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).
Fault on Dynamo No.197, specifically a depression on the commutator due to improperly cleared mica.
| Identifier | ExFiles\Box 47\4\ Scan143 | |
| Date | 9th November 1923 | |
| X4383 To BY.{R.W. Bailey - Chief Engineer} from EFC. c. HY{Tom Haldenby - Plant Engineer}/Ds. EFCB/T9.11.23. X.4383 - RE DYNAMO No.197 - WILLIAMSON. This dynamo has been found to have a depression on one portion of the commutator which allows each brush to descend momentarily during rotation. We think this depression has been burnt away due to mica not having been properly cleared away from the slots in the first instance, as we have had a few cases of a similar kind on some of our driving motors on which the mica is not recessed. We are returning the dynamo for your examination of this particular point before carrying out any tests upon it, as it seems useless to run the machine in this condition, there being little doubt that the brush wear would be excessive. EFC. | ||