Experiments on the effects of out-of-balance propeller shafts on the Spectre model.
| Identifier | ExFiles\Box 94\4\ scan0108 | |
| Date | 17th September 1935 | |
| To E. {Mr Elliott - Chief Engineer} c. to Nor. c. to Da. {Bernard Day - Chassis Design} c. to Hy. {Tom Haldenby - Plant Engineer} c. to RMy. c. to HX. X337 Hs {Lord Ernest Hives - Chair} /Gry. {Shadwell Grylls} 3/KM.17.9.35. Propellor Shaft - Spectre(Codename for Phantom III). We have experimented on 1-S-1 car to find the effect of out of balance of the front end of Spectre(Codename for Phantom III) propellor shafts. Out of balance was caused by adding weights used by the Works for balancing 20/25 shafts. Tests were done both on the road and with the car stationary with the back wheels jacked up. In this latter condition before any weights had been added vibrations due to the propellor shaft were noticeable at 51 m.p.h. and above 70 m.p.h. This was corrected by adding a 16 gms. weight at the usual place. We also tried 40 gms. out of balance. This greatly increased the 51 m.p.h. period and at high speeds caused various parts of the chassis to rattle, such as the gear lever. On the road the vibrations are far less noticeable. At 16 gms. out of balance the periods are only just detectable when one has a knowledge of their speeds. With 40 gms. the vibrations are unpleasant. We can say that provided the shafts are balanced to 16 gms. no trouble will be experienced. Hs {Lord Ernest Hives - Chair} /Gry. {Shadwell Grylls} | ||
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).