On Thursday 13 July 2017 20:44:44 dave wrote: > On 07/13/2017 06:38 AM, Gene Heskett wrote: > > On Thursday 13 July 2017 07:27:35 andy pugh wrote: > >> On 13 July 2017 at 01:01, Gene Heskett <[email protected]> wrote: > >>> Greetings all; > >>> > >>> I have rx'd a 6" scale with a remote readout, made by Shars, or at > >>> least resold by Shars, with the intention of putting it on my > >>> Sheldon's tailstock. > >> > >> Instead of that, why not CNC-drill with the toolpost? You get > >> peck-drilling and accurate depth that way. > > > > True Andy, but I'd need a truly aligned hole in the table to support > > the workpiece, which is a stainless steel rod, already bored thru > > lengthwise and cut rifled, with the ability to locate that bore to > > microinch accuracy. Oh, and I forgot, the hole in the table would > > need to be a bit over 30" deep. > > > > IOW, this is a lathe job. > > > > Cheers, Gene Heskett > > Please allow me to attempt to draw a verbal picture related to what I > thought Andy was saying > Mount a decent or indecent piece of steel on the crossfeed, large > enough to allow for a collet. > I'm thinking 5C or 16C. With a drill mounted in the chuck drill a > starter hole. Mount a boring head > in the chuck and bore dia for your choice of collet. Back out and do > the taper. Make yourself > a nice brass or bronze nut to affix the collet(s) in the holder. This > can now hold very long drills > for drilling for barrel inserts, reamers as appropriate, boring > heads,boring bars, etc. Your X zero is as good as your measuring > system and mechanics, ditto with Z. You can shim up if necessary to > align in Y: or grind a bit off the bottom of the block. It is as > stable and stiff as your cross-slide. > > Hope this is useful; I certainly have found it so. > > Dave
I've done similar ops on TLM, with varying degrees of success. But a boring head is still on my list of tools to acquire. Chambering reamers need to be float mounted but restrained from rotation, and those mounts generally are tailstock inserts needing little red wagonloads of money to put them on my real estate. The float mount is so they are self-centering in the bore for best accuracy. OTOH, I've used the Ackley-06 reamer 3 times now with the barrel still mounted in the action. I had an 8 point socket, 3/8" drive, whose OD was about 3 or 4 thou smaller that the bolt bore, cranked it with a 3/8 speed handle, checking headspace with a previously fireformed case. Tedious, but worked very well as I was able to get a headspace fit that may have been .0005" shorter. Unfortunately, that socket left along with a toolbox, in northern CA, in 1982. I haven't seen another like it since, or it would have followed me home. Cheers Dave E., 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
