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 Goshawk Z brushes with increased spring pressure on dynamo 288.
| Identifier | ExFiles\Box 50\5\ Scan271 | |
| Date | 20th November 1923 | |
| EFC. AB.93. 20th Nov. 1923. X.4383 - GOSHAWK Z BRUSHES WITH INCREASED SPRING PRESSURE. A set of Z brushes on dynamo 288 have been given the usual test of continuous running for the equivalent of 2500 miles and intermittent running of about 40 hours. In this test, the spring pressures were more than the standard, the positive being 1.75 lbs. the negative 1.5 lbs. and the control 1.0 lb. The brushes ran well, though sparking was about normal. The commutator was left a very good uniform light brown and the brushes themselves were slightly smoother than occurs with the lighter springs. The brush wear however is slightly more than with the normal spring pressures, being:- Positive .022", Negative .030" Control .0305". the figures for wear in the previous case, with the normal pressures being:- Positive .0075" Negative .0215" Control .0235". F.J. Allen. | ||