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).
Instructions for manufacturing and testing three types of front aluminium brake drums with different liners and interference fits.
| Identifier | ExFiles\Box 85\1\ scan0094 | |
| Date | 28th May 1936 | |
| To RHC.{R. H. Coverley - Production Engineer} c. to Da.{Bernard Day - Chassis Design} X206 Hs{Lord Ernest Hives - Chair}/AFM.{Anthony F. Martindale}26/KW.28.5.36. Aluminium Brake Drums. To see what reserve of strength we have in front aluminium drums, will you please make the following :- (1) One Rm.{William Robotham - Chief Engineer}55 with millenite liner shrunk in with .040" interference. The liner is to be slotted before insertion to receive fixing tabs (as these slots cannot be cut afterwards), but the 4 holes are not to be drilled and no fixing devices are required. (2) One N.Sch.4798 Drum with millenite liner shrunk in with .040" interference. No fixing devices are required, and neither liner nor drum to be slotted. (3) One N.Sch.4798 Drum with Brimol liner made to N.Sch. dimensions (i.e. .030" interference) but without fixing devices (as in (2) ). Before final turning all aluminium castings to be soaked for 24 hours at 200°C. We think heating to 240°C. should enable liners (1) & (2) to be inserted, and heating to 200°C. should enable liner (3) to be inserted. When liners are being inserted, no undue surplus of metal must be left on the inside of the liner. Hs{Lord Ernest Hives - Chair}/A.F.Martindale. | ||