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).
Scheme detailing the balance weight setup for a 25 HP shaft.
| Identifier | ExFiles\Box 103\3\ scan0051 | |
| Date | 4th May 1931 | |
| Y 50101 8 Balance Weight Scheme for 25 HP Shaft. E.55619 (Big Pin) All balance weights set at 180° to position of crankpin. Nos. 1, 6, 7, 12, of 1 unit each to balance 1/2 of the out of balance per crank of crankshaft only. Nos. 3, 4, 9, 10, opposite cranks, 2 and 5 to be 1/2 unit or balance 1/4 the out of balance per crank. Diagram text: 1 UNIT 1/2 UNIT 1/2 UNIT 1 & 6 2 UNITS 3 & 4 2 UNITS 2 & 5 2 UNITS Nº1 TO BALANCE SHADED AREA Handwritten text: attached to memo HS{Lord Ernest Hives - Chair}/RM{William Robotham - Chief Engineer}1/AO.4.5.31. | ||