Series of dated reports detailing the ongoing failure and troubleshooting of a starter motor fitted to 22 Ex.
| Identifier | ExFiles\Box 11\2\ 02-page237 | |
| Date | 5th May 1929 | |
| To Hs {Lord Ernest Hives - Chair} and Rm. {William Robotham - Chief Engineer} From G.W.H. x7941 Hotel de France Châteauroux Indre 5/5/29 Herewith the reports on the starter motor fitted to 22 Ex. 31/3/29 "We have dismantled the starter motor and found that the large diametre bearing, pinion end, had become slightly scored. It does not appear to be the right combination of metals, the shaft is soft and the gun metal tears up the ebonite moulding, for the contact had warped, altering the setting." 1/4/29 "The starter motor failure appears to be due to the large bearing having torn up and is now too large in diametre, allowing the pinion to cross bind and jam. Also an electrical fault is apparent as the main switch vibrates when the button is pressed instead of remaining closed." 3/4/29 "The spare starter motor failed after three or four attempts at starting. It was again found that the large diametre bearing(pinion end) had roughed up and worn. We came to the conclusion that one cause apart from the unsuitability of the metals was the pinion being far too deep in mesh, causing too heavy a load on the bearing. This is verified by the pinion not fully engaging when the starter button is pressed." 4/4/29 "The spare starter motor is now almost OK, the trouble is definitly firstly the starter button is too stiff in operation, contacts not reliable, secondly alteration must be made to the steel of the motor shaft and the bearing material, thirdly more clearance must be allowed in the pinion and the flywheel teeth. Too tight a mesh is fatal to the working of a starter motor." 17/4/29 "Re the starter motor, the push switch is definitly at fault. It requires a navies strengh to get the contacts made with the result that the teased winding is not conected up as it should be." 19/4/29 "The starter motor is still useless. It will not engage when the button is pressed there is a crashing of the pinion teeth on the flywheel teeth. We have done all we know to get it right, it is perfectly free whilst on the bench for movement and as far as we can see it is mechanically OK. The one thing we do not belive is working as it should do is the contact arm at the commutator end. It's movement is very limited, not at all to the same extent as on the first starter motors." 23/4/29 "We are sorry to say that the starter motor is now hopelessly ruined. We reported that it would not engage and since then although it has been on the car we have not attemted to use it. The report of the morning drivers is" whilst travelling at high speed the starter pinion suddenly engaged with a terrific noise. They immediately stopped the engine, but the starter motor kept on revolving." | ||
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).