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).
Dynamo failure, discussing brush wear, and outlining further testing and development for the 6-Goshawk-11 model.
| Identifier | ExFiles\Box 46\2\ Scan201 | |
| Date | 21th April 1922 guessed | |
| contd:- -2- The dynamo on this car failed entirely today - the commutator burst and this has damaged the machined beyond repair here. We will carry on for the next few days without it and at the end of 10,000 miles, Hs{Lord Ernest Hives - Chair} and I propose to bring the car back to the Works for dismantling and examination. We propose to leave Waldron, Maddocks and Appleby here to run 6-G-11 for the time being. Hs.{Lord Ernest Hives - Chair} and I are of the opinion that 6-G-11 cannot be looked upon as a final model for manufacture in all its details as such parts as brakes, shock absorbers and steering require improvement. Nevertheless, we think that the running will be useful as the car is more powerful, is faster, has better carburation and has the shock absorber joints, steering joints and spring shackles protected. If all goes well we should bring 6-Goshawk-11 across on Tuesday or Wednesday next. It is rather important that we should have details of this failure. Does Hy.{Tom Haldenby - Plant Engineer} consider that the production work on this should be stopped pending investigation. Is it not possible that the excessive wear of the brushes may have been due to the commutator plates having become loose. According to the Expl: Dept: records, the dynamo on 4-G-11 was fitted with grade "O" le carbone brushes. 5-G-11 grade C.G.3. le carbone. 6-Gell C.G.3. le carbone but E.G.3. morganite for control brush. On 6-G-11 the control brush was made narrower as per EFC. suggestion, approved by R.{Sir Henry Royce} Is the excessive wear on 6-G-11 particularly bad on the control brush and is the carbon formed due to the bad contact made to the commutator owing to the faulty brush holders as referred to? Do we take it that 5-G-11 is satisfactory as regards the brushes not wearing, this car having run about 9000 miles compared with 6-Goshawk-11 only about 2000 miles. Hy.{Tom Haldenby - Plant Engineer} since wires that the steering box has broken which may possibly delay this proposed programme. It also seems important that 6-Goshawk-11 should have some modifications made to the spring shackles so as to try and evolve some improvement to overcome the rattle which Hs.{Lord Ernest Hives - Chair} reports is one of the worst weaknesses with the car. Hy{Tom Haldenby - Plant Engineer}/Hs.{Lord Ernest Hives - Chair} | ||