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).
Evaluation and modification of various Lucas dynamo models.
| Identifier | WestWitteringFiles\F\April1921\ Scan95 | |
| Date | 21th April 1921 | |
| Contd. -3- at low speeds would amply comply with our requirements, but it would not have the falling off of current at high speeds such as we think is right, and further, would be subject to a certain amount of trouble due to singing. In any case it was decided by Mr. Royce that this big machine would be quite unsuitable as standard. We have from time to time put up to Messrs. Lucas the kind of performance we require and suggested that a dynamo of about 33 lbs. weight, i.e. somewhere between the A.400 and the E.575, both in performance and in other respects would probably meet our requirements, but apparently Messrs. Lucas' have not seen their way to design a machine of the type we have in mind. Lucas C.575 Dynamo. They did, however, submit to us a sample four pole C.575 machine with concentric armature which did not meet our requirements either as regards performance or non-singing and was therefore reported to be unsuitable for standardisation, being no advantage, taking all things into consideration, over the E.575 machine. We understand Messrs. Lucas have made further experiments on a machine of this type, but have been unable to get the silent running we require, and they state that in view of the urgency of the matter, an E.575 machine with armature lengthened 1" axially on the armature carcase and poles, but with exactly similar end fittings, has now been put in hand. Lengthened E.575 machine. The suggestion of lengthening the present machine came from Mr. Royce about the end of 1919 and was passed on to Messrs. Lucas very soon after that. Messrs. Lucas apparently did not favour the idea at the time but seemed keen on finishing the C.575. As already stated, however, they are now showing preference on the E.575 machine with lengthened dimensions and hope to be able to give us favourable reports of this machine shortly. Such a machine would give earlier cutting in speed and very nearly the same output, and if it could be made to be a non-singer, would very nearly comply with our specification. The use of such a machine would also make the minimum change on the present standard system. The weight of this machine ought to be as suggested above - about 33 lbs. and the price should not be very materially more than the present standard. H.W. 589v (100 L) (2 H.{Arthur M. Hanbury - Head Complaints} &W' 208' 10-18-20) C. 3074 Contd. | ||