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 proposed testing of three experimental sequence starter motors.
| Identifier | ExFiles\Box 64\1\ scan0255 | |
| Date | 1st December 1926 | |
| To RHC.{R. H. Coverley - Production Engineer} from EFC. c. BY.{R.W. Bailey - Chief Engineer} EY/RD. X7620 EFC2/T1.12.26. SEQUENCE STARTER MOTORS. X7625 Of the three experimental sequence starter motors :- G2, with 22.37 reduction gear and 34° 52' spiral, and pinion operated switch, is at present fitted to 9-EX. A2, arranged for 22.37 reduction ratio and 20° spiral, with pinion operated switch, is at present with us for test previous to being put on EAC.7 chassis 14-EX. C, at present differs from the others in not having the poles with the reduced cores and also in the number of turns of the teazer winding. Further we think this motor required a new deep slotted armature, as its own has probably been used to make up A2. In the ordinary course of events we should have been constructing this C motor for 15-EX, precisely similarly to the A motor which you have just completed. In view, however, of the fact that Mr. Royce's very new scheme of the silent starter (at present with the D.O.) involves a still lower reduction ratio for which we shall have to alter the field winding of the motor, we are desirous of making a test of the present motor, but arranged for the main field windings (only) two series two parallel, and we want to have this motor on 15-EX because the reduction ratio (22.37 to 1) has already been considerably reduced from the original reduction ratio for which the motor was designed. Will you please, therefore, instruct that there will be this one difference between the motor for 15-EX and the motor for 14-EX, and the difference will also serve as a comparison o[n]f the otherwise similar arrangement on these two chassis. | ||