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).
Decision to use punched armature plates for the Phantom chassis motor, postponing the 20 HP motor update.
| Identifier | ExFiles\Box 64\1\ scan0284 | |
| Date | 24th May 1927 | |
| To EFC. X8620 BY/RDA/ML.24.5.27. PUNCHED ARMATURE PLATES. X.8620. X.5620. X.4132 X.543. X.294. Referring to EFC3/T5.5.27 and EFC2/T23.5.27. After the receipt of EFC3/T5.5.27, the starters on the 20 HP. and Phantom chassis were considered and it was decided to order the next series of material, E.2. for the Phantom chassis as punched armature plates. The Phantom motor was chosen because Sankeys already had tools to produce the internal slots to suit the shaft and it would therefore need no alteration in the design of armature shaft to use punched plates. The 20 HP. motor was left in abeyance for the time being for the following reasons :- (a) It needs an alteration in design of securing the stampings on the shaft. (b) We wish to see if Sankeys can produce the stampings satisfactorily on a production basis. Therefore, in view of your remarks that motors thus built are equally efficient and H's remarks in R1C/M30.4.27 about the stamping of plates being so much improved, it was considered worth while trying a series of motors with punched plates and no micas and benefiting by the saving in cost of mica plates. BY/RD. | ||