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).
The development and faults of a sequence starter motor and its switches.
| Identifier | WestWitteringFiles\T\2January1929-June1929\ Scan161 | |
| Date | 6th March 1929 | |
| To R.{Sir Henry Royce} From EPC. c. to Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} c. to BY.{R.W. Bailey - Chief Engineer} E.{Mr Elliott - Chief Engineer} ORIGINAL EPC4/LG6.3.29. SEQUENCE STARTER MOTOR AND SWITCHES. Y7625/3v Further to our EPC1/LG2.3.29. The taper armature (the 3.100 parallel armature ground down to 3.100/3.000), with suitable taper pole pieces has shewn itself to give a much better relation between teazer armature torque and longitudinal pull. The proportion appears to be about right, but there seems to be rather too much vigour now (apparent in increased noise of engagement) with the 17 S.W.G. sub-winding and improved operation results (at ordinary temperatures at any rate) from the introduction of some resistance in the teazer circuit. This, since we have the same number of teazer turns, is about equivalent to a return to 18 S.W.G. winding, which appears to have still a good margin of vigour for cold conditions. In regard to the damper, this too, as regards the longitudinal end thumps is effective so that we now have an arrangement which is very nearly right. We had to increase the force of the damper piston springs and now have these as well as the main armature spring apparently quite suitable. The faults of the system as now arrived at are as follows :- (1) Corner jamming occurs occasionally on first push contact but has been only very contd :- | ||