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).
Investigating and damping low and high-speed steering wobbles, comparing performance with a Hispano car.
| Identifier | ExFiles\Box 28\4\ Scan255 | |
| Date | 7th July 1925 | |
| R.R. 493A (50 M) (O.D. 31. 12-6-25) J.M.D. EXPERIMENTAL REPORT. Expl. No. 4457 REF: HS{Lord Ernest Hives - Chair}4/LG/7.7.25. To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to CJ. BJ. c. to RG.{Mr Rowledge} E.{Mr Elliott - Chief Engineer} c. to DA.{Bernard Day - Chassis Design} BY.{R.W. Bailey - Chief Engineer} c. to Wor.{Arthur Wormald - General Works Manager} STEERING. 4214 We find we can produce low speed steering wobbles on the Hispano car which are equally as bad as anything we get on our cars. We brought up the steering wobbles by reducing the load on the balls in the side steering tube joints, i.e., we unscrewed the caps until there was hardly any set up on the springs. The amount of set up on the Hispano springs is considerable although the rating of the springs is low. We are investigating to find out whether it is the friction load on the balls which makes it impossible to produce wobbles when the car is in its standard p condition. [strikethrough]Spring control friction damper pendulum lever.[/strikethrough] Further tests with this prove conclusively that it is very effective as regards damping out low speed wobbles. Tests made under identical conditions with and without friction show that without the friction the wobbles were violent; with the friction, the wobbles could never be made to build up, there would be one or two oscillations which would immediately die out. Our tests in connection with high speed wobbles also show so far that the damped pendulum lever is a definite improvement. The characteristic of the high speed wobble is that it it starts with the front wheels leaving the ground alternately or 'tramping'. It then builds up into a wobble contd .. | ||