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 and weight of the Marles Steering gear for the Spectre model.
| Identifier | ExFiles\Box 28\3\ Scan145 | |
| Date | 3rd April 1935 | |
| To Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson} +4094 Hs{Lord Ernest Hives - Chair}/FJH.{Fred J. Hardy - Chief Dev. Engineer}14/KW.3.4.35. R.R. Marles Steering for SpectreCodename for Phantom III. The attached curve, Hs.{Lord Ernest Hives - Chair}1873, shows the mechanical efficiency of the above gear both before, and after, "running in". The gear was definitely tighter after "running in" and this may be the reason for the general drop in efficiency. During the "running in" one of the bolts which hold the two halves of the box together was found to be loose. This was tightened to prevent oil leaks. It is possible that this bolt had never been tight previously and that the tightening put a set up load on the cam bearings and so causing the tightness of the gear. The position of the bolt is such as to make the above possible. In view of the possibility of the above explanation, we suggest that the efficiency figures obtained after "running in" should be disregarded. The weight of the gear is as below. Weight of Gear, including steering wheel and nut, drop arm and nut, all parts for attaching to chassis, and control tubes ... ... ... 48 lbs. 10 1/2 ozs. The corresponding weight for the Marles steering on 21-G-IV is ... 51 lbs. Hs{Lord Ernest Hives - Chair}/F.J.Hardy. | ||