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 from North & Sons regarding an investigation into rotor electrode positions in relation to distributor segments for a Magneto.
| Identifier | ExFiles\Box 43\4\ Scan225 | |
| Date | 8th February 1930 | |
| X4021 SPEEDOMETERS THE BRITISH MADE Watford & MAGNETOS. NORTH & SONS, LTD. WHIPPENDALL ROAD, WATFORD. TELEPHONES: LONDON 1346 GERRARD WORKS: 592 & 623 WATFORD. TELEGRAMS: AEROMAGS WESTCENT LONDON. AEROMAGS WATFORD. CONTRACTORS TO THE ADMIRALTY, WAR OFFICE, AIR MINISTRY, CROWN AGENTS FOR THE COLONIES, INDIA OFFICE. Ref. AMA/DD Your ref. EFC2/AD. 8th February, 1930. EFC Messrs. Rolls-Royce Ltd., DERBY. Dear Sirs, We have made investigations on the subject of rotor electrode positions with relation to distributor segments. To meet the altered conditions in a Magneto with 30° range, we prepared a special diagram to set the electrode earlier at F.A. This diagram is dated 9.4.29. and all magnetos made or returned for modification to us since that date should be set to this diagram. We have prepared a sketch 857-1 enclosed, which is a copy of our diagram as regards the electrode positions. It will be noted that the sum of the angles of the segment and electrode is 15½° this gives an overlap of 5½° between the two electrodes in the extreme advance and retard points. Yours faithfully, p.p. NORTH & SONS. LIMITED. S.W. Allen | ||