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).
Instruction sheet comparing the properties of different grades of Morganite and Le-Carbone brushes.
| Identifier | ExFiles\Box 60\1\ Scan136 | |
| Date | 17th December 1929 | |
| ROLLS-ROYCE LTD. INSTRUCTIONS. To: EFC Order No.: PD42 Customer's No.: X8673. Special Grade of Morganite Brushes; EG6630. As the result of enquiries concerning details of the above grade of brush, the following particulars were supplied by the representative of the Morganite Brush Co. who paid us a visit today. These are tabulated, for purposes of comparison, with similar details of other grades of brush which are of interest. TABLE: | | Morganite | | Le-Carbone | | | |---|---|---|---|---|---| | | EG2 | EG6630 | Z | EG3417 | LFC | | Specific resistance (ohms per inch cube) | .0010 | .0013 | .0012 | .0006 | .0010 | | Contact drop (Volts) at normal density. | .9 | 1.2 | 1.8 | 2.5 | 1.6 | | Coefficient of friction | .22 | .14 | .22 | .23 | .15 | | Approx. maximum speed. (ft. per min.) | 4,000 | 6,000 | 4,000 | 5-6,000 | 10,000 | | Normal current density. (Amps. per sq. inch) | 55 | 60 | 50 | 65 | 65 | Signed: C.A.P. This Sheet must be filed on completion of the work. RR 236 (150 BKS.) (DB{Donald Bastow - Suspensions} 431-8 12 24) MP 306975 | ||