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 to A.T. Speedometer Co. Ltd. about a faulty speedometer drive cable causing pointer oscillation.
| Identifier | ExFiles\Box 165\2\ img211 | |
| Date | 7th December 1939 | |
| 6065 Rm{William Robotham - Chief Engineer}/RC.{R. Childs}5/JH. 7th. December, 1939. A.T. Speedometer Co.Ltd., Chronos Works, North Circular Road, LONDON.N.W.2. For the attention of Mr. Arrowsmith. Dear Sirs, We have received from our road test department, a speedometer drive cable, which they complain causes the pointer of the speedometer to oscillate instead of giving a steady indication. They report that they have had several cables behave in this manner, in addition to which, some have been noisy; the one sent to us being an example of the main trouble. This cable was tried by us on the bench and by comparison with others, it was confirmed that it caused excessive oscillation of the pointer at all readings up to over 20 miles per hour. From an examination of the cable, we could only find two things which might possibly be the cause of either or both troubles. One was that the square end of the cable which fits into the instrument appeared to run eccentrically as though not quite central. The other was that the driving end of the cable was found to be just pushed into the gear-box end fitting, whereas we had the impression that it should be soldered in. In connection with this latter point, however, we should say that this particular drive cable, was one of a number of eight-feet length units obtained from you and cut down to the required length by ourselves. | ||