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 comparing the performance of standard brushes on a modified machine.
| Identifier | ExFiles\Box 60\1\ Scan026 | |
| Date | 13th July 1927 | |
| RR 23S (100 BKS.) (SH57.29-6-20.) MP 224358 ROLLS-ROYCE LTD. INSTRUCTIONS. To EFC Order No. PC 143 Customer's No. X8673 July 13th 1927 Test of Standard Brushes on Modified Std Machine WD.{Mr Wood/Mr Whitehead}75 For the purpose of comparing the commutation brush wear etc., of the modified machine with that of the NB machine, a test was made, using a set of standard grade brushes in the above machine. Slight brush shrieking occurred at times throughout the test. Sparking was visible at the positive and negative brushes at low and intermediate speeds, and very slightly at the negatives only at high speeds. The amount of brush dust deposited was small The commutator was blackened; much more so than that of the NB machine. The positive brushes were badly blackened over the greater part of their surfaces, while the negative and control brushes were dull over the trailing half. Cont'd.{John DeLooze - Company Secretary} Signed This Sheet must be filed on completion of the work. | ||