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).
Rapid wear of platinum contact breaker points in Watford E.W.6 magnetos and suggesting design improvements.
| Identifier | ExFiles\Box 65\3\ scan0373 | |
| Date | 3rd June 1929 | |
| X7791 Roy.{Sir Henry Royce} from EFC/HEW. c. Hy.{Tom Haldenby - Plant Engineer} EFC is absent EFC/HEWl/ADL 3.6.29. X.7791. WATFORD E.W.6. MAGNETOS. We hand you herewith, another contact breaker removed from an E.W.6 magneto on one of our experimental chassis 14-EX after 5,000 miles running. The points are badly worn and require replacing. This makes the 5th set we have had to replace lately on experimental chassis due to rapid wear. We consider the life of these platinum points to be very poor indeed in comparison with the battery ignition tungsten points. We would like to suggest that a slight increase in the diameter and thickness of the platinum contacts would prolong the life of these, firstly, by reducing the current density which, particularly in the latest type must be high, and secondly, by providing a greater thickness of metal to allow for more wear. We should be pleased to have Messrs. North's remarks. EFC/HEW. | ||