Book 3 — A Small Rotary Pump Easily Made

The Rotating Spools Press against the Water Hose and Force the Water from It at Increased Pressure

This small power pump is made from a block of wood, a piece of rubber hose, and a 5-arm rotor of brass, with small spools attached to it. The base of the casing is 6 in. square, and of ⁷⁄₈-in. wood. A ³⁄₄-in. triangular block is set at each corner, and a ¹⁄₈-in. cover of wood, fastened at the four corners with screws. A large nail is used as a shaft for the rotor, which is cut from brass, ¹⁄₃₂ to ¹⁄₁₆ in. thick. Small spools are mounted on the arms of the rotor, and the small pulley wheel is fixed on the end of the axle. The action is simple: As the rollers on the arms revolve against the hose, the force of the stream at the discharge end is increased, the device acting as a pump. Such an arrangement was used for moving targets in a rifle range, and can be built on a larger scale if desired. A small water, or electric, motor is used to drive the pump.—S. A. Hardy, St. Paul, Minn.