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).
Outlining proposed tests for the 3.B.50 chassis, focusing on judder, brake lining wear, and brake drum cooling.
| Identifier | ExFiles\Box 111\3\ scan0152 | |
| Date | 24th December 1940 | |
| To Rm{William Robotham - Chief Engineer}, from Rm{William Robotham - Chief Engineer}/MHR.{M. H. Rigby} Copy to Rm{William Robotham - Chief Engineer}/Wym.{G. Harold Whyman - Experimental Manager} 880 Rm{William Robotham - Chief Engineer}/MHR.{M. H. Rigby}1/ET.24.12.40. 3.B.50 CHASSIS. ---------------- I should like to suggest that, when 3.B.50 returns from Hs.{Lord Ernest Hives - Chair} to the Garage, I should be allowed to take the car over for a variety of tests for which it is well suited. It is not at present required for any other use, as far as I know. These tests include the following:- 1. JUDDER EXPERIMENTS. a) Try out the servo driving plate that Vandervells have already fitted with their sintered bronze. A figure for μ can be obtained on the car by measuring wedge loads. b) Try some friction in the rear cross-shaft. This can easily be done experimentally by means of a slightly large distance piece to remove the end-float. c) A rubber washer in the position, on the servo, previously occupied by the star-springs. Up to date the judder has been removed by means of sponge in the rod from the pedal to the servo, this being a simple and adjustable method. Correctly designed, star springs on the servo would, however, be just as good, and these can be used if the above mentioned experiments are fruitless. 2. UNEQUAL BRAKE LINING WEAR EXPERIMENTS. Suitable pressure gauges have been obtained and fitted to the Pressometers for measuring wedge loads at low pedal pressures up to 20 lbs., above which it is known that the distribution front and rear is satisfactory. The effect of the increased rear cross-shaft friction can have been noted, as it should give less rear braking at low pedal pressures. 3. BRAKE DRUM COOLING. a) Obtain cooling curves for 2 rib drums of which there are two available, and also for scrap drums with all fins removed. Due to the bad scoring of the latter drums, which came off 30.G.VII, the linings would have to be bedded in. | ||