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).
Calculation and explanation for conductor pitch, coils per slot, and commutator connections.
| Identifier | ExFiles\Box 68\4\ scan0239 | |
| Date | 11th April 1929 guessed | |
| -2- Contd. With an equal conductor pitch, each pitch would be 27. This will not do, however, as, owing to the use of two coils per slot, the coils would not be in the correct positions in relation to the slots. Hence pitch must be 25 on coils and 29 on the commutator connections, or, 1 + 25 -> 26 + 29 -> 55 + 25 -> 80 + 29 -> 109 the lap coil which is afterwards inserted being excluded in this numbering. EFC/CAP. | ||