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).
Extract from a memo discussing the failure of back axle tubes and the implementation of an improved design.
| Identifier | ExFiles\Box 49\1\ Scan052 | |
| Date | 26th April 1917 | |
| H.H. 235a (500 T) (S.D. 408. 26-4-17.) Bm. 2/156/13. X3457 X.3457 X.1407. Extract from R4/G261118. RE 1000 - 40/50 H.P. CHASSIS (1) BACK AXLE TUBES. I am in receipt of Mr. Bailey's memo of the 22nd. inst., (BY6/P221118) and am sorry to hear we were likely to miss adopting the design shewn on LeC.566. This is so manifest an im- provement that it must be applied as soon as the tubes actually in stock are used up. It is much less treacherous, in as much as the taper bore runs straight out, and does not have to be stopped to an exact limit. You will also remember that when the earliest of these tubes were drawn, that it was the practice of cutting down to make clearance for the grinding wheels. This cutting- down was really the chief cause of the failure of these axle tubes, and it must now be realised that all these corners have a radius left in them, which can be easily obtained by having a radius on the corner of the emery wheel. The actual radius need not be to an exact dimension but we must be careful to avoid square corners, and "digging"in" of turning tools. There are other points about this tube which are manifest on reference to LeC.566, such as the extra thickness under the inner ball bearing of the road wheel. | ||