Dynamo sparking issues, special armatures, and suitability for different driving conditions.
| Identifier | ExFiles\Box 168a\3\ img187 | |
| Date | 10th April 1935 | |
| - 2 - BY.1/G.10.4.35. our scheme to be checked up on Bn {W.O. Bentley / Mr Barrington} 's car, as we considered that he dealt with both sides of the case and if high speed was dangerous with the armature he would certainly demonstrate it. Taking the particular case cited by Hs {Lord Ernest Hives - Chair} /Wst. - Mr. H. {Arthur M. Hanbury - Head Complaints} Helder's Chassis No. B.32-AH. This car was entered for the Bournemouth Rally, and was therefore running under precisely the kind of condition that I pointed out would be unsuitable for the dynamo fitted with the early cutting in armature, and since my information was so positive on this point I am extremely interested in knowing how the decision to fit the dynamo of the city driving type to a machine driving all night all-out in a Rally arose. We were well aware of the fact when making our original recommendation that there was a tendency to increase sparking, but this matter was given intensive consideration and an improved method of flatohing the commutator was arranged for which resulted in practically eliminating any increased sparking effect on this type of machine as compared with the standard, in fact Hs {Lord Ernest Hives - Chair} /Wst. and I, with HY {Tom Haldenby - Plant Engineer} /BD {Mr Berend} , examined a machine of each type, and it was agreed that the difference in sparking was negligible. NO Only sufficient of the special armatures are being made to meet actual customers complaints. The first batch instructed was one dozen, these were used up and a further dozen was ordered. In the first dozen there were six machines which showed rather more sparking at high speed than standard, and in the last dozen there was only one. This taken in conjunction with the fact that we warned everybody that the machines were special for city conditions and were not to be recommended for drivers doing long night journeys, is in my opinion a sufficient safeguard, and I consider that the special dynamo is necessary to meet city conditions until the new machine which is being developed and contains many of the features of the special one is available. By BY. {R.W. Bailey - Chief Engineer} | ||
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).