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).
Observations on the manufacturing process of Bakelite commutators.
| Identifier | WestWitteringFiles\G\August1921\ Scan1 | |
| Date | 5th August 1921 | |
| ORIGINAL FC 4 TO BY.{R.W. Bailey - Chief Engineer} from R.{Sir Henry Royce} R7/G4/8421 Copy to G.J. HY.{Tom Haldenby - Plant Engineer} EPC. AUG 5 RECEIVED X.3573. RE BAKELITE COMMUTATORS. X.3945 X 3348 We notice that the commutator plates are made from drawn section and the drawn section is punched through a die in such a way as to produce the dove-tail shape and about three-quarters of the spoke. Probably the sections are flatted after punching, and then separated with the sheet insulation of mica or bakelite micarta. The separating mica or bakelite does not have to be trimmed to shape as it can pass right into the bakelite during the moulding processes. The insulation on the outer surface would naturally have to be shaped to permit of the pressing of the ring of plates into the steel ring which holds them firmly together while they are in the mould. It will also be noticed that the slotting of the spokes is done after the commutator is moulded into a piece. R.{Sir Henry Royce} | ||