On Sunday 16 July 2017 02:21:41 Marcus Bowman wrote: > On 16 Jul 2017, at 06:37, andy pugh wrote: > > On 16 July 2017 at 02:46, Gene Heskett <[email protected]> wrote: > >> Which will do the least damage to a pre-finished part, such as the > >> fairly high polished SS barrel? Brass or copper? > > On a three-fingered steady, a different approach is to add rotating > bearings to the ends of the fingers. I made a set which use thin ball > bearings designed for the bottom bracket on a bicycle. The fingers are > forked at the end, with the bearing running on a short hardened shaft. > The bearing turns rather than rubs. I would recommend an arrangement > which allows the bearing to turn slightly, to align itself with the > surface of the shaft. My fingers are square-section because the > original design of the steady has flat surfaces against which the > fingers slide. Circular-section fingers would be better, to allow the > fingers to turn to align the outer track of the bearings to align > against the work. > > Second thought: I may have misunderstood about fingers rubbing on > threads; but can you make a female threaded sleeve for your threads? > That would give you a circular sacrificial surface for the fingers to > rub against.
Not needed, Marcus, the P-17 threads are square, so lots of bearing surface. A bigger problem is getting them adequately centered on the bore. I have a new ball bearing center on order as this old one seems to have a considerable amount of slop. I will not attempt to do that critical work until the new center arrives. Some of this I should be doing between centers, driving the workpiece with a dog, but I don't have a 5C to MT2 adaptor. I might see if I can find one tomorrow. My bed is calling me now. Thanks Marcus. 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 [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
