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).
Unbalance issues with rationalised chassis propellor shafts and supplier coordination.
| Identifier | ExFiles\Box 148\4\ scan0123 | |
| Date | 29th June 1939 | |
| 1262. To By.{R.W. Bailey - Chief Engineer} from Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer} c. Da.{Bernard Day - Chassis Design} c. RHC.{R. H. Coverley - Production Engineer} c. By/NS.{Norman Scott} RATIONALISED CHASSIS PROPELLOR SHAFTS. We have been having some trouble recently with unbalance of the divided propellor shafts of rationalised chassis. It was eventually found that the trouble was caused by the taper at the rear end of the front shaft running eccentrically and so making the rear shaft unbalanced. The extent of the eccentricity was such that with the front shaft fitted to the car the small end of the taper on which the flange for the rear shaft fits gave a clock reading of up to 0.005". We visited Messrs. Hardy Spicer to demonstrate the incorrect alignment of the rear nose piece on the front shaft and were surprised to find that they finish machine and grind this nose piece before welding it to the tube. We asked if they could guarantee the truth of the nose piece to 0.001 clock reading, but they cannot as they have no facilities for machining this part after welding to the tube. In view of the above we consider that it will be necessary for Messrs. Hardy Spicer to send the shafts to us with machining allowance and for us to machine both the parallel and the taper portions of the nose. We have also impressed upon them the necessity of adhering to a limit of 0.25 in.oz. in the balancing of our shafts. We suggest that we should do the following as soon as possible - (1) Send Messrs. Hardy Spicer a drawing showing suitable machining allowances on the shafts. (2) Add to our drawings the limit of 0.25 in.oz. for balance. | ||