The four movements: hoist, trolley, slew, and travel are all powered from the E20R motor. (Mine is 70 years old – a teenage purchase at 31 shillings and 7 pence! – and still going strong.) However, when following the original build, the slewing is painfully slow, and the hoist is dangerously fast. Without the weight of the load on the hook, the cables have a tendency to slip off my pulley block, and re-threading them is an absolute pain.