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 concerning the failure analysis of two faulty steering cams.
| Identifier | ExFiles\Box 153\4\ scan0096 | |
| Date | 23th May 1941 | |
| 1300 c. Rm. {William Robotham - Chief Engineer} Rm {William Robotham - Chief Engineer} /FJH. {Fred J. Hardy - Chief Dev. Engineer} 1/RH. {R. Hollingworth} 23rd May, 1941. Commdr. F.G. Matravers, Messrs. The Adamant Engineering Co., Ltd., Dallow Road, LUTON. Dear Commdr. Matravers, You may remember that some time ago, we brought to you two faulty steering cams which you kindly removed from their tubes and replaced by new cams. Our Laboratory have examined these cams and we attach a copy of their report to this letter. We are also sending to you under separate cover, the two cams in question for your examination. Cam labelled A. {Mr Adams} has run 64,254 miles on a car with 2219 lbs. front axle weight and 7½" section tyres. Cam labelled B. has run 13,026 miles on a car with 2022 lbs. front axle weight and 7" tyres. We are very anxious to establish to our own satisfaction whether there is any reason why these two cams should have less load capacity than normal, or whether we are overloading the gear. You will notice from our Laboratory report, that the depth of case is less than the low limit (0.032) on your drawings. The amount by which it is less is not, however, sufficient to make us believe that failure would not have occurred if the case had been equal to this limit. On the other hand, if the case on the worm threads of the many cams you have supplied to us in the past, has been in the neighbourhood of the high limit (0.045) then the thin case of the two cams that have failed can very well be the reason for the failures. -Over- | ||