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).
Extract discussing failures and troubleshooting of dynamos on 20 HP vehicles.
| Identifier | ExFiles\Box 51\1\ Scan189 | |
| Date | 19th July 1923 | |
| T4383 Extract from EP {G. Eric Platford - Chief Quality Engineer} 7/H19.7.23. Re 20 )HP ELECTRICAL TROUBLES X.4338. 4. DYNAMOS. X.4333. X.4383. We have had four or five of these actually fail in service. The dynamos showed distinct signs of overheating, the solder having been thrown out from the conductor connections to the commutator. On these dynamos the condition of the commutator appears to be very badly blackened and burnt, also the brushes seem to be in very poor condition, the bedding having apparently changed from its original bedding as though the position of the brushes had changed. A dynamo of this type was today brought to the attention of Mr. Brock and EFC. {E. Fowler Clarke - Electrical Engineer} , and we have sent to EFC. {E. Fowler Clarke - Electrical Engineer} a dynamo which although has not actually failed due to overheating has increased its output from its original setting, although no alteration or adjustment has been made to the dynamo since it came on test, and which we feel eventually will fail due to overheating. We are anxious to draw attention to the condition of the commutator brush gear, and also note that the nuts for the fixing brush gear at present are not tight, and the tightness of these we feel may be influenced by the alteration to the insulating material due to variation in temperature. The output automatically building itself up while running at present appear to be rather a common fault, and one which I shall be glad if EFC. {E. Fowler Clarke - Electrical Engineer} can investigate, and give some specification whereby this can be improved. Personally I am of the opinion that the bedding and control of the third brush is not at present satisfactory. The output of the dynamo is [strikethrough text] considerably influenced by the load and bedding of this brush, and I feel that very definite instructions should be given that the adjustment of the output should not be finally settled until the correct load, control and bedding of this brush has been obtained and will be maintained. Further, re Dynamos - I am also alarmed at the condition the commutator and brush gear get into after the dynamo has been in service for some time, and we have today returned a dynamo off 49-G-7 which has been returned by one of our Inspectors in London who has had to deal with the customer's complaint. He, reports as follows :- "As you are aware, we have had several complaints from the owner of this car regarding the dynamo not cutting in. We fitted the new switch box sent down by you and we tested the car and found it to be perfectly | ||