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).
Inspection report for Dynamo 470 from chassis 6GII detailing brush wear and spring pressures.
| Identifier | WestWitteringFiles\L\2Jan1924-March1924\ Scan63 | |
| Date | 21th January 1924 | |
| EPC. AB.99 21.1.24. X.4383 - DYNAMO 470 FROM 6GII WITH ECO MORGANITE BRUSHES. This machine has now been removed from the chassis and replaced by machine E (two coils per slot). On inspection the insulation of the negative brush broke down when tested with 200 volts A.C. The brushes are in fair condition though the positive has blackened as previously reported. The brush wear over the whole period of running (6644 miles) is :- Positive .076" Negative .0185" Control .034". The commutator is in exceptionally good condition being smooth and uniform. The main spring pressures are :- Positive .7 lb. Negative .75 lb. at .05 less than the start. The control spring pressure is about the same at .5 lb. EPC/RJA. | ||