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).
Specifications and calculations for a sequence starter motor with a tapered armature.
| Identifier | ExFiles\Box 64\2\ scan0094 | |
| Date | 8th August 1927 | |
| X.7625A 8.8.27. X.7625A. SEQUENCE STARTER. No.2A scheme motor as modified to give tapered armature and .250" out of centre in 'in' position :- Max. armature dia. 3.098" Min. " " 3.003" Max. pole " 3.114" Min. " " 3.025" Double air gap at in end = .022 + .250 x .089/2.750 = .030" Ditto at out end = .016 + .250 x .095/2.750" = .025" EFC. | ||