Construction 3

Barrels mocked up in their rotors, held together with... rubber bands!

You can see one of the powerplants of the weapon: a £4.50 3.6v 250rpm cordless screwdriver from Woolworths. A similar model (in grey) is available from Wilkinson. Each one has enough torque to turn each rotor, which is surprisingly impressive for such a cheap screwdriver.

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