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 thickness and angle of the carbon arm flat spring for the S.S. Starter Main & Auxiliary Switch.
| Identifier | ExFiles\Box 64\4\ scan0256 | |
| Date | 26th April 1929 | |
| X7655 BY/RD. from EFC. R c. HHC. EFC1/T26.4.29. S.S. STARTER MAIN & AUXILIARY SWITCH. The thickness of the carbon arm flat spring which we have experimentally found most satisfactory is .020, and the angle of set 7½°. Will BY/RD. please arrange to alter the detail drawing D.71741 and production instructions in accordance with the more approved thickness. EFC. | ||