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).
Expressing disappointment with the slow progress on the Goshawk Dynamo and suggesting improvements.
| Identifier | ExFiles\Box 50\5\ Scan261 | |
| Date | 12th November 1923 | |
| To EFC. from R.{Sir Henry Royce} X4333 Rg{Mr Rowledge}/12.11.23. X.4383. RE GOSHAWK DYNAMO. X.4333. We hope that those which have been turned out can be expected to give reasonable satisfaction for a long period of use. We must aim at getting some definite progress rapidly if this is not so. When suggesting different materials for brushes I really meant you to try principally those of considerably higher resistance such as I have see-n on other machines including the Bosch. They are not electric graphites which are hard, harsh brushes, but soft, and appear like flake graphite. I don't know whether you have tested this particular type, but do not change until you find some very definite advantage. It is a very long time since I asked you to try more sections in the commutator, and also I believe I have asked several times for you to shorten the angular embrace of the pole pieces, so as to leave more time between the poles for commutation of the main brushes. The question of noise is not so urgent or important. What we want principally is long and reliable service. For some reasons it may be an advantage to have a longer air space for the sake of the difficulty with the control brush. I have thought that opposite the control brush the activity might be decreased by cutting a groove in the pole piece so as to locally increase the length of the air space. The most hopeful method should be the increased number of sections, and the higher resistance of the brush with greater space between the pole tips. I have been very disappointed with the progress we make towards definite improvements. It is too slow for a funeral. We must really buck up and see that we are getting something useful. We hear little or nothing about the E.A.C.I. dynamo. R.{Sir Henry Royce} | ||