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 The Morgan Crucible Company Limited regarding the composition and supply of starter motor brushes.
| Identifier | ExFiles\Box 35\1\ scan 018 | |
| Date | 19th September 1919 | |
| S.A. 1228 CODES: A.B.C. 4TH & 5TH EDITION, A1, LIEBERS, & WESTERN UNION (UNIV. EDIT.) X. 2656 Inland Telegraphic Address. "CRUCIBLE, BATTSQUARE, LONDON." (2 words only chargeable) Cable Address. "CRUCIBLE, LONDON." Telephone No BATTERSEA 2250. (5 LINES) X. 3348 The Morgan Crucible Company Limited. Battersea Works, Church Road, London. S.W. 1/ 19th September 1919 MORGANITE TRADE MARK Za/CP IN REPLY PLEASE REFER TO Z DEPT Messrs. Rolls-Royce Ltd. Nightingale Road, Derby. Dear Sirs, X.2656 Re Brushes for R.R. Starter Motor. X.3348 We thank you for your letter of the 17th inst. Ref. EFC6/T, contents of which we have carefully noted. The trend of present practice for Starter Motors is to use a metallic brush with a rather greater graphite proportion than is contained in Link CM or Link CM1. We agree that Link CM4 is too graphitic, but exceedingly good results have been obtained on Starter Motors with brushes of our Link CM3 type, (a quality sample of which we enclose herewith). The contact resistance of this grade is, of course, higher than for Link CM, but the tendency to-day is to use it and employ a higher brush pressure, say 6 lbs. per square inch. We are, therefore, preparing sufficient Link CM3 brushes in your standard design G.3901 to enable you to make a proper test, and we will ask our Engineer Representative, Mr. H.{Arthur M. Hanbury - Head Complaints} T. Sparkes, who is expert in dealing with these Car Lighting and Starter brush problems, to take them down to you on Wednesday morning next, when he can discuss the whole question fully with you. | ||