On Friday 16 December 2016 11:22:04 andy pugh wrote: > On 16 December 2016 at 13:29, Gene Heskett <[email protected]> wrote: > > The nut that draws the bearing > > inners together is quite tight. So I am assuming I'll have to take > > a few thou off the faces of the inner races. > > No, just space-out the outer races (by 1mm or so) then use the nut to > adjust the preload. > Some way to keep the nut from loosening will be needed. > It has a set screw, tightening against a pad that sinks into the threads, replaced by a cap screw to get additional torque. BTDT :)
> For the not lash, it probably isn't worth worrying about over-much for > a lathe. The typical lathe tool only cuts in one direction, the > backlash will end up subsumed into the tool offset. True, but TLM's backlash was at one time only about a thou. With the tapered gibs, and a solid toolpost replacing that twig from a willow tree they called a compound, its cutting better than ever now. And this Sheldon's much larger Phase-II qctp now sitting on several lbs of cast iron where the trashed & broken compound was, it should do well also. I changed the design of the armstrong bolts access to the nuts, and can now loosen then with a socket and turn the complete post (its top is off-centered) in 2% of the time it took to do that with the factory compound. In both cases, I also machined about a 1 thou hollow to both top and bottom specifically to make the contact pressure points be on the outer edges. When I get the other 2 bolts made on TLM, that bit of cast will have 4 armstrong bolts holding it down. On TLM, I now have several more times the torque resistance to the toolpost turning under load than if I had made them flatfaced. The TLMs toolpost is a single 10mm bolt mount and was pulling the compounds upper face upward in the center, so much so that with that bolt about 5 degrees from stripping the threaded hole in the compound, (I did that once, had to buy a new upper) I could still turn the post with a quite low cutting pressure. Less than satisfactory when the turn actually turns the tool tip into the workpiece. Like when turning a cylinder to a shoulder, and the tip hits the shoulder at the turnaround point just enough to turn the post CW about a thou per pass down the cylinder. Needless to say, I had to make another piece, measureing after each pass, to get it to fit. So that is another PITA removed. THanks Jon . 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
