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 from C.A. Vandervell & Co. Ltd. concerning the supply and specifications of motor brushes.
| Identifier | ExFiles\Box 51\5\ Scan186 | |
| Date | 18th November 1921 | |
| X.4342V. COPY OF LETTER RECEIVED FROM:- C.A. VANDERVELL & CO. LTD., ACTON, LONDON, W.3. ________________________________________________ WHG/AES. 18th November, 1921. Messrs. Rolls-Royce, Ltd., Nightingale Road, Derby. Dear Sirs, X.4359V YOUR LETTER OF NOV.11 REF. EFC {E. Fowler Clarke - Electrical Engineer} 6/T. X.4342V. We ask you kindly to excuse the delay in replying, which we regret very much. Our Chief Engineer has been away ill, and your letter was unfortunately held over until his return, on account of the technical points raised therein with reference to brushes. We are sorry that through an error, C.M.C. brushes were sent for the small starter, instead of C.M.3. for, on 12-volt starters we greatly prefer the latter grade. Under separate cover, we are sending you a set of C.M.3 brushes, and also a brush spring to replace the one which has broken on the dynamo. Your information about H.M.6 brushes, and about your experiment with pads of insulating tape has been noted with interest, and we thank you for it. It would appear that the brush-holders are a little large in the bore - this is possible because that set was made by hand, pending a supply of standard parts. May we please ask you to be kind enough to send us micrometer measurements, at your convenience, of the inside of the holder, and we will then send you some more brushes. There is no doubt that under certain exceptional conditions there is some advantage to be gained by using different grades of material for the positive and negative brushes - the guiding considerations are set forth in Mr. Hunter-Brown's Paper, a copy of which is in your possession. Yours faithfully, p.p. C.A. VANDERVELL [Faint mirrored stamp text at bottom right: RECEIVED AT 11.00 A.M. 19th NOV 1921 R.R. L'TD DERBY] | ||