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).
Required clearances and tolerances for driving pins and servo discs following experimental testing.
| Identifier | ExFiles\Box 2\7\ B002_X 140 to 143-page09 | |
| Date | 26th January 1933 | |
| BY/TWD{T. W. D???Aeith} c. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. Mx{John H Maddocks - Chief Proving Officer} c. Mr. Gallimore. Y/41 BY.4/G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 26.1.33. DRIVING PINS AND SERVO DISCS. ------------------------- Will you kindly note that Experimental Department have informed us that as a result of the 10,000/miles run on the Peregrine it has been definitely demonstrated that we require a diametral clearance of .010, that is .005 per side between the pin or dowel and its bearing surface. A space of this amount, however, is apt to create the impression that the spacing of the pins or holes is not important. Our limits on the spacing must be such as to demand very accurate location of both holes and dowels, and further the limit on the diameter of the holes and/or the pins must not be of a greater order than a total of .001 as it is of the utmost importance that the drive should be taken up equally by each of the pins. BY.{R.W. Bailey - Chief Engineer} BY | ||