On Monday 05 May 2014 22:13:12 Steve Blackmore did opine: > On Mon, 5 May 2014 04:48:55 -0400, you wrote: > >I suggested that a heavy steel bar, a 1x6 wide, nominally 24" long, to > >help stiffen it up, and was told its a never mind. By someone on this > >list about 2 coons ages ago. Whether I could find another at the > >scrap/recycle yard about 50 miles away, I haven't looked. As for > >added stiffness, I don't think a 1/4" plate would do anything but > >change the resonant frequency, probably down in pitch because its more > >mass than stiff at that thickness. (IMO) > > Steel plate stops the feet sinking in the wood/mdf and allows shimming > without it just sinking in. > > >But its certainly better advice now, having lived with it, sitting on > >that mdf in 2 locations now and never getting a straight turn out of > >it. > > MDF and just two bolts - no wonder it turns tapered :) Needs to be > bolted down to something rigid enough to enable you to pull the twist > out of the bed. It will have one - no doubt. The casting weren't > weathered before machining, It will have been clamped down to some > dubious surface, machined then ground, both releasing stresses and when > unclamped it twists and bends. > > My lathe came with it's own stand, it had a nice heavy cast top but it > was far too big for the available space, so I made my own. My stand is > 3" box section welded up, 10mm steel top with drip tray sandwiched > between lathe feet and top. I put a shelf in there and it has steel > panels bolted to sides and back. > > One of the best buys I made was a boxed Starrett Model 98 level, only > paid £50 for it and some other tools from a Snooker table > repairers/installers that shut down :) Multiple graduations are 5 thou > per foot and you can get damned close with a good level alone. > > My method is use the level to get it even at headstock and tailstock > ends, then use taper turning test to get it spot on. My lathe/stand > isn't level, it tilts forward and towards the tailstock, otherwise > coolant doesn't drain - but it has no twist so turns true. > > Steve Blackmore > --
I'll restart my search for a suitable piece of 1 by steel. The first place I'll look, after I get my GMC inspectable again (terminal rust of rocker panels, minor crack in windshield its had for a decade) has about 50 kilotons of magnetic scrap. They surprised me several years ago when I was lamenting that what I really needed was a solid block of alu I could saw the makings from. He went behind the scales & came out lugging one piece, about 50 lbs, roughly 6" square cross-section and around 2 feet long, obviously band sawed from a much larger 6" thick sheet. $1 a lb, I still have perhaps 10 lbs of it left. Not very hard stuff, a bit gummy to machine, but hey, it works. No level that accurate though. Set it on 3" studs, nut and washer below, nut and washer above, using them for jacking screws I could pull it whichever way reduces the error. Or bolt it down on shimstock. That would be more rigid than 1/2" studs, but that stuff is hard to come by these days, as the only old chevy's with Christian Science oil are the ones you see at antique car shows. And the last mechanic that knew how to fit chevy's rods dies in the 70's. :) Thanks Steve. Cheers, Gene -- "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> US V Castleman, SCOTUS, Mar 2014 is grounds for Impeaching SCOTUS ------------------------------------------------------------------------------ Is your legacy SCM system holding you back? Join Perforce May 7 to find out: • 3 signs your SCM is hindering your productivity • Requirements for releasing software faster • Expert tips and advice for migrating your SCM now http://p.sf.net/sfu/perforce _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
