Letter to Morgan Crucible Co. Ltd. regarding testing and ordering of various grades of brushes for car dynamos.
| Identifier | ExFiles\Box 166\1\ img114 | |
| Date | 29th November 1938 | |
| 6142- EXPERIMENTAL DEPARTMENT. Rm {William Robotham - Chief Engineer} /RC. {R. Childs} 15/JH. 29th. November, 1938. The Morgan Crucible Co.Ltd., Battersea Works, LONDON.S.W.11. For the attention of Mr. Sparkes. Dear Sirs, As you know, we have from time to time, tried various grades of your brushes on our car dynamos, all with a view to reducing the sparking at the brushes, which occurs under extreme conditions of high speed, and maximum load. Up to now, our experience has been, that the grade of brush which is best from a commutating point of view, was unfortunately too noisy. Our present grade E.G.0, was found to be the best compromise. We have now, however reached a point where we might with advantage, try another grade of brush, having recently redesigned our machine. Our impression is, that your E.G.3. grade is the best for coping with sparking conditions, but is inclined to be noisy, while your E.G.12 grade, we believe was recommended as being quieter, but perhaps not quite so good under conditions of sparking. If we are correct in this, we would be glad if you would supply to our order, as soon as possible, four sets (eight brushes) to our drawing D.75474, but in your grade E.G.3. Yours faithfully, FOR ROLLS-ROYCE LTD. | ||
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).