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 Mr Bentley discussing issues and suggestions for the manufacturing process of field coils.
| Identifier | ExFiles\Box 181\M7\ img023 | |
| Date | 28th January 1920 guessed | |
| -3- Mr Bentley (contd) justify you having a plant for these, even if you found it was not very practical for the field coils. Surely, the practica-bility could be soon tested, and I should have thought that the coils might be taped so as not give excessive draining of the bitumen, or you might arrange some centrifugal apparatus whereby a pair of coils, which would approximately balance one another, can be swung round at a high speed while hot and the extra bitu-men thrown out by centrifugal force. Some of these ideas are not very practical, but you may find something in them of use. Knowing what I do, if I were a buyer I should be afraid to buy anything from you until you had made some change in your method of dealing with these field coils. I think you are courting disaster in going on any longer with the present scheme. On reading your instructions for impregnating, one imagines that the preliminary drying time in the open stove is not fixed at any particular time, and the whole process may be gone through so quickly as to give very little chance of drying. Have you got a good dry place to store your cotton covered copper wire previous to it being used.? Do tarnished wires, which have been extra long in stock in a damp place, give extra bad results ?. Will the solid impregnating give good results if the wire is somewhat corroded under the cotton before being wound ?. I think it would be a far lesser evil to be occasionally troubled with the insulation running out of the coil than the trouble you might experience with your present system of always having coils more or less defective. With the ill effects of | ||