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).
Ascertaining the period of high-speed steering wobbles using a Chronograph.
| Identifier | WestWitteringFiles\N\July1925-September1925\ Scan89 | |
| Date | 12th June 1925 | |
| R.R. 493A (50 H) (D.D. 31, 12-6-25) J.H.D. ORIGINAL. EXPERIMENTAL REPORT. Expl. No. REF: Hs{Lord Ernest Hives - Chair}/Bml/LGls. 8.25. c To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to C.J. EJ. c. to RG.{Mr Rowledge} E.{Mr Elliott - Chief Engineer} c. to DA.{Bernard Day - Chassis Design} EY. c. to Wor.{Arthur Wormald - General Works Manager} HIGH SPEED STEERING WOBBLES. 4457/44630 We have carried out a preliminary experiment to ascertain the period of the high speed wobble by means of the Chronograph. We attach to R's copy of this memo. a record we have obtained of a wobble at 60 m.p.h. The top line 'A' was obtained from two contact strips on the wheel, therefore any two marks on this indicate the time taken for one complete revolution of the wheel. The centre line 'B' was obtained from a contact which was made when the wheel on one side of the car turned outwards through 4°, therefore the distance between two consecutive marks on this line represents the periodic time for one complete wobble. The intervals between two marks on the bottom line 'C' represent time intervals of 1/10th. of a second. It will be observed that the number of complete wobbles per minute is exactly the same as the number of complete wheel revolutions per minute; this is exactly what we should expect if the wobble is set up by out of balance force on the wheel. When we have perfected our apparatus we hope to be able to give some indication of the amplitude of the wobble as well as its frequency. At the moment we are measuring wheel wobbles which cannot be felt on the steering wheel, i.e., our wobble contd:- | ||