On 28 Jan 2018, at 07:00, Gene Heskett wrote: > On Saturday 27 January 2018 22:03:33 Eric Keller wrote: > >> Bison maybe? Currently considered to be pretty good, and priced >> accordingly. > > So I've noted already. > > All the Bisons I see today have a brass logo button inlaid in the face. > That does not exist and no place it was exists on this one. > I have a TOS 4 jaw self-centring chuck for my mill (lives on a plate, and faces upwards, for use holding cylindrical stock facing upwards. That's Polish, but, like the Bison, has a round recessed glued-in badge. The quality is ok. Interestingly. my impression is that there arefewer Polish chucks for sale at the moment, because the centre of low cost production seems now to be India. Don't let me get started on 'quality'. I have a Burnerd Griptru chuck on my lathe. I bought it new in 1975, and I would defend the quality and accuracy against all comers. It's an adjustable device which uses 3 conical adjustment screws in the body to bear on a loose fitting backplate, and although it holds its accuracy on everyday tasks, it can be adjusted to within 0.001mm for any given diameter (let's say half a tenth, in old money). This supplier has a useful conversion kit for standard chucks up to 5 inches http://www.hemingwaykits.com/acatalog/Adjustable_Backplate.html so I suppose you could make a device like that. It's one step up from adjustment with a machinist's hammer.
Marcus > What I am fighting with has all the earmarks of its being pulled out of > shape. Bolted to the backing plate, the body is not only eccentric, but > apparently out of round. Move the dial to the face, after refacing the > plate, and the thickness, plate to face, is around 8 thou out. I can > paper shim between it and the plate and help it, but is such a wild > variation just in turning it 45 degrees, 5 thou or so just between jaw > channels, that seems to repeat, per face section with some wobble > superimposed on that. To get it centered, I am going to have to remove > the plate, taking it to the mill, and enlarge the bolt holes by 15 thou > just so I can take a deadblow and center it, sorta, on the OD. The bolts > are a very close fit. The are places for 6 in the back of the chuck, but > only holes for 3 in the backplate. > > I keep coming back to two things, 1. the scroll is very lub sensitive, > its its swimming in vactra, it takes a hand on each end of the key to > adjust it, from any pinion. 2. Even with 10 thou or more off the OD of > the register, the bolts won't let it move far enough to get the body > concentric, maybe 6 or 7 thou total until I enlarge the holes. > > When I wanted a 4 jaw indy, I went for a $89 plate, and the $114 8". > > I have it dialed in pretty good, its within .001 of round, and once the > plate was faced, within .001 axially. > > But this one is so far out of round I hardly know where to start. So I'll > start by switching stones in the grinder, and just barely kiss the > plate, maybe taking another 2 thou off, and see if I can bolt the plate > down on the mill, use my hole locator code to find the holes in the > chuck, and make all 6 holes in the plate new and 15-20 thou bigger but > based on the chuck, not the existing holes in it. If that won't let me > true it up, I guess I'll throw real money at it. >> On Sat, Jan 27, 2018 at 10:01 PM, Gene Heskett <ghesk...@shentel.net> > wrote: >>> Greetings; >>> >>> I can't quite identify it. It has a weakly acid etched label on a >>> face but its well worn, and I can only read "made in Poland" for >>> certainty. >>> >>> Its a 3 jaw, scroll, 2 piece jaws, and about 7", maybe 7.25", in >>> diameter. Looks and feels nice & snug yet, but true it isn't even >>> with a refaced backing plate. >>> >>> Someone here once named it, but I can't seem to find it in my list >>> corpus here & now. >>> >>> I am trying to make it run true, despite a slightly bent spindle, by >>> refacing the backing plate, and find I am essentially spinning my >>> wheels. >>> >>> So I am debating replaceing it as this backing plate is a bit thin >>> for my first complaint. >>> >>> But I need to know if these Polish made chucks are good to start >>> with. >>> >>> So please tell me what you know about this one from no more than >>> I've supplied above. >>> >>> Thanks everybody. >>> >>> -- >>> 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 > > > > -- > 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
