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 performance and wear characteristics of various commutator brushes.
| Identifier | ExFiles\Box 50\5\ Scan245 | |
| Date | 22th October 1923 | |
| Contd. -3- EFC6/T22.10.23. EG2 Morganite Brushes. This set ran more smoothly and the positive brush is polished over the leading three-quarters of its surface. The control brush, which sparked more than is usual is duller. The commutator was left brown with slight irregularities. The wear is:- Positive .014", Negative .017" Control .042". HM.{Capt. W. Hallam - Head Repairs}6 Morganite. Brushes. The positive brush is marked characteristically. All are rather rough and the control brush sparked badly throughout the test; although the commutator was left in very good condition, being clean and uniform. The wear is:- Positive .0435", Negative .0375", Control .0785". L.F.C.3.B. Le Carbone. This set was run with EGO control brush as no control sizes in LFC3B were available and the main brushes could not be filed down, owing to the riveted pig-tail connection. The positive is slightly duller than the negative though both ran well. The commutator was left slightly rough, but clean and uniform. The wear is:- Positive .033", Negative .040". EG.30 Le Carbone. Fair sparking occurred all round with these, and the commutator was left dark and somewhat patchy. The wear is:- Positive .055", Negative .026", Control .0515" | ||