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).
Issues with sticking Girling expander units on experimental cars and potential solutions involving chromium plating.
| Identifier | ExFiles\Box 121\3\ scan0154 | |
| Date | 25th September 1941 | |
| 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} 1029 Rm{William Robotham - Chief Engineer}/MHR.{M. H. Rigby}2/ET.25.9.41. STICKING OF GIRLING EXPANDER UNITS ON EXPERIMENTAL CARS ------------------------- This is a trouble that has been experienced on B.V cars ever since the writer has been on the job. In the anti-corrosion drive of 1939-1940, clearances were increased and pins plated throughout the braking system on most of the cars. We failed to get New Hudsons interested in chromium plating their wedges and cones on the expander units, so we decided to treat two cars for ourselves. Rather than grind 0.002 on diameter off the wedges and cones to make room for 0.001 thickness of chromium, we increased the size of the holes in the housings by this amount. The housings are of aluminium and this job was by no means perfectly done. 9.B.V has run 25,250 miles in 18 months, and 10.B.V has run 11,000 miles in 17 months with chromium plated wedges and cones. The only trouble has been the escape of some of the grease from the off side front expander on 9.B.V. The grease got on the linings, but the blame here lies with the boring of the housing. We have since had trouble with the rears on 12.B.V, 3.B.50, 1.R.1, and we think one other car, all fitted with standard parts. Now that we have proved the benefit of chromium plating, we think we should again try to get New Hudsons interested. There are 46 front and 56 rear units in stock at Slack Lane, so our immediate interest is to have them modified. However, we are afraid that we shall meet some opposition, as their mass production methods will not allow for changes of this kind unless we can persuade them that it is to their own advantage to do all their units in this way. We then came up against their lack of chromium plating tackle. We await Rm.{William Robotham - Chief Engineer}'s opinion before getting into touch with New Hudsons. Rm{William Robotham - Chief Engineer}/MHR.{M. H. Rigby} | ||