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).
Dynamo modifications, including alternative brushes and commutator materials.
| Identifier | WestWitteringFiles\I\May1922\ Scan56 | |
| Date | 10th December 1920 | |
| (2) the cheaper American scheme (with either of the above suggested modifications) which is thoroughly reliable. I think if you adopt this last suggestion, and will fit the dynamo with the Le Carbon brushes originally specified, we should have no more trouble, and the dynamo should give complete satisfaction. [Handwritten Note] R.{Sir Henry Royce} Since writing the above I have seen a further sample of Cast Commutator. quite certain it is the heat which has shrunk & weakened the Bakelite, suggesting it is an unsuitable material or we are using the wrong varnish. This confirms the conclusion arrived at in the letter to go back to Micanite using a design for which we wired today. | ||