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).
The failure of a Watford magneto H.T. collector brush due to carbonization, with a recommendation to use stabalite.
| Identifier | ExFiles\Box 48\2\ Scan326 | |
| Date | 16th November 1925 | |
| X8796 To Wd. {Mr Wood / Mr Whitehead} from EFC. {E. Fowler Clarke - Electrical Engineer} c. BY. {R.W. Bailey - Chief Engineer} EFC {E. Fowler Clarke - Electrical Engineer} 3/T16.11.25. X.8796. RE WATFORD MAGNETOS. Herewith we hand to you a H.T. collector brush which has tracked and carbonized, forming a conductor to earth for the H.T. current. This was taken off a standard magneto running on the experimental test bed, and is another example of the failure of phenol moulding after H.T. tracking. This is the fourth case we have had reported to us from the experimental test only. The following are my assistant's remarks in connection with this :- "We consider that the H.T. collector brush should be made of stabalite to prevent carbonization under tracking conditions, unless something is done to prevent the accumulation of oil and carbon dust, which one usually finds on Watford H.T. collector brushes after considerable mileage. B.T.H. apparently make their collector brushes of a stablite moulding." No doubt you will suitably take up this matter with Messrs. Norths. EFC. {E. Fowler Clarke - Electrical Engineer} | ||