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).
Experimental production of aluminium hub and drum brakes for the senior range of motor cars.
| Identifier | ExFiles\Box 121\1\ scan0338 | |
| Date | 29th October 1940 | |
| Rm{William Robotham - Chief Engineer}/GB. from Rm.{William Robotham - Chief Engineer} c. Rm{William Robotham - Chief Engineer}/MGR. 1029 Brakes General Rm.{William Robotham - Chief Engineer}14/ML.29.10.40. ALUMINIUM HUB AND DRUM. Confirming our conversation on the subject, we should like you to go into the question of producing experimentally an aluminium drum and hub for the senior range of motor car. Aluminium drums have never been satisfactory so far because the liners will not stay put. They crackle every time the brakes are used hard, and eventually, if they are cane, the liner comes loose. It did this on the 15,000 mile car. You will see from our records that Hispano's cast in their liner. I believe that with Wheeler's assist-ance and the present patterns, we can make some experiments on the Hispano lines. It will be necessary to tell Wheeler at exactly what temperature the liners should be when he casts the drum on to it, in order to get the right shrink fit. I do not see that it is necessary to have aluminium right through the liner. A few depressions in the back of the centre of the liner should be sufficient to lock it in position. If you can contact Martindale he may be able to help you on the subject. I would like to know exactly what liner material is available, so that we know with what we have to experiment. I would also like to know what the estimated sav-ing per car is if we make the drums similar to those that were fitted to J.J.G.VII. and at the same time, make the hubs in aluminium. In the final scheme you will probably have to cast in the plate against which the wheel will be bolted. Our experiments on the drums will, of course, be carried out on an existing type of hub. Rm.{William Robotham - Chief Engineer} | ||