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).
Improvement to Phantom dynamo brushes by altering the bevel angle to reduce chattering.
| Identifier | ExFiles\Box 60\1\ Scan051 | |
| Date | 16th October 1928 | |
| X8673 To BY.{R.W. Bailey - Chief Engineer} from EFC. c. BY/RD. EFC3/T16.10.28. PHANTOM DYNAMO BRUSHES. We have reason to believe that an improvement in the minimisation of brush chattering would result in the utilisation of a brush bevel angle of 45° instead of 15°. We have tried some brushes bevelled by hand to 60° with apparently some amount of improvement, the result of which test has indicated to us that 45° is about right. We should therefore be pleased if you will arrange to have ordered from the Le Carbone Co. two sets of brushes, otherwise standard, but with the bevel altered from 15° to 45°. These special brushes should be carefully kept apart from standard supplies, and sent to the Elec. Expl. Dept. as a special delivery addressed for the attention of the undersigned. EFC. | ||