A post on this page: http://yarchive.net/metal/artillery_thread.html
says: In full size practice the male and female threads are SCREWCUT (not Milled) on specially adapted, relieving lathes with an interrupted indexing motion. This usually takes the form of a special, heavy duty, "geneva" type motion. Contemporary accounts speak of "great crashings and bangings and sudden shuddering stops" accompanied by a tool point that moves in and out, under cam control, to cut the various thread diameters. On Sun, Feb 7, 2016, at 04:35 PM, John Kasunich wrote: > > > On Sun, Feb 7, 2016, at 04:18 PM, andy pugh wrote: > > Maybe I should have been more explicit about the question... > > > > How do you machine an internal part-thread that ends hard against a > > shoulder? > > > > Very carefully :-) > > This pic > http://www.eugeneleeslover.com/PAGE_56_Figure_5B10_C.JPG > shows that there was a bit of a relief groove. Cutting speeds in those > days were slower (no carbide). They may have simply run the parts > slow enough that a rapid-retract toolholder could pull clear in the time > it took to travel the width of that groove. > > > > John Kasunich > jmkasun...@fastmail.fm > > ------------------------------------------------------------------------------ > Site24x7 APM Insight: Get Deep Visibility into Application Performance > APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month > Monitor end-to-end web transactions and take corrective actions now > Troubleshoot faster and improve end-user experience. Signup Now! > http://pubads.g.doubleclick.net/gampad/clk?id=272487151&iu=/4140 > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users -- John Kasunich jmkasun...@fastmail.fm ------------------------------------------------------------------------------ Site24x7 APM Insight: Get Deep Visibility into Application Performance APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month Monitor end-to-end web transactions and take corrective actions now Troubleshoot faster and improve end-user experience. Signup Now! http://pubads.g.doubleclick.net/gampad/clk?id=272487151&iu=/4140 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
