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).
The difficulties with a large experimental worm of .900 pitch for steering systems.
| Identifier | WestWitteringFiles\R\January1928-March1928\ 24 | |
| Date | 20th January 1928 | |
| HS.{Lord Ernest Hives - Chair} BY.{R.W. Bailey - Chief Engineer} DA{Bernard Day - Chassis Design}/HDY{William Hardy} FROM R.{Sir Henry Royce} (At Le CanadelHenry Royce's French residence.) ORIGINAL. R7/M17.1.28. REC'D, & DESPATCHED FROM WW. 20.1.28. Copy to BJ. WCR. X8430 47430 DIFFICULTY WITH LARGE EXPERIMENTAL WORM OF .900 PITCH. I cannot understand why this should be so, because the angle of the worm threads is less liable to give irreversibility than the .720. The object of the .900 larger diameter was to give less end thrust for a given effort on the road wheels, and greater area of oil film to carry this reduced load. EAC.7. is now the best steering we have ever known (shorter pendulum lever) - (Dodd's report) on these most trying roads - rough surfaces, also an extraordinary number of sharp dangerous turns. R.{Sir Henry Royce} | ||