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).
Casting errors on a Main Lever Housing from Jessop's.
| Identifier | ExFiles\Box 142\4\ scan0088 | |
| Date | 23th November 1937 guessed | |
| GW.1746 MAIN LEVER HOUSING - EX JESSOP'S. Casting submitted shows the following errors :- The inclination of the arm to the main body of the casting is 23 1/2° instead of 22 1/2°, which throws all bosses on the arm considerably out of position. The 1.400 radius shown in section AA{D. Abbot-Anderson} is -.050 on the vertical centre-line, which means that locally between the two main lever bearing housings the section of material will be reduced from .150 to .100. The .750 diameter boss on the top of the casting has been made 1.150 diameter and the 1.700 height of the boss from the centre-line of the transverse bore is -.030. The two .650 square flanges are -.030 to .050 along the top edges and one flange is also .050 short of metal on the unmachined side. The shape of the .150 web joining the two 1.000 diameter bosses at the extreme end of the arm has been altered, and whilst it was agreed that some modification would be permissible in order to facilitate foundry work, the end of the arm is very badly formed. The walls of the casting generally are badly pitted and are -.025 to .030 at various points where the section should be .150. There is a .025 to .030 shortage of metal around the two uppermost stud bosses on the large facing (3.925 centres). The .300 width of the large joint facing is -.080. There is no machining allowance on the 4.750 diameter bore of the scalloped facing. The 2.000 diameter scallops are .035 to .050 too deep, thereby reducing the width of the large circular joint by a corresponding amount. The 4.350 diameter bottom facing is .050 short of metal locally on the periphery of the flange which is also -.050 to .080 on the unmachined side. The .250 radius on the 18 1/2° inclined facing is -.040. ------------------- | ||