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).
Test report on the wear of different brushes and their effect on a commutator.
| Identifier | ExFiles\Box 165\6\ img068 | |
| Date | 20th June 1920 | |
| RR 238 (T50 BKS.) (SH57. 20-6-20.) MP 224358 ROLLS-ROYCE LTD. INSTRUCTIONS. To Order No. Customer's No. 19 The wear of the brushes is:- Positive .014" Negative, .013". Control .0375". The result obtained with these brushes is much superior to that obtained in October 1924 (AC 28) with LFC2, a very similar soft grade, which polished well and wore less. The wear is not as large as that obtained with EGA and EG3417 grades however. The commutator has been left clean but with slight roughness on many of the segments, by the LFCSABT brushes. Apparently they do not supply enough excess lubrication to prevent chattering of the control brush. Signed F.H.A. This Sheet must be filed on completion of the work. | ||