On Saturday 07 October 2017 12:30:05 dave wrote: > Rather a cute idea. :-) > So taking it a step further ... use a double column of CMU for the > headstock and a single column to support the tailstock. > Epoxy the CMU to make a good column but don't epoxy to the floor. > Use a rod end or automotive ball and socket to relieve stress on the > tailstock.
I think if on a wooden floor, I would attempt to sit the headstock on some sort of a pivot, like a crosswise (front to back) piece of pipe so that any up/down at the tail end wouldn't put a bending or bowing force on the bed. The headstock stand on this Sheldon is for the most part built that way as the piping frame is sliced off at an angle on the left end, presumably so the motor could be removed w/o having to sling it up in the air for clearance, and the actual floor contact is a pair of heavy steel tabs right at where the angle starts upward, so even if bolted down, which mine is not, it can rock some with the tailstock moving up and down w/o putting a huge up/down bending force into the bed proper. On a wooden floor, those feet would probably sink in time. OEM weight was about 1500, now probably sub 1400. Sitting on nominally 8" of non-rebared concrete. I haven't noted any new cracks in the concrete in the last 16 months, so barring an earthquake stronger than the one that damaged the Washington Monument several years back it will still be sitting there when the rhapsody comes by. > Dave > > I have to be very careful or I learn something every day. So do I:) > > On 10/04/2017 08:28 PM, John Bald wrote: > > It does seem a lot simpler now...assuming I understand the whole > > idea. So the only difference in the stand itself is the single > > contact point on the tailstock end? There is nothing different on > > the headstock end then, correct? > > > > I like your idea about using the Chevy truck upper ball joint in my > > design Gene. Found a new on one eBay for about $10 . Do you think > > 24" depth will be stable enough or should it be deeper? Not planning > > to bolt it to the floor > > > > Sent with AquaMail for Android > > http://www.aqua-mail.com > > > > On October 4, 2017 10:37:11 AM Gene Heskett <ghesk...@shentel.net> wrote: > >> On Wednesday 04 October 2017 05:43:19 andy pugh wrote: > >>> On 4 October 2017 at 02:32, John Bald <robotwiz...@att.net> wrote: > >>> > Has anyone built or familiar with the "spanning beam" or > >>> > "torsional" beam lathe stand? > >>> > >>> It seems to be giving a fancy name to a simple idea. > >>> > >>> I would imagine that a single pin joint at the tailstock end would > >>> isolate the machine from the floor even better. > >> > >> I'll second that thought Andy. My nearly 70 yo Sheldon has a spring > >> loaded ball and socket joint the right end of the bed sits on. So > >> the right bed foot can be off several degrees from level w/o > >> effecting any twist in the bed. If thats a problem, I see zero > >> reason a chevy light truck ball joint couldn't be fitted to carry > >> the load, and isolate things from a poorly poured floor. I put 2 of > >> them out in the weather 25 years ago as the pivot points for an > >> az-el satellite dish mount I made with motors and a 2 axis > >> controller. The only mistake I made was inadequate weather > >> protection for the azimuth drive jack, which lays horizontal, its > >> filled itself with rainwater, which in turn has frozen and > >> destroyed it several times. The first k band dish we had, its still > >> a 1/4 m.o.a. rifle barrel, way better that a $180k 7 meter dish > >> from scientific-atlanta. > >> > >> Cheers, Gene Heskett > >> -- > >> "There are four boxes to be used in defense of liberty: > >> soap, ballot, jury, and ammo. Please use in that order." > >> -Ed Howdershelt (Author) > >> Genes Web page <http://geneslinuxbox.net:6309/gene> > >> > >> ------------------------------------------------------------------- > >>----------- > >> > >> Check out the vibrant tech community on one of the world's most > >> engaging tech sites, Slashdot.org! http://sdm.link/slashdot > >> _______________________________________________ > >> Emc-users mailing list > >> Emc-users@lists.sourceforge.net > >> https://lists.sourceforge.net/lists/listinfo/emc-users > > > > -------------------------------------------------------------------- > >---------- > > > > Check out the vibrant tech community on one of the world's most > > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > > _______________________________________________ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > ---------------------------------------------------------------------- >-------- Check out the vibrant tech community on one of the world's > most engaging tech sites, Slashdot.org! http://sdm.link/slashdot > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
