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).
Inspection report on a 20 HP Dynamo No. 917 detailing its running qualities and minor faults.
| Identifier | ExFiles\Box 51\1\ Scan373 | |
| Date | 20th May 1924 | |
| X 4383. To EY/RD. from EFC. {E. Fowler Clarke - Electrical Engineer} EFC {E. Fowler Clarke - Electrical Engineer} 1/T20.5.24. X.4383 - 20 H.P. DYNAMO No.917. EX PRODUCTION. We have now completed our inspection and investigation of the running qualities of this machine. The result is very generally satisfactory, there being no definite fault to find with the commutation after a fair amount of running, though it was considered that both main brushes might have been bedded set with a rather larger percentage of contact area than was apparent. There are one or two points which may be remarked upon :- (1) We did not find the brush springs quite up to the limits of poundage asked for, the negative brush showed only .5 lb., the limits asked for being 1 lb. ± 3 ozs; the control brush only showed .3 lb, the limits asked for being 12 ozs ± 2 ozs. (2) We found it impossible to remove the commutator end cover without first removing the spring locking a ring of the magneto drive attachment. (3) It appears that the tool with which the undercutting is done leaves slight scratches on the working surface of the commutator, and it takes some little time of running for the effect of these to disappear. Though it is not demonstrated that any harm is caused, we should feel happier if these did not exist. The machine is returned herewith in quite O.K. condition for production. EFC. {E. Fowler Clarke - Electrical Engineer} | ||