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).
Test report on a P.2.KM. dynamo with a single modification, detailing necessary adjustments to the control brush angle for production.
| Identifier | ExFiles\Box 165\6\ img118 | |
| Date | 2nd February 1927 | |
| TO Mx.{John H Maddocks - Chief Proving Officer} FROM EFC. c. Mr. Brock. c. BY.{R.W. Bailey - Chief Engineer} V5660 EFC5/T2.2.27. X.5660. P.2.KM. DYNAMO WITH SINGLE MODIFICATION (POLES ONLY) This dynamo so far is the only 20 HP. machine with the single modification submitted to us by the Test Dept. to pass for production. We regret we cannot pass the output curve of this machine for production without further alteration. The output in the early stages loses a good deal on our standard curve and in the later stages is a good deal too large. Before we can pass this machine it will be necessary for the control brush to be advanced one-third of a commutator segment, i.e. 2°, so that the angle between the control brush and the main positive brush would become 123° instead of 121° as for the standard machine. We should be prepared again to test the dynamo after this change has been effected. We return this machine to the Test Dept. EFC. Since writing the above we have discovered that the control brush has already been advanced so as to make this angle 125°, in which case of course this is not a single modification machine, and the output with the single modification would be far too great. It will therefore be necessary to test the machine with an angle of about 127°, to get the 2° more than at present. | ||