From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Mechanical efficiency test results for a Marles Weller Q Type Steering Gear.
| Identifier | ExFiles\Box 28\3\ Scan082 | |
| Date | 11th December 1934 | |
| x4094 HS{Lord Ernest Hives - Chair}/FJH.{Fred J. Hardy - Chief Dev. Engineer}12/KW.11.12.34. Mechanical Efficiency of Marles Weller Q Type Steering Gear. The Steering Gear on which the following efficiency tests were carried out is one of the two Q type Marles Weller Gears that were tried on Phantom II in 1932-33. The gear was dismantled, cleaned thoroughly and lubricated with Mobiloil 'D' before being tested. The results of the tests were as follows :- All efficiencies measured under static conditions at mid position of travel. Overall turns of steering wheel = 3.32. Overall movement of pend. lever = 73°. Overall ratio of box = 18/1. Mid. position ratio of box = 17.4/1. Pendulum lever length = 7.60". The following table shows the mechanical efficiency at various loads - | Pendulum Lever Load lbs. | Mechanical Efficiency | |---|---|---| | | Forward | Reverse | | 50 | 48.0 | 35.9 | | 100 | 53.5 | 32.3 | | 150 | 52.6 | 32.1 | | 200 | 52.2 | 33.1 | | 300 | 51.8 | 33.6 | | 400 | 52.3 | 32.8 | | ||