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).
Letter to C.A. Vandervell & Co. Ltd. regarding the quality and performance of brushes for a small dynamo and motor.
| Identifier | ExFiles\Box 51\5\ Scan183 | |
| Date | 11th November 1921 | |
| T & S H. {Arthur M. Hanbury - Head Complaints} 986. 19-8-21. G. {Mr Griffiths - Chief Accountant / Mr Gnapp} 2000 X4342.V EFC {E. Fowler Clarke - Electrical Engineer} 6/T. X4342V X435V V 11th November, 1921. Messrs. C.A.Vandervell & Co.Ltd., Acton, London, W.3. Dear Sirs, Re Small Dynamo & Motor. We thank you for the packet containing two brushes for the small motor. We find these brushes to be of C.M.C. quality, whereas the brushes supplied with the motor were of C.M.3 quality. Perhaps this is of no importance and if you think it is O.K. we will fit these two brushes so that there will be two of each quality. There might be an advantage perhaps in having the positive brushes of one kind and the negative of another, or there might be some advantage in having one each of each kind on each pole. It is certainly understood that the behaviour of positive and negative brushes is not necessarily the same, and you might have some remarks to make about this point, more particularly in connection with dynamos. With regard to the dynamo, the new brushes sent to us (H.M.6) do not blacken the commutator in the same way as the original E.G.O. brushes, and they appear to be a decixed improvement, except as mentioned below. Contd. | ||