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).
The performance, cost, and design of an experimental dynamo, including feedback from Mr. Royce.
| Identifier | WestWitteringFiles\F\April1921\ Scan98 | |
| Date | 21th April 1921 | |
| Contd. -6- KPC4/T21.4.21. Although this particular machine has a very early cutting in point, and in this respect satisfies our specification perhaps too readily, nevertheless the output in the hot condition is considerably less than we require, but it has this advantage, that the rise of current in the early stages is more rapid, bringing us to a high peak, after which the current falls off gradually, until for very high speeds is below 5 amperes. This, as previously stated, seems a desirable form of characteristic for an inherently regulated machine for a car as it meets both town and country running conditions, and is perhaps as effective as any form of vibrator control. It is Mr. Royce's wish that this matter be taken up with the Rotax Company with a view to their producing a machine on these lines, but slightly larger to meet the requirements of our specification. In spite of the fact that the Rotax reputation for pre-war work was not good, this particular dynamo is very well made and finished and has created with us a very good impression. R.R. Dynamo made from Starter Motor Parts. An experimental dynamo made from starter motor parts has been fully instructed to the Expl. Shop, the object of this is not so much with the idea of standardising this particular machine as to enable us to gain information which will assist us in designing our own machines. The dynamo has been instructed as a third brush single field winding controlled machine according to Mr. Royce's request. The cost of manufacturing this machine on a production basis has been got out by the Estimating Dept., this coming out at £28.12.0. It was stated, however, that this cost must be regarded as provisional as Wor.{Arthur Wormald - General Works Manager}, in looking into the details of the job, particularly with regard to labour, may be able to effect certain economies. The dimensions of this machine will be similar to those of the standard starter motor. Carcase dia. and length 6.00" by 5.175" Armature dia. and active length 3.600" by 2.250" Of Brolt and Rushmore dynamos there appear to be no suitable types listed, and Peerless dynamos are not favoured by R.{Sir Henry Royce} Contd. | ||