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).
Letter detailing design requirements, specifications, and assembly instructions for an experimental starter motor.
| Identifier | ExFiles\Box 51\5\ Scan103 | |
| Date | 1st May 1921 | |
| DA {Bernard Day - Chassis Design} /THH/CBG-5-21. contd. we desire to have a shoulder on the shaft against which our distance bush butts. This shoulder can, within reason, be made to suit yourselves, but we require shaft drawing to give the dimension X on "N" Schme 838. On receipt of this drawing with these particulars we shall be able to complete the shaft. We should like to point out also, that the outer race of the ball bearing for the driving end is clamped, and therefore any lateral movement of the shaft must be provided for on the commutator end. Also, the small numerals which appear underneath the dimensions of our drawing, are permissible limits of variation in thousandths of an inch. We assume that opening for cables is on the top vertical centreline from your preliminary outline drawing please confirm this. We thin it would be advisable to give you a few more particulars of the starter motor. The direction of rotation will be anti-clockwise looking on the commutator end. It will require to start a six-cylinder engine - cylinders 3"x4.5" on a gear ratio of 8.4 to 1. When the parts are all complete we would propose to send them on to you in order that they may be completely assembled for motor testing purposes before finally dispatching to us. We will arange for an official order for this experimental motor to be forwarded in course of a few days. Yours faithfully, FOR ROLLS-ROYCE LIMITED. | ||