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).
Instructions discussing component tolerances, brush dust, and the effects of backward running tests.
| Identifier | ExFiles\Box 62\3\ scan0181 | |
| Date | 8th December 1924 | |
| RR 238 (150 BKS.) (OB 461-8-12-24) MP 306975 ROLLS-ROYCE LTD. INSTRUCTIONS. __________________19__ To__________________ Order No.____________ Customer's No. ? [Text in left margin, written vertically] Backward running [Main handwritten text] direction of increasing the maximum. If more tolerance is desired we think we could safely increase the lower limit to -.020". The holders being sheet pressings, do not so easily hold accumulations of brush dust as do the thick-walled cast holders. As regards the effect of backward running, we have never come across any instance of output being affected by this, nor do we know of any reason why it should, beyond the possibility of chipping of one edge of a brush or brushes as a result of it. We have made a brief test on the bench of this taking note of the peak output of a machine under fixed conditions. We then ran it backward for a few moments at a few hundred r.p.m. and then again forward, when the machine (cont'd) Signed________________ This Sheet must be filed on completion of the work. | ||