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 The Morgan Crucible Co. Ltd. discussing comparative testing of dynamo brushes and requesting product recommendations.
| Identifier | ExFiles\Box 60\4\ Scan240 | |
| Date | 1st December 1934 | |
| 86099. Hs{Lord Ernest Hives - Chair}/Wst.1/MA. 1st December, 1934. The Morgan Crucible Co.Ltd., Battersea Works, Church Road, London, S.W.11. For the attention of Mr.Sparkes. Dear Sir, We have recently been testing a small ventilated American dynamo and we fitted for comparative tests with one of its own brushes, a brush of your CM5H grade. We were surprised to find that the American brush, sample of which I am sending to you herewith gave considerably less wear than the CM5H although they apparently appear to be of the same texture. I shall be much obliged if you will explain this for me and also whether you can recommend a brush of similar characteristics from your own range for us to try out in this connection. With regard to your list of copper morganite brushes we notice that the CM6 brush is quoted as having a lower contact drop than the CM5H whereas we should have thought the reverse to be the case. Is it possible that an error has been made in the printing of the schedule. We are doing a lot of experiments now with chassis dynamos running at higher outputs which forces us to use ultimately a copper morganite brush so that any experimental brushes in your copper morganite grade that you have to offer to us for test will be interesting. Yours faithfully, FOR ROLLS-ROYCE LIMITED. | ||