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).
Examination report on a faulty dynamo from chassis 41-G-3, detailing issues with brush dust, melted solder, and a faulty brush spring.
| Identifier | ExFiles\Box 47\4\ Scan138 | |
| Date | 2nd November 1923 | |
| X4333 To EY. from EFC. EFC1/T2.11.23. X.4333 - RE FAULTY DYNAMO EX CHASSIS 41-G-3. HARROP. Examination of this dynamo previous to our running it, showed that the brush dust had caused partial earths (i.e. observable on 200 volts A.C. test) on all the terminals. Also that the solder from the commutator connections had melted. By cleaning this away we were able to clear all the earths except the one on the negative brush, which we think remains due to the bakelite having been carbonized by flashing over on its surface. Owing to the fact, however, that the commutator connections appeared to be quite sound (not appreciably interfering with the output or running on test) we started this dynamo on a brush wear test with the brush gear, except for the removal of the brush dust, in the original condition. After a little running we found that the negative brush spring was catching on the brush holder and therefore was not exerting its full pressure on the brush, and we consider that the running out of the solder was probably due to imperfect negative brush contact with the commutator. This dynamo is one of the early machines (No.14) and would be therefore one of the first twenty machines which were tested in our Dept. Though we are thus admitting that this was a fault which passed us unnoticed, it will be agreed | ||