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).
Tests and observations on wheel wobble.
| Identifier | WestWitteringFiles\N\July1925-September1925\ Scan282 | |
| Date | 12th June 1925 | |
| R.R. 493A (50 H) (D.D. 31, 12-6-25) J.H.L. EXPERIMENTAL REPORT. -2- Expl. No. REF: Hs{Lord Ernest Hives - Chair}/Em2/L/G.S. 9.25. (4) Out of balance in the proportions likely to be met with in practice is quite incapable of promoting or sustaining a wobble without the reaction of the ground. (a) We added two pounds out of balance to one wheel and endeavoured to produce wobbles on wet drums - we could get no result. We dried the drums and obtained violent wobbles which vanished as soon as more water was applied. (5) Each wheel when wobbling is turned inwards when it meets the ground. Upon making contact with the ground it swings outwards. When it leaves the ground it points outwards. (a) By means of the oscilloscope we observed a slow motion high speed wobble. We could clearly see the wheel performing the motion described above. (b) By observing the marks left on the road after a high speed wobbles (see previous report) we could clearly see that each wheel in turn was performing the above evolution. (6) The majority of the turning movement of the wheel taken place as each comes in contact with the ground. (a) The oscilloscope demonstrated this - with a moderate wobble in which neither wheel left the ground the effect was somewhat masked - with a more violent wobble it could be clearly seen. (b) By means of a pencil inserted in the hub, the path described by this portion of the wheel was reproduced on a metal plate. This confirmed test (a). (c) The marks on the road shewed that in the most violent wobble experienced, practically all the angular movement took place in a one foot tyre contact on the road, 9 ft. intervening before the next contact. contd :- | ||