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).
Letter requesting a cost comparison for crankshafts with different balance weight configurations and materials.
| Identifier | ExFiles\Box 132\1\ scan0141 | |
| Date | 3rd June 1939 | |
| 1116. Experimental Dept. Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell}2/MH.{M. Huckerby} 3rd. June, 1939. The English Steel Corporation, Vickers Works, SHEFFIELD. For the attention of Mr. Crossley. Dear Sirs, We wish to obtain a cost comparison between crank-shafts with separately bolted on balance weights against crankshafts with the balance integrally forged with the crank-shaft. This is in respect of our chassis units for which you already produce the forgings for the crankshaft (EW.1379) the arrangement drawing of which we enclose, (EW.913) showing the balance weights which are the loose bolted on type in position. Assuming we asked you to produce similar crankshafts with the similar balance weights as an integral forged job, how would the cost compare with the bare crank forgings (EW.1379) both in respect of the dies and the actual produced cranks ? Another point on the same subject is, what is the comparative cost between a crank forging in .6 carbon steel as against the VCM which we normally use ? At the present time we machine the crank webs all over, such that the forging is well over the finished size to enable this to be carried out. Assuming this machining was deleted and it became necessary to forge the cranks very close to the final size, would the cost of the forging vary to any extent from the present condition where an ample surplus amount of metal is left on the crank ? | ||