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 Morganite EG2 brushes for a 2C HD Dynamo as a potential second source of supply.
| Identifier | ExFiles\Box 172\2\ img024 | |
| Date | 29th October 1925 | |
| To R.{Sir Henry Royce} from EFC. " E.{Mr Elliott - Chief Engineer} " De. " CJ " BJ. " PN.{Mr Northey} " Wor.{Arthur Wormald - General Works Manager} " EP.{G. Eric Platford - Chief Quality Engineer} " BY.{R.W. Bailey - Chief Engineer} " RG.{Mr Rowledge} X.4333 - MORGANITE EG2 BRUSHES FOR 2C HD.{Mr Hayward/Mr Huddy} DYNAMO. (In case of failure of supply of present standard Z Le Carbone brushes). ----- ORIGIN. Desirability of second source of supply in case of failure. Exptl. Test Report. The EG2 material is the nearest Morganite equivalent of the Le Carbone Z material, being hard graphitic, and having a specific resistance of .0012 ohm per inch cube. We have proved by numerous tests that brushes in this material are equally satisfactory with the Z Le Carbone, which we are using as standard. Road Test Report. A dynamo fitted with brushes of this grade of material has completed 10,000 miles on an exptl. car. The main brushes are in good condition, being very little worn, and fairly well polished. They are sliding freely in the holders. The commutator is smooth and of uniform colour. Further, examination of the machine after removing from the car now shows all the brushes to be in very good condition and free in the holders. The commutator also is excellent. The insulation of the machine is O.K. on 200 volts A.C. There is a moderate amount of brush dust deposited, and the brush wear is as follows (covering over 10,000 miles running) :- Positive .0185", Negative .0085", Control .020". A standardisation sheet for this item, dated 25.3.24, has already been completely signed, but subject to the 10,000 mile test, which at that time was not completed. A 10,000 mile test is now, however, completed and it is not considered that a further standardisation sheet is necessary. Contd. | ||