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 improved motor unit after 30,000 starts and subsequent component examination.
| Identifier | ExFiles\Box 165\7\ img038 | |
| Date | 20th January 1950 | |
| -4- Rm{William Robotham - Chief Engineer}/RC.{R. Childs}1/PMA. 20.1.50. with relay was removed from the motor and shown to the Lucas engineers at a meeting held at Birmingham on the 26th April 1949. Mr. Robotham, Mr. Scott, Mr. Daniel and Mr. Martin were present at this meeting. As a result of the discussion, Lucas promised us an improved type of hinge for the relay to be designed on the same lines as those used for car regulators. It was also decided to strengthen the relay bracket. See fig (c) sheet (3). We received the first of the improved type units 26.5.49., and it was refitted to Motor No.62. We then marked the motor "MRI" to indicate that it had the first of the improved type relays. This motor was then fitted to engine B.40. Mk.I No.3. for starting tests. This motor completed 30,000 starts on the above engine, after which, it was stripped for examination. The following points were recorded :- Considering the number of starts the general condition of the motor was satisfactory, but two of the poles had been slightly scored by the core of the armature at the pinion end. See print. It was also recorded that towards the end of the test, the clutch slip on starting increased, and became excessive before the test was completed. Commutator. In good condition with only slight wear. Armature. Score marks round the full circumference of the core at the pinion end. Bearings. Bore size, front end bush: 0.635" dia. Armature Shaft, front end 0.624" dia. Bore size, drive end bush 0.506" dia. Armature Shaft, rear end 0.498" dia. Cont'd..... | ||