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).
Page of testing procedures for a magneto, detailing checks on the contact breaker, running speeds, and spark gap performance.
| Identifier | ExFiles\Box 57\2\ Scan154 | |
| Date | 20th December 1926 guessed | |
| -2- Contd. (3) The contact breaker lever shall be replaced, and a test shall be made of the tangential force at lever pin radius necessary to cause advance or retard. In various positions this shall everywhere lie between the limits 2 lbs. and 4 lbs. To secure this, if necessary, an adjustment of the cover springs should be effected. (4) The machine, with the control lever in the central position, shall now receive a preliminary run at 1500 r.p.m. for half a minute with the secondary winding short circuited, and following this, a second run with lever advanced for half a minute with the high tension discharge taking place on the safety spark gap. (5) The magneto shall now be run at 2000 r.p.m. with the advance lever central for a period of 10 minutes, during which time no missing shall occur on a 4.5 mm. three-point spark gap in air, and the noise of the machine shall be reasonable. Subsequently, the magneto with the lever fully advanced shall be speeded up from this speed to a speed of 3600 r.p.m. and maintained at this speed for one minute, during which time regular sparking on the 4.5 mm. gap shall be consistently maintained. (6) The slowest speeds at which regular sparking will occur on a 4.5 mm. three point spark gap in air, shall now be ascertained and shall not exceed - Contd. | ||