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).
Comparing different interleaving materials based on thickness, durability, friction, and cost.
| Identifier | ExFiles\Box 154a\2\ scan0261 | |
| Date | 15th March 1940 | |
| - 2 - Cont'd.{John DeLooze - Company Secretary} The life of a given material is approximately proportional to the square of the thickness, and the thickness is only limited by appearance and cost, weight being nearly negligible. From this point of view the best thickness is between .080" and .100". It will thus be seen that the Ferrodo Jackson board is definitely the material to go for since it is much tougher than the American stuff, has a low coefficient of friction and is of a reasonable thickness (.080"). The V.G.91 material was really developed to overcome the creaking trouble which we thought we had run into, but hardly it seems as if we shall need it now that we have proved that the creaks were in several cases due to metal to metal contact. However, as Ferrodo's have gone to a lot of trouble to make it we propose to try it on a car and find out it's life so that we can use it if we run into trouble with Jackson board. Ferrodo's estimated that the untipped Jackson board would cost us about 2/- per spring. We are proposing to try this on a car, and alsowith the two longest interleaves reinforced with bakelised tips, which would increase the cost to about 3/-. These costs are for 1,000 off. We think we ought to be able to make some use of the Woodhead rig to do some more tests on interleaving. They should be able to give us a pointer on the life of Jackson board and V.G.91 as compared with the American stuff and Spaulidite. We should also like to have an opportunity of looking at the rig in case we could see any reason why the results they obtained in the past did not agree with our results under road conditions. Rm{William Robotham - Chief Engineer}/Cln. | ||