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).
Extract comparing the test results of different Goshawk dynamo brush materials.
| Identifier | ExFiles\Box 172\2\ img022 | |
| Date | 1st December 1923 | |
| Extract from EFC3/T10.12.23. RE. GOSHAWK DYNAMO BRUSH TESTS. "We have now made tests of Morganite brush materials EGO and EG2 (the two which did the best on previous tests), with the bu brushes and commutator in the new standard condition, and copy of my assistant's report on the results of these tests is attached. The programme of running for each brush material is precisely as previously described in our EFC6/T22.10.23. For comparative purposes we here give the wear of the EGO and EG2 brushes, together with that of the Z brushes, run under the same condition - EGO. EG2. Z. Positive .023" .018" .0075" Negative .017" .016" .0215" Control .021" .0135" .0235" It will be seen from the results that the EGO and EG2 brushes may be considered to be very nearly equally as good as the present standard Z brushes, and that either of these grades, perhaps preferably the EG2, judging from the present test, would be suitable as a second source of supply, should the supply of Z brushes fail at any time. EFC. AB.96 attached. | ||