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).
Investigation into various Morganite dynamo brush grades to resolve noise issues on the Phantom and 20 HP models.
| Identifier | ExFiles\Box 62\3\ scan0021 | |
| Date | 10th February 1930 | |
| X5670. COPY. PD.43 10.2.30. X.8673. DYNAMO BRUSH NOISE X.5670. As a result of complaints of brush noise on Phantom II dynamos, having occurred from time to time the possibility of obtaining an all round better brush for both the Phantom and the 20 HP. dynamos has been considered. The position at present is that Morganite grade EG2 brushes are standard on both machines and are generally satisfactory with the exception of the complaint of noise which has so far arisen in connection with the Phantom dynamo only. Some time ago, with a view to reducing the noise of brushes, samples of Morganite EGO and EG.6630 brushes were obtained for the 40/50 dynamo. Both of these grades are thought to be possibly better than the standard, particularly the latter, which was said by the makers to be a special grade containing the maximum amount of lubricant without actually being impregnated. From an examination of the Morganite Co's. list of brushes, two additional grades namely Morganite Link 5 and Hard Morganite HM.{Capt. W. Hallam - Head Repairs}5, have been chosen as being likely to assist in solving the problem of brush noise and it is suggested that we obtain two sets in each of these two grades. For purposes of comparison, particulars of all four grades, together with those of the standard EG2 grade are tabulated below :- | ||