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).
Use of cast iron versus wrought steel for dynamo magnets and the relative cost of laminations.
| Identifier | WestWitteringFiles\K\November1923\ Scan135 | |
| Date | 30th November 1923 | |
| SECRET ORIGINAL TO EFC. FROM R.{Sir Henry Royce} R3/M30.11.23. C.C. TO DY.{F R Danby} E.{Mr Elliott - Chief Engineer} A.{Mr Adams} C. DYNAMO. X 9660 Personally I was very surprised to hear that you had arranged to have this fitted with cast iron field magnet and pole pieces. I should not have supposed for one minute that the machine would have given the required flux at the slow speed. The only possible modification from the usual mild steel pole piece and magnet core is to use some of the high permeability semi-steel castings, but this can be looked into when there is more spare time. In the meantime let us push on with the more usual wrought steel. I have never been able to understand how it is that the Works concluded that magnet cores made of thick laminations were dearer than wrought ones from the solid. Very many cheap productions are designed especially to use laminations in this way. R.{Sir Henry Royce} | ||