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).
Article from 'The Autocar' magazine discussing the maintenance, troubleshooting, and testing of a magneto.
| Identifier | ExFiles\Box 4\5\ 05-page045 | |
| Date | 9th November 1912 | |
| 930 THE AUTOCAR, November 9th, 1912. How the Magneto Works. slightly in the direction opposite to that of the arrow." "You have told me a lot about the magneto, but what I am not clear about is what attention my magneto requires, and how am I to ascertain whether it is the magnets which is at fault in the case of trouble with my engine?" "From time to time, i.e., about once a month, the contact breaker requires examination and the platinum points need cleaning. At the same time see that the central screw is tight and the rocker is free on its pivot. Expose the distributer and see that its carbon brush and the one on the slip ring are clean. Sometimes the distributer plate takes up some of the carbon from the carbon brush which causes mis-firing. A little brass polishing compound rubbed on the plate and then polished off will remove it. This is all the attention your magneto will require, and if it be done now and again in the garage you will find you will have no trouble on the road, provided you keep your wire attachments and terminals tight, and prevent water from splashing on to the magneto." "That does not tell me whether, in the event of the engine failing, my magneto has broken down altogether." "If you have any serious reason for inspecting that the magneto has failed altogether take it off the car and remove the high tension conductor and the safety spark gap. Next attach a piece of copper wire to the terminal of the carbon brush-holder of the slip ring. Bring this piece of copper wire to within 1/8in. of the magnets, as shown in fig. 27. Move the adjustable ring of the contact breaker into the full advance position, i.e., its extreme position in the direction opposite to that indicated by the arrow. Next grip the armature spindle where it projects and rotate it sharply in the direction of the arrow. You should find that it is not very easy to rotate. Twice every revolution there should be a slight resistance owing to the strength of the magnets. If there be no resistance of this kind, in all probability the magnets have become demagnetised. At the same time, if turned sharply a spark should jump across the gap between the copper wire and the magnets twice every revolution. The quicker you turn the magneto-shaft the more powerful should be the spark. But in any case it is essential to see that the contact breaker is fully advanced. If after you have examined the contact breaker and distributer and the carbon brushes you find by this test that no spark jumps from the copper wire to the magnets, in all probability there is some defect in the magneto, and you should send it to the makers for examination. This defect is extremely rare, as the magneto has become one of the most reliable parts of the modern motor car. The Duval Spring Plates. Direct Shock Absorption Secured by Separate Belleville or Saucer-like Washers. (The rest of the text is illegible) | ||