pivots on its axis and goes the other way. movie
In practice I found it's quite difficult to make a fan-powered cablecar, you have to have quite a good power-to-weight ratio and as little friction as possible between the pulley wheel and the fishing line. I found it didn't work nearly as well with thicker, woven line.

movie on youtube
smuggling with a zip wire
cable logging
cable logging on youtube
good site for motors etc

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