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).
Bump rig experiments conducted on a cast dash to measure steering column deflection and movement.
| Identifier | ExFiles\Box 17\3\ Scan222 | |
| Date | 4th April 1928 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} C. to [REDACTED] C. to [REDACTED] X7430 Hs{Lord Ernest Hives - Chair}/RmL/LG16.4.28. CAST DASH. X8500 / X7570 X 8772 We have been conducting experiments on the bump rig with the cast dash with stiffener and supports which happen to correspond fairly closely with that given in R3/M7.4.28. We measured the column deflection at the thrust race relative to the centre of the chassis at the drivers seat by means of a small indicator which measured vertical and horizontal deflection separately and was accurate to about .010". The chassis had been run some 100 hrs. on the bump to reproduce the condition of flexibility on 15-EX at the end of the 10,000 miles. The engine was fitted with rubber mounting. Attached is a tabulated list of the movements measured. The conclusions we draw from these tests are that : (1) The column can be held quite reasonably rigidly vertically by the arrangement used. (2) The inertia of the steering wheel has an appreciable influence on the vertical movement. (3) That the vertical movement is worse with the radiator connected to the dash i.e., the radiator pulls the column about. (4) That the horizontal movement is of quite a different nature to the vertical movement, and arm B. of the triangulated column support is worse than nothing. The horizontal movement is apparently due to the dash going with the frame and so moving the column. We are repeating the tests with a solid engine mounting. Clearly, nothing we can do to the dash will cure the horizontal movement, contd :- | ||