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).
Bench test results and potential modifications for a Watford Magneto, No. 81062, focusing on noise and clearance issues.
| Identifier | ExFiles\Box 48\2\ Scan278 | |
| Date | 13th May 1925 | |
| To Wd. {Mr Wood / Mr Whitehead} from EFC. {E. Fowler Clarke - Electrical Engineer} c. By. {R.W. Bailey - Chief Engineer} c. Mx. {John H Maddocks - Chief Proving Officer} X8796 EFC {E. Fowler Clarke - Electrical Engineer} 2/T13..5.25. X.4181. RE WATFORD MAGNETO. NO. 81062 WITH IMPROVED LOCATION OF SLEEVES. Please find attached copy of my assistant's report on the bench tests of this magneto. We are now arranging for the machine to be tested on an experimental car. As you will see from the report, although the magneto is considerably better than the average machines we have had before (it is not better than the best) in respect of noise, it does not appear to us that the finally most satisfactory condition has been obtained. For one thing, there appears to be still an appreciable amount of clearance (.002" on the dia.) at the sleeve location at the pulley end, whereas we are under the impression from By's remarks that .0005" on the dia. should provide sufficient clearance mechanically, without any fear of the sleeve being gripped. We would also like to suggest that an experimental machine be submitted, in which the air gap between the pole shoes and sleeve is suitably increased - perhaps doubled - as we think we might by this means get an appreciable reduction/effect on the performance. At any rate we are desirous of trying this point and should be glad if you would, in writing to Messrs. Norths with reference to this magneto, arrange for us | ||