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).
Requesting the construction of two Dynamo Armatures with specific winding and slot dimensions.
| Identifier | ExFiles\Box 61b\1\ scan0230 | |
| Date | 16th July 1931 | |
| X6126. RHC{R. H. Coverley - Production Engineer} c - Hs{Lord Ernest Hives - Chair}/Pgt. BY/RD3/W.16-7-31. RE:- DYNAMO ARMATURES. (R3/M.24-6-31) Will you please put in hand two Dynamo Armatures to the following L.O.P.S. in accordance with the request in the above memo from R.{Sir Henry Royce} One to :- D.73388 - Armature for Dynamo L.O.P. D.73388 - Armature Assembly., and one to :- D.73389 - Armature for Dynamo L.O.P. D.73389 - Armature Assembly. D.73390 - Armature Coil. D.73391 - Coil Separator. These Armature Cores are standard "N2" Series i.e. 24 slots ; therefore, the material should be available, the special feature about them being the winding and the size of the slot. D.73388/is wound with 17 gauge wire but the slot is considerably wider than is necessary and is to be filled up with leatheroid packing. D.73389 is wound with 18 gauge wire, the slots being milled to suit this smaller wire. Will Hs{Lord Ernest Hives - Chair}/Pgt. please note that the three Armatures for test will now be :- D.73388 - 17 S.W.G.winding, .085" width at bottom of tooth. D.73344 - 17 S.W.G.winding, .120" width at bottom of tooth. (Present "N2" Series standard Armature) D.73389 - 17 S.W.G.winding, .160" width at bottom of tooth. Attached herewith are Blue Prints of all the above parts, to enable this work to be put in hand. BY/RD. [Handwritten note on right]: G 16/7/31 | ||