Good description, Gene. Have you ever considered makin' one of them new-fangled u-tube videos of your adventures?
On Sun, Jan 28, 2018 at 10:49 PM, Gene Heskett <ghesk...@shentel.net> wrote: > On Sunday 28 January 2018 12:39:48 Jon Elson wrote: > > > On 01/28/2018 01:36 AM, Marcus Bowman wrote: > > > 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, > > > > Actually, TOS is Czech, but supposed to be VERY good stuff. > > Their high-end chucks go for several thousand $. > > > > Jon > > > I have come to the conclusion, after taking this chuck apart, that its > possible it is a Bison, but well aged, made before they started inlaying > a brass logo disk in the face. Its a 6.25" chuck. > > The grease in it was much like cold crayons for consistency unless there > was a big gob of it that apparently settled to the bottom over several > decades without motion. Had a heck of a time getting the scroll disk out > as it fit so tight it bound in the hole if tilted 10 thou. Had to put a > bar of poly in thru the jaw slots, and drive it out 10 thou at a time > with a small hammer. > > Turning the striped body over, I noted the serial number, 4670, was > splashed up 3 or 4 thou around the numbers, I knocked them down with a > smiths diamond plate, then cleaned the mill table and put it face down > on the mill. Lowered my CBN cup wheel down to pinch a sheet of 20 lb > under it, wrote a quick loop to drive it in a circle, dropping .0001" > for each pass around the circle. Then realized that the head likely > wasn't perfectly trammed, so I dropped a plug in the bore hole so it > could only move a quarter inch, then restarted the wheel and turned it > by hand, dropping it .0001" about every full turn. And I was right, tram > was off so it did all the kissing at about the left third of the wheel. > Kept that up for about a half hour, until the back face was clean all > the way around. Some of the bolt holes were pulled up around a thou for > a 1/4" around them. Washed it out clean with paint thinner, using a good > bit of a box of Scott towels, smeared some lithium based chassis grease > into the scroll's resting place, and had just as much fun re-seating it. > That fit could only be achieved useing chalk for the final abrasive, > I've done it on $8000 camera lenses. Cleaned up the pinions, greased the > scrolls teeth and the pinions and reinstalled those. Feels like well > greased fine machinery now. Put the scroll catcher rear center piece > back in, (I should mention I found one of those 3 bolts about a turn > loose when I took it apart), and it still turned sweet and smooth. > > Cleaned up the jaws and reinserted them. Jaws can move maybe 5 thou > before running into the scroll, so there's no drag there. Put some of > that chassis grease in the face of the scroll while I could, then ran > half a teaspoon of stp into the ball oiler. Smooth and silky. > > Looking at the backing plate, wishing I had a thicker one, I'll go see > TSC about 3 more bolts tomorrow so it will have a bolt in every hole. > They are spaced evenly, or at 60 degrees, but I'll have to use the mill > and holefinder routine to find the exact diameter of the circle, cutting > all the holes 15 thou bigger as I go. This will have to be done while > its clamped face down so I can use the holefinder.ngc to find the > x,y=0.00000 center of the bolthole circle by referencing the inside edge > of the smooth rear spindle hole. And find a flat, sacrificial to lay it > on letting the holddown clamps do the grounding. If I do the math right, > it ought to Just Work(TM). ;-) > > We'll see how my luck holds out, as it will probably be Tuesday before I > can mount and try to adjust it. At the pace I work, I'll be doing good > to get all the holes milled to the new size and the bolts test fitted > tomorrow. > > Thanks for reading this far, comment if you like. :) > -- > 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 > -- "Anyone who believes exponential growth can go on forever in a finite world is either a madman or an economist." -Kenneth Boulding, economist Corporations are NOT people and money is NOT speech! ------------------------------------------------------------------------------ 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
