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).
Wiring, starter motor, and brush issues on chassis 6 EX.
| Identifier | WestWitteringFiles\E\August1920\ Scan44 | |
| Date | 28th August 1920 | |
| To EFC. from R.{Sir Henry Royce} Copy to CJ. " " HS.{Lord Ernest Hives - Chair} " " DA.{Bernard Day - Chassis Design} " " BY.{R.W. Bailey - Chief Engineer} " " EP.{G. Eric Platford - Chief Quality Engineer} " " R.R. of America Inc. (For the attention of OY.) [STAMP] ORIGINAL [Handwritten crossed out] X.3923 [Handwritten crossed out] X.3659 [Red text] RE CHASSIS 6 EX. [Handwritten crossed out] X.3082 [Handwritten crossed out] X.3034 [STAMP] RECEIVED I find the wiring of this, as pointed out previously, to be far from what I intended. You will remember that the only earthed (frame) connection that I intended to be used was through a fuse on the negative. Also, I noticed that on examination of the starter motor the brushes and field winding, and armature winding of this were all on the positive side, and therefore alive when the main switch was out. It is quite easy to arrange the main switch connected on the positive side, so that the motor and its brushes, when the main switch was off, would be at the same potential as the negative pole, which is the same potential of the frame. [Handwritten crossed out] X.3348 [Handwritten crossed out] X.2686 The motor was in an extremely clean and new looking condition and our brush holders ought to give better results than the type used on Smith and Lucas dynamo because of the flexible finger springs pressing on the carbon brush. The spring pressure seems, however, rather lighter than I consider wise, and the brushes on this motor seem to be more nearly all copper than I recommended. Bentley reports that the "LeCarbone" brushes made in France are better than "Morganite". [Handwritten] -X.3440- I shall be glad if you will send a driver to fetch 6 EX. bringing me 1 EX. or 49GB, so that it can be corrected in the wiring and in the scuttle. At present it is impossible | ||