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).
Extract from a letter concerning dynamo failures on Goshawk engines, detailing issues with brushes and commutator.
| Identifier | ExFiles\Box 50\5\ Scan040 | |
| Date | 8th May 1922 | |
| [Handwritten]: X.4333 Extract from letter from R (Le CanadelHenry Royce's French residence) 8.5.22. X.4333. RE GOSHAWKS X.4086. X.4383. X.4219. Dynamo. Kindly find out how it was that thebrushes I said were to be used on he dynamo were not used, after my sending twice or three times exact instructions that certain "Le Carbon" brushes were to be used, someone fitted Morganite, and even there the wrong type, i.e. high conducting soft copper ones instead of low conducting, hard, pure carbon ones. Those responsible should lose their position; they have cost the Company much trouble, money, and damaged my reputation, showing my confidence in them and my policy wrong. The commutator flying to pieces might be through excessive heat and sparking at the brushes, but I think we ought to make this impossible by using steel rings to reinforce the Bakelite and pass by a steel tube or equivalent, so as to keep the end rings from spreading. [Drawing of a commutator part with a handwritten note]: possibly broke through here and [Strikethrough]and-t[/Strikethrough] allow this and this to come out end-wise, rather than the end rings bursting by tension, so that like an ordinary commutator the end ring might be reinforced by a short piece of steel tube, i.e. steel ring, and the steel shaft or a tube be fitted with nuts and washers to hold the Bakelite together end-wise. You will remember that our dynamo runs at 4500 revs. when the car is going really fast, it should be tested to 5,500 at all temperatures. [Footer]: R.R. 198 (500) (SD) 29S. 15.8.17) M.P. 176549. | ||