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).
Technical memorandum detailing modifications to the B.50 steering and yoke piece dies for different caster angles.
| Identifier | ExFiles\Box 112\3\ scan0020 | |
| Date | 16th September 1938 | |
| 850 To Da.{Bernard Day - Chassis Design} from Da{Bernard Day - Chassis Design}/DB.{Donald Bastow - Suspensions} c. By.{R.W. Bailey - Chief Engineer} Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer} Ev.{Ivan Evernden - coachwork} Da{Bernard Day - Chassis Design}/DB.{Donald Bastow - Suspensions}3/N.16.9.38. B.50 Steering and Yoke/Piece. [Handwritten signatures: MEB, FJH{Fred J. Hardy - Chief Dev. Engineer}] [Handwritten note: M50 file] Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer}1/MH.{M. Huckerby}13.9.38, calls for 2º positive caster, and Rm{William Robotham - Chief Engineer}/IMW.{Ivan M. Waller - Head of Chateauroux}10/MH.{M. Huckerby}14.9.38 calls for 1º positive caster, on B.III, and it has been decided that B.50 shall also be brought into line with this. In order to cater for both possibilities, it is suggested that the dies for the B.50 yoke piece shall be sunk to a figure intermediate between these two, i.e. 1º caster. Whichever angly is then adopted, the king pin hole will be started centrally in the bottom face of the king pin boss, and the out-of-centre of the hole in the boss will be not more than 0.011" at the top. The diameter of the top part of the boss is then increased by 0.025" to deal with this. The dies should therefore be sunk to the following figures, modifying the particulars of PD.251 as stated: 2.572" dimension becomes 2.588" 1.831" " " 1.793" 3º14' angle becomes 3º54' 1º20' " " 0º17' in reverse direction. 1.200" boss diameter becomes 1.225" If the 2º positive caster angle is finally required the 2.588" and 1.793" dimensions will be retained, the 3º14' angle becomes 3º47' and the 1º20' angle is deleted: whereas if the 1º caster angle is required, the 2.588" and 1.793" dimensions are again retained, the 3º14' angle becomes 4º0' and the 1º20' angle becomes 0º30' in the reverse direction. The 1.225" boss diameter will be shown in either case on the detail although it will of course not represent the actual forging shape. The steering levers as instructed in Da{Bernard Day - Chassis Design}/DB{Donald Bastow - Suspensions}6/N.15.9.38 will be required for B.50 also. Da{Bernard Day - Chassis Design}/DB.{Donald Bastow - Suspensions} [Handwritten signature: DB{Donald Bastow - Suspensions}] | ||