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 Ferodo Ltd. discussing the results of tests conducted on Bonded Asbestos servo linings RAD.13 and VDM/20.
| Identifier | ExFiles\Box 141\3\ scan0110 | |
| Date | 17th October 1932 | |
| X719. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}2/MA. October 17th, 1932. Messrs. Ferodo Ltd., Chapel-En-Le-Frith. For the attention of Mr. Field. Dear Sirs, Referring to the suggestions made in your letter of the 13th, Sept., we have now conducted a series of tests on the servo linings you supplied which were Bonded Asbestos RAD.13 and the other VDM/20. We are inclined to agree with your opinion that the RAD.13 is a better all round material, and we are proposing to standardise it, the higher coefficient of friction being a definite advantage. We have not been able to notice any material alteration in the coefficient of friction over the temperatures at which our servo operates, although it would seem that μ rises slightly below 100°F.{Mr Friese} One point which we have noticed is that when we grind the faces of the linings before fitting we appear to reduce the coefficient of friction, which does not return until the linings have been running for some time. We should like to know if you consider this to be a rational result. Can you tel us at what temperature you consider RAD.13 lining is likely to deteriorate as we find that we can run it in more rapidly if we get it warm. | ||