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).
Letter addressing an issue with the doming on tungsten points and suggesting a modification.
| Identifier | ExFiles\Box 35\6\ scan 245 | |
| Date | 7th February 1927 | |
| X2894 EFC6/T7:2.27. 7th February, 1927. Mr. G.R.N.Minchin, C/o Messrs. Peto & Radford, 50, Grosvenor Gardens, LONDON, S.W.1. Dear Mr. Minchin, In further answer to your letter of the 1st inst. and in respect to tungsten points, we think it may be that the tungsten points we sent you had too much doming; in fact we think the lever point had some doming whereas it should be flat. We have now standardised the amount of doming which is sphericity only on the contact points to the extent of rising .002" in the middle, but the lever point should be absolutely flat. If your contacts are only bedding on a small circle we suggest that you could give them a clean start by having the lever point ground flat, and the other one just cleaned without removing the doming, if this is possible. Then try them again and we think the result will be better. This is only a suggestion because we do not know for certain what the original or present condition of the points is. Yours sincerely, | ||