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).
The process for undercutting commutator bars on the 20HP chassis dynamo to clear mica.
| Identifier | ExFiles\Box 50\5\ Scan217 | |
| Date | 18th September 1923 | |
| X. 4333 EFC. BY9-P18.9.23. 20HP CHASSIS. DYNAMO. UNDERCUTTING COMMUTATOR BARS TO CLEAR MICA. In discussing this matter with Mr Davis I found that we had carried out tests as to how it could be done, proved that it could be satisfactorily put into practice and had definitely instructed the Works to cleanly undercut each Commutator bar in such a manner as to remove all the mica and also some of the copper for a depth of .025" from the top of the bar. Mr Brock has confirmed to you I understand that it is a Works fault, purely and simply. To prevent any slip of this nature recurring Mr Davis is sticking to the job until we see Commutators coming through regularly treated in the manner specified. BY.{R.W. Bailey - Chief Engineer} | ||