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 testing of bevelled brushes and commutator undercutting methods on experimental Goshawk cars and dynamos.
| Identifier | ExFiles\Box 51\1\ Scan296 | |
| Date | 1st November 1923 | |
| Contd. -2- EFC {E. Fowler Clarke - Electrical Engineer} 1/T1.11.23. As regards the bevelling of the brushes and the new method of undercutting the commutator, we have, as reported in our EFC {E. Fowler Clarke - Electrical Engineer} 6/T22.10.23, a comparison in progress of the old brushes (unbevelled) and commutator not specially undercut, and the same brushes (bevelled) and running on the commutator with the new method of undercutting, the test being similar to the test of brushes of various materials and as described on the first page of that report. We also have brushes with bevelled tops running on the majority of the experimental GoshawkAero EngineCodename for 20HP Car / Aero Engine after KestrelAero Engine cars with or without other experiments. These with the new method of undercutting are running on 4GII and 6GII, in the one case with Z brushes (bevelled) and in the other case with EGO Morganite brushes (bevelled). The new method of undercutting and the bevelling of the brushes have been instructed on production. Further points as regards commutation not contained in our brush material report, are as follows :- We have had a machine running a short time with increased brush spring pressures, but at the moment we have appreciated no advantage or disadvantage - going by the appearance of the working brush surfaces. We have two of the dynamos on experimental chassis now running with EGO Morganite brushes. A number of tests were made some time back with EGO brushes on the Contd. | ||