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).
Technical memo about a friction device for the Spectre Servo's balance arm.
| Identifier | ExFiles\Box 95\4\ scan0112 | |
| Date | 2nd April 1938 | |
| +41 Ram Hardy SECRET Is this OK? Rm{William Robotham - Chief Engineer} HDY.{William Hardy}3/HP.2.4.38 Rm{William Robotham - Chief Engineer} To BY.{R.W. Bailey - Chief Engineer} from HDY.{William Hardy} c.Hor.P.Hs.{Lord Ernest Hives - Chair}Da.{Bernard Day - Chassis Design}RMD. SpectreCodename for Phantom III Servo - Friction for Balance Arm. N. Sch.4428 herewith shows a friction device of the flat plate type with oiled cotton duck fabric similar to the scheme recently instructed for the Bentley. The space saved by the removal of the fabric from the balance arm allows the bridge to be shortened as we show. The horizontal arm of the balance lever should be shortened by the same amount, which reduces the servo leverage by 4½%. The balance lever arm is of duralumin to reduce weight. It is important that the friction device should not limit the travel of the balance arm and for this reason care should be taken in the initial setting of the arm fore and aft. We have provided for 1" of movement each side of normal at the lever fulcrum, but it is possible for this to be taken up if the initial setting is .250" incorrect and the front and rear brakes are at their opposite extremes of adjustment. HDY.{William Hardy} N.Sch.4428 herewith. | ||