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 material selection and testing for the Goshawk starter motor flywheel gear.
| Identifier | ExFiles\Box 75\5\ scan0084 | |
| Date | 21th December 1922 | |
| X4250 c. R.{Sir Henry Royce} c. CJ. c. Hs.{Lord Ernest Hives - Chair} GOSHAWK STARTER MOTOR. Referring to R4/M71222 I will arrange to have a large gear on the flywheel made up in .4 to .6 carbon steel which contains a reasonably high percentage of manganese. We will heat-treat these, so as to just allow them to be cut reasonably. I propose instructing Hs{Lord Ernest Hives - Chair}, by means of a drawing to obtain three of these gears and try them out for reliability and wear. The reason I had not suggested the steel in question was that with the percentage of carbon required to give a good brinell figure at the finish, the resistance of the material to an izod test is remarkably low. The impact effect of the pinion approximates more to the Izod test, and therefore I was rather inclined to think the material would tend to be somewhat troublesome in service conditions. Hs{Lord Ernest Hives - Chair}, test, however, will elucidate this fact quite definitely. BY.{R.W. Bailey - Chief Engineer} Hs{Lord Ernest Hives - Chair} RECEIVED DEC 21 1922 | ||