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).
Finishing process, grinding versus turned finish, for magnet cases on specific models.
| Identifier | ExFiles\Box 62\1\ scan0271 | |
| Date | 28th September 1934 | |
| Hs{Lord Ernest Hives - Chair}/Wst. c. Sft.{Mr Swift} c. TB. (602) BY/RD4/W.28.9.34. MAGNET CASES. With reference to your Hs{Lord Ernest Hives - Chair}/Wst6/MA.26.9.34,we wish to point out that the grinding of some types of magnet case was deleted some long time ago at the Works' request,who at that time assured us that a turned finish would be almost as good. We agree,however,that the type of finish both inside and outside on the 20/25 H.P. and Bentley starter motor is bad from appearance externally and poor for magnetic contact internally. Will Mr.Broom please reinstate the grinding operation on the inside diameter on D.72166 and DB.{Donald Bastow - Suspensions}431 Magnet Case. With regard to the outside diameter of DB.{Donald Bastow - Suspensions}431,if the Works can produce a turned surface which will look satisfactory after nickelling,then it is not necessary to grind it for any other reason,but I suggest that it is just as economical to grind it and obtain a good finish. BY/RD. | ||