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).
Cause and cure for 'Wraith Servo Judders'.
| Identifier | ExFiles\Box 108\1\ scan0417 | |
| Date | 24th February 1938 | |
| To Rm{William Robotham - Chief Engineer}/IMW.{Ivan M. Waller - Head of Chateauroux} from Rm{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale} File 600a Rm{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale}10/MH.{M. Huckerby}24.2.38. WRAITH SERVO JUDDERS. We find we can stop this phenomenon on 28.G.VI by fitting low /u servo linings (V.G.90, herewith) and 35° servo cams. The output is then normal. The star springs have to be retained. The judder appears to be due to the usual cause but very high frequency due to rigid brakes, and this makes it difficult to deal with. we are trying various possible cures. In the meantime we suggest you fit the V.G.90 and 35° cams, and see how you get on. We note that servo judders started when you fitted the 40° cams. Rm{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale} | ||