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).
Correspondence regarding out-of-spec Dynamo Brushes for the Goshawk 11 engine.
Identifier | ExFiles\Box 50\5\ Scan138 | |
Date | 13th November 1922 | |
X. 4333 To Ws. from BY /Ds. C. EFC. {E. Fowler Clarke - Electrical Engineer} BY {R.W. Bailey - Chief Engineer} /Ds1/ML.13.11.22. X. 4333 RE GOSHAWKAero EngineCodename for 20HP Car / Aero Engine after KestrelAero Engine 11 - DYNAMO BRUSHES D.50761. D.50736. With reference to the Inspection Departments' report attached herewith, will you kindly note that any brushes which do not come within our limits are useless to use, further we do not consider the copper depositing on the upper half of the brush necessary with rivetted connections, as this makes in some instances as much as .008 difference in thickness and unless this depositing can be kept down to the maximum of .002 increase in thickness we would prefer it to be left off. We should be pleased to know if the makers can produce these brushes to within our limits, as hitherto we were under the impression that these carbon brushes can be produced to within .001 or .002 of the sizes specified. Although not mentioned on the Inspector's report, we should like to say that some of the brushes of D.50736, which we have inspected, are also undersize, but only one or two here and there. It is very essential that these brushes should be a good fit in their holders or perfect commutation cannot be obtained. Herewith, four brushes which perhaps you would like to return to Messrs. Le Carbine, as examples of what we mean. [STAMP: REC'D 14 NOV 22] BY {R.W. Bailey - Chief Engineer} /Ds. [Signature] | ||