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).
Clarifying the material condition and manufacturing process for Wraith timing gears.
| Identifier | ExFiles\Box 136\1\ scan0223 | |
| Date | 29th June 1937 | |
| To HPS.{Horace Percy Smith - Experimental Factory Mgr}from Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer} Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer}8/AP.29.6.37 WRAITH TIMING GEARS. In our memo Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer}3/R.22.6.37 instructing 41° helix gears for the Wraith, we omitted to specify the material condition. Will you please leave the steel gears soft and finish by hobbing, i.e. omit the grinding operation. Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer} | ||