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).
Visit to Hughes Johnson to investigate the high cost of stampings for gearbox levers.
| Identifier | ExFiles\Box 136\4\ scan0124 | |
| Date | 14th January 1937 | |
| 1153 E.. from Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls} c. to Da.{Bernard Day - Chassis Design} c. to By.{R.W. Bailey - Chief Engineer} c. to Hdy.{William Hardy} c. to Ev.{Ivan Evernden - coachwork} Rm{William Robotham - Chief Engineer}/Gry{Shadwell Grylls}6/R.14.1.37. Visit to Hughes Johnson re cost of Stampings. Rm.{William Robotham - Chief Engineer} and the writer visited Hughes Johnson to discover why the small levers in the gearbox actuating gear cost so much. We were told that the following features are conducive to a high cost. (1) Variations in cross sectional area of more than a small amount. (2) Change of plane in the length of the stamping. (3) Sloping surfaces connecting two different planes as these make it very difficult to register the halves of the die. These have to be in a different relation to each other at the commencement of stamping, and for the final trimming. (4) Projections offset from the main plane of the stamping. Considering, for instance, part G.83352 now costing 2/9d, this would become 2/3d by elimination of the guide running on the neighbouring shaft. A reduction of a further 3d would be effected by omitting the panelling. As regards G.83293, it would considerably lessen the cost if we could reduce the .800 width of the boss. We asked about the relative prices in S.Z.N.X. Ubas and S.14, costing respectively £43, £23 and £13 per ton. On a 1/6d lever the change from SZNX to S.14 would benefit us 1d. Other firms have quoted us 6d reductions but their price in cheap steel is the same as the Hughes Johnson in SZNX, and their original price, therefore, exhorbitant. Hughes Johnson says the forging costs of SZNX are no higher than the mild case hardening steel. | ||