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).
Investigation report into an overheated dynamo from chassis 44-GO owned by Frank Heap.
| Identifier | ExFiles\Box 47\4\ Scan209 | |
| Date | 4th December 1924 | |
| To EY. from EFC. X4118 EFC4/T4.12.24. X.4383. DYNAMO No.195 EX CHASSIS 44-GO FRANK HEAP. Answering your BY5/H1.12.24 we have now investigated this dynamo. We agree that the fault is that two of the commutator segments have become disconnected by the solder having run and been thrown. The reason of the overheating is probably due to two things taken together :- (1) Partially sticking main positive and negative brushes. (2) The fact that the control brush was too far retarded by about 60, this being one of the fairly early machines before the output was somewhat reduced. There was also a corner of the carbon brush chipped off on the main negative brush and the clearance between the control brush holder and the [handwritten: commutator] [struck-through: armature] was observed to be .125", whereas now the limit is .075". We return the dynamo herewith with the armature removed so that you may, as desired, examine the [handwritten: armature] [struck-through: commutator]. EFC. MADE AT CROXLEY | ||