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).
Instruction sheet detailing test results for a 20 hp Dynamo M with an annealed copper commutator.
| Identifier | ExFiles\Box 50\5\ Scan300 | |
| Date | 19th March 1924 | |
| RR 238 (150 BKS.) (BH57.29-6-20.) MP 224356 ROLLS-ROYCE LTD. INSTRUCTIONS. To: EFC {E. Fowler Clarke - Electrical Engineer} Order No.: AC.9. Customer's No.: 1 19 March 1924 20 hp Dynamo M, with Annealed Copper Commutator. This machine, set to the production test figures, has been run for the usual period on the brush testing rig. There was a small amount of sparking all round and the commutator has been left a normal brown colour, but some of the segments are burnt at the trailing edges. This however, is probably due to irregularities in the surface of the commutator itself, which in time would be levelled down. The brushes have acquired good surfaces, the positive being slightly dull across the trailing half. The wear is Positive .0075" Negative .0025" Control .0055", which is as small as any yet obtained on a standard machine. (cf A.B.92/13-XI-23.) Signed: H.J.A. This Sheet must be filed on completion of the work. | ||