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).
Small-quantity automobile body production, aircraft industry practices, sheet metal work, and material tolerances.
| Identifier | ExFiles\Box 178\2\ img073 | |
| Date | 7th March 1940 | |
| Serial No. 7 Rx. page 2 OY 7/D/Mar.7.40 "---------structural engineers maintained close contact with the loft department --------" "---------Blueprints are eliminated." page 6 "-----calls for full co-operation between the design section and shop supervisors." And page 7 on -- description of presses and die practice. 3) All this is apropos of the fact that you have asked for any help we can give you on producing automobile bodies in small quantities. We are not going to find any help at all in the automobile production coachwork, because none of it is produced in small enough quantities to interest you. (I am going to see the Fleetwood Division of Fishers, however, as soon as I have a couple of hours.) This problem is being solved in the aircraft industry, and the repercussion of the aircraft practices developed in the next few years is going to have a profound effect on body-frame construction for automobiles in all but the largest quantities. The only man I know who is keenly up to date on this in Eng- land is Newt. Hanning at Briggs, who is striving mightily with these problems and getting a high production and a high degree of inter- changeability on sheet metal work made with wood and zinc dies. Some of this practice can also be seen at Salmon's (?) at Newport Pagnell, who use hydraulic leather-presses for forming panels for low-production coachwork. However, Newt. Hanning is your best bet on this job. There is no reason why 2500 cars of a type cannot be produced on hydraulic presses and temporary dies with all the accuracy obtained on expensive die and crank press equipment. All edge trimming would be done by hand (band saws). 4) It would be highly desirable, however, to work for accurate production of deep-draw sheet in England. We made a survey of this situation at Vauxhall and found British sheet shipments even when specified by thickness (say .037) instead of by gauge number, were hopelessly haphazard. The tolerances demanded by British mills is so wide that the gauges overlap and the mill can roll any thickness and throw the resulting sheet into some one or two bins. But it was quite evident that the sheets were not even put into the right bins according to these wide standards, since on each shipment we would get one or two sheets out of a hundred which were as much as two gauge thicknesses wrong. Under such conditions, dies (particularly temporary dies) | ||