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).
Approved particulars and experimental results for a sequence starter motor, including armature stroke and forces.
| Identifier | WestWitteringFiles\T\2January1929-June1929\ Scan177 | |
| Date | 20th March 1929 | |
| R.{Sir Henry Royce} from EFC. c. SG.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} c. BY.{R.W. Bailey - Chief Engineer} E.{Mr Elliott - Chief Engineer} ORIGINAL EFC1/T20.3.29. SEQUENCE STARTER MOTOR. X7621 A schedule of all latest approved particulars of sequence starter motor as fitted to chassis 21-EX and 22-EX was sent with those cars upon both of which satisfactory functioning had been experienced previous to despatch. i.e. with no longitudinal knocks. Variations of some of these items recommended for production were also indicated. (EFC1/T16.3.29) The .075 increase in the armature stroke does not reduce the initial longitudinal pull for a given current. We are just on the right side of the crest of the force distance curve so the force is actually a little more. The forces corresponding to 25 amperes on the teazer and main windings (but not in armature) as found by experiment are - Armature in full register with pole pieces 9.0 lbw. " final position of .175" short of full register. 11.0 lbw. " initial position .875 short of full register (corresponding to .700 stroke). 14.5 lbw. " new initial position .950" short of full register (corresponding to .775 stroke). 14.6 lbw. With reference to bouncing back of the armature causing jangling of the pinion teeth on wheel teeth, this only occurs slightly or occasionally when armature returns from engagement on our rig test (when releasing the push button) and has not been noticed on the cars. | ||