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).
Secret internal memo discussing unexpected multiplication results in a servo system.
| Identifier | WestWitteringFiles\K\December1923\ Scan20 | |
| Date | 13th December 1923 | |
| R.R. 235A (100 T) (S.H. 159 (1-8-20) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 2800 ORIGINAL. TO HS.{Lord Ernest Hives - Chair} FROM DA.{Bernard Day - Chassis Design} SECRET. DAL/M13.12.23. E.{Mr Elliott - Chief Engineer} A.{Mr Adams} C.111. X9940 X3409 SERVO. Referring to your HS{Lord Ernest Hives - Chair}/AJLL/1G101223., we are surprised at the multiplication you obtain which is about 2½ times as great as we expected. We should be very interested if you could obtain some explanation of this if possible - for instance, we are not sure what the co-efficient of friction is. We have reckoned on .25 but we know that it is often greater than this, though sometimes it may be less. We suggest that if you left only about 2" of ferodo in the centre of the drum, and did not apply excessive pressure, that the resulting multiplication would fairly accurately represent the co-efficient of friction. As it is it seems certain that you have a fair amount of wrapping going on. Another thing we should like to know is whether this multiplication is maintained over a long period and in spite of variations of temperature. We expect that you are testing this in any case. We shall like to know because it will be necessary for us to decide how much we can depend on the multiplication you are shewing at present. DA.{Bernard Day - Chassis Design} | ||