The entire belt may be tensioned by a single idler pulley. Direct drive eliminates the need for a pulley, belt and belt tensioner. The sheave spins on an axle or bearing inside the frame of the pulley. The harmonic damper also does not interchange; it is a unique damper/pulley assembly. Timing belts need only adequate tension to keep the belt in contact with the pulley. Certain cordwood saws are run from a belt from a farm tractor power takeoff pulley. Belt tensions should also be adjusted to belt type, size, speed, and pulley diameters. These belts have teeth that fit into a matching toothed pulley. This kept the flat belt in the centre of the pulley. It is supported regularly at structures, by a pulley, link or clamp. Isolation exercises involve machines, dumbbells, barbells (free weights), and pulley machines. A bucket attached to a pulley system was used to dredge the cenote. Ballard said Benoit was found hanging from the pulley cable. These were accompanied by the cord pulley spanning device. He calls for Aaron and Susie and finds the pulley ropes.