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).
The specifications of the 1st speed pinion for the Wraith Gearbox.
| Identifier | ExFiles\Box 8\11\ 11-page008 | |
| Date | 12th October 1934 | |
| 628 13 To Mr. From HDY.{William Hardy} HDY.{William Hardy}2/MP.12.10.34. C. for. Mr. Hs.{Lord Ernest Hives - Chair} Mr. Cft. GRY{Shadwell Grylls} Wraith Gearbox. N. Sch.4165 herewith gives particulars of the 1st speed pinion for this box. We have not stated the radius at the root of the tooth as there appears to be no possibility of increasing this beyond what is automatically generated by a sharp cornered grinding wheel. In the case of the SpectreCodename for Phantom III pinion this radius is about .030 and is inferior to the radius given by the Lees Bradner machine in our present straight tooth pinions. We are investigating the reasons for the difference as the radii obtained on our helical gears as ground by the Maag or Pratt and Whitney machines are definitely on the small side. HDY.{William Hardy} | ||