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).
Test report on an experimental starter motor fitted with C+M.3 brushes and extra strong springs.
| Identifier | ExFiles\Box 35\1\ scan 034 | |
| Date | 30th October 1919 | |
| 30.10.19. Mr. Clark. --------- TEST OF EXPERIMENTAL STARTER MOTOR FITTED WITH C+M.3 BRUSHES AND EXTRA STRONG SPRINGS. The motor was run on load for 20 mins at the end of which time the following readings were taken. Amps 111. volts 9.7 speed 175. Spring balance 11.0 Load + scale pan 39 lbs. Torque 326 lb/ins. After this the motor was run at an excessive load for 15 minutes the amps. being about 140. It seemed impossible to break the motor down with these springs and brushes. The motor certainly did not heat up so rapidly under these conditions as with the F.7180 springs and C.M. brushes, as it ran for 30 mins under very stringent test conditions. (Sgd) L.F. | ||