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 moment of inertia for a lightened B.T.H. aero magneto rotor.
| Identifier | ExFiles\Box 43\4\ Scan117 | |
| Date | 17th April 1928 | |
| To R.{Sir Henry Royce} from EFC. c. BJ. E.{Mr Elliott - Chief Engineer} c. EX. RG.{Mr Rowledge} X4021 EFC2/T17.4.28. X3832/ MOMENT OF INERTIA OF LIGHTENED B.T.H. AERO MAGNETO. A lightened B.T.H. rotor similar to those provided in the two lightened B.T.H. type SC12-7 aero magnetos which we reported upon in EFC6/T4.4.28 was loaned to us by the B.T.H. Co. for the purpose of taking its moment of inertia. This we have done and the result, inclusive as before, of half the moment of inertia of the spring drive, is 1.37 lb-inches2. This is to be compared with the previous results given in our EFC2/T10.12.27, viz :- Watford rotor 1.01 lb-inches2 B.T.H. " (unlightened) 1.48 lb-inches2. EFC. | ||