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).
Instructions for the final bedding and testing of dynamo brushes.
| Identifier | ExFiles\Box 62\3\ scan0456 | |
| Date | 2nd October 1934 guessed | |
| -3- This should continue until the brushes are reasonably well bedded over the whole surface. Particular notice should be taken of any undue brush noise which may develop on this test. On any brush which is noisy, it should be again checked that the clearances between the brush and its holder both axially and circumferientially, and between the bottom of the holder and the commutator, do not exceed the specified amount. Also that the bedding of the spring on the bevel of the brush and of the brush on the commutator are O.K. Failing to quieten noisy brushes in this way, the armature should be removed and the commutator skimmed, before proceeding with the final running tests. (4) Final bedding of brushes. With end cover removed and field resistance short circuited, the dynamo shall now be run on load for 3½ hours at an output of 15.0 + .5 amperes at 13.0 volts. This should render the brush bedding finally satisfactory and allow time for the machine to heat up. (5) Immediately after the termination of the above run, the speed and voltage shall be carefully adjusted until the output of the machine is 15.0 + .2 amperes, at 13.0 volts, when the speed should be measured. This should not exceed 1280 R.P.M. | ||