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).
Comparison of specifications between a Lucas Dynamo Model C5-O Type N-O and a similar-sized Rolls-Royce machine.
| Identifier | WestWitteringFiles\V\2January1931-April1931\ Scan074 | |
| Date | 30th March 1931 | |
| To R.{Sir Henry Royce} from EFC. C.c. Eg. HS.{Lord Ernest Hives - Chair} ORIGINAL EFC./AD30.3.31. RECEIVED 1 APR 1931 LUCAS DYNAMO MODEL C5-O TYPE N-O.{Mr Oldham} A machine of the above type was obtained as a result of E's note EB/M7.2.31 originally and of Eg's note Sg{Arthur F. Sidgreaves - MD}3/21.2.31. A full examination of and tests upon this machine have now been completed with the following result. The machine being of a similar size to our own 20/25 HP. size, a comparison was made more particularly with that R.R. machine. Firstly, the following are comparative data of interest :- Quantity Lucas machine. R.R. machine. Carcase diameter. 5.000 5.000 " length. 5.000 5.000 " thickness. .250 .275 Armature diameter. 3.125 3.100 Armature active length. 2.83 2.75 Weight of complete machine. 23.5 lbs. 20.8 lbs. N.B. It will be noted that the carcase thickness of the Lucas machine is .025 less than that of the R.R. and that its armature diameter is .025 greater so that the polar length is the same. It has been one of the modifications we have had in mind, slightly to increase our armature diameters at the expense of carcase thickness particularly in view of the fact that additional reluctance in the magnetic circuit appears, up to a point, not of serious consequence. We shall be returning to this when we come to report upon results observed during further development work of our own machines, now already partly complete. | ||