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).
Experimental tests of a dynamo armature and main brush retard settings.
| Identifier | ExFiles\Box 165\6\ img104 | |
| Date | 11th July 1927 | |
| RR 250 (150 BKS.) (BH57.29-4-20.) MP 224355 ROLLS-ROYCE LTD. INSTRUCTIONS. 19 To Order No. Customer's No. 3. The main brushes being found to be at 6.5° retard. (Standard on diagram 7°.) An experimental armature giving a 4° main brush retard was fitted to dynamo 1337 and ran about 12000 miles on 10GIII in France, the output being adjusted somewhat high. The result was satisfactory as reported AC71. 11-VII-27. This machine has been used for further tests comparing the performance with main brushes at 4° retard and 10° retard respectively, the end-plate of the machine being slotted to provide the variation. The 10° position gave results much better than the 4° position in point of output for a given heating. In other respects there was little difference. Signed (Coutts) This Sheet must be filed on completion of the work. | ||