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).
Comparative tests of different grades of bakelite moulding material, specifically Stiff X.616B.
| Identifier | ExFiles\Box 61\1\ scan0121 | |
| Date | 29th May 1930 | |
| X6011 Ey. from EFC. c. Ey/RD. c. Sft{Mr Swift}/Mr Brock. EFC4/AD29.5.30. X.6011. X.616B MOULDING MATERIAL. X.7513. Comparative tests of the grade of X.616B bakelite material called Stiff X.616B, and the ordinary X.616B grade have now been completed, the general results of these tests are contained in my assistant's remarks which are as follows. "It is seen" (from the figures observed) "that the Stiff Bakelite compares favourably with both the ordinary bakelite and present standard Redmanol as regards leakage, and since it has the additional advantage of not contracting there appears electrically, to be no reason why it should not be used in preference to any of the others. It is understood however, that the Stiff powder is somewhat difficult to mould so that for this reason production may prefer to use both powders i.e. the ordinary bakelite X.616B. and the Stiff grade of X.616B. reserving the latter for use in moulding parts where contraction is of consequence" It will be remembered that in our EFC5/AD24.4.30 reporting on the results of comparative tests of the ordinary X.616B and the Redmanol, we stated that we had an ignition coil in a case of this material running on 10,000 mile test chassis 23-EX. This test has now been completed and it is reported that no evidence of misfiring occurred whatever. Although this is satisfactory we do not attach much importance to it as to the fact of the leakage figures taken on the bench showing the leakage to be quite reasonable and very much less than we used to obtain on coil cases of material which was known to be unsatisfactory for use on the cars. EFC. | ||