On Sunday 07 February 2021 15:57:46 John Dammeyer wrote: > > From: andy pugh [mailto:[email protected]] > > > > On Sun, 7 Feb 2021 at 20:10, <[email protected]> wrote: > > > Perhaps using a collet results in more variability of tool lengths > > > compared to an R8 alone. However, I doubt that either way is > > > reproducible to less than several thou. > > > > The whole class of 7/24 tapers rely on pulling back to the same > > place every time. A solid R8 should be just as good, the taper angle > > is the same to within less than half a degree. > > I still have to use the R8 for somethings like the floating tap > holder, Face mill, larger than 1/4" drill chuck but I do find most of > what I do is done with the TT type tooling. Either the early ones > that didn't have the tool changer slot in them or far east ones with a > narrower shoulder that would require modifications for a tool changer. > > The other issue I have with R8 is that some of the tooling allows the > straight section to slide smoothly into the upper part of the spindle. > Other R8 holders barely fit. I'm not sure if the spindle is out of > spec or tooling since they all have the same dimension when I measure > them with a micrometer. > > So that also makes the TT stuff nicer to use. > John > The posibility of a damaged locator pin in the the spindle bore, along with a small variation in the R8 slot width comes to mind. I'd take a decent 1st surface mirror and a good strong light to a good look see at the pin. I'm thinking wear has made it accessible to the drawbolts pull before the pin was engaged. bringing the drawbolt up to tension would then bend the pin upward. It should not be able to rise far enough for the drawbolts threads to engage it before the pin is properly engaged with the slot in the R8.
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) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/gene> _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
