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).
Report comparing the performance and wear of various types of commutator brushes.
| Identifier | WestWitteringFiles\K\October1923\ Scan76 | |
| Date | 22th October 1923 | |
| Contd. -5- EFC6/T22.10.23. It will be seen that the best results generally were obtained with our standard Z brushes and the Morganite +++ ++ ECO and EG2, the running of which is considered to be equally good one with the other, and possibly very slightly better than that of the Z brushes. The next in order would probably be the LFC3B Le Carbone, which though the wear is a little greater have run otherwise very well. The Le Carbone CG2 come next with good running but slightly more wear, and the HM.{Capt. W. Hallam - Head Repairs}6, and in a lesser degree the EG30, are considered to be unsatisfactory. A comparison is now being made between unbevelled brushes with the old method of undercutting the commutator, and the same brushes bevelled and running on the commutator with the new method of undercutting, in order to confirm the previously observed improvement with a view to the applicability of the new type of brush gear to the E.A.C. Without being confirmed, it is considered that the bevelled brush should be made definitely slack in the holder as regards its thickness dimension. EFC. ++ EG2 material is, in specific resistance and description, the Morganite equivalent of the Le Carbone Z, and no doubt could be used as successfully as the Z brush in the event of a failure of supply of that other. +++ ECO material is of a somewhat softer material, and of only half the specific resistance of the EG2. EFC. | ||