More accurate if you turn down the screw heads to make them 0.5mm smaller. In fact if you want all your screws heads to have the same diameter you have to turn them yourself. I looked up tolerances a while ago and it is abut 0.5mm on the head diameter. Likely within a batch they are all the same but if you buy more they high be different. So turn them to the minimum allowed head diameter. I was surprised the tolerance was so wide.
Way did I bother to look this up? I printed a plastic part and the M4 cap screws did not fit in the counterbore. Debugging the problem found the ISO screw standard and the fact that plastic changes as it as it cools. One must allow for both. On Thu, Apr 5, 2018 at 2:28 PM, Gene Heskett <ghesk...@shentel.net> wrote: > On Thursday 05 April 2018 09:26:59 Gene Heskett wrote: > >> On Thursday 05 April 2018 09:20:11 Gene Heskett wrote: >> > On Thursday 05 April 2018 07:56:17 Ken Strauss wrote: >> > > Thanks! >> > > It is probably >> > >> > <https://www.ebay.ca/itm/7-8-R8-COLLET-PII-Precision-Made-in-Korea-N >> >ew -Sealed -Box/292274215740 or http://stores.ebay.ca/jspec1> >> > >> > Word wrapping broke the link, I think I fixed it. >> > Note the arrows now surrounding it. >> >> Nope, a space crept in and broke it again, so use the next link. >> >> > Or, once I found it, pasted from pale moon: >> > >> > <https://www.ebay.ca/itm/7-8-R8-COLLET-PII-Precision-Made-in-Korea-N >> >ew -Sealed-Box-/292274215740?hash=item440ce69b3c> >> > >> > Thats the same price I paid. But I see this sale claims .0005" TIR. >> > The sale I bought from claimed .00016" TIR. >> > >> > I've made mounting pillows for the ER-40 adapter I bought for the >> > lathe, an r8, chucked in an er-40 collet, with a 7/8" slug in the >> > r8, and pulled about 50 thou into the ER-40 collet, seems to be a >> > good grip. >> > >> > The pillows, made from Mahogany, cut into end grain, but before I >> > clamp it down, I'm going to glue on some oak or ash strips under the >> > cutout to help prevent the mahogany from splitting because it will >> > have a tight grip. Hopefully that will allow a carbide tool to make >> > the slot for the m4 socket head bolt that should lock the brass tap >> > carrier slug from rotating in the R8. The one I tried prior, the >> > whole thing slipped on the table, but it looks as if the carbide >> > tooling can cut it once I get it mounted firmly. I cut into the end >> > grain because that direction should offer the best crush resistance >> > when I tighten the rest of the clamps down. Theoretically. And a >> > heck of a lot easier than carving up a huge block of more $ alu. > > Got the braces glued on, gave the titebond III an hour to get a grip and > finished the Grizzly 7/8 R8 so its usable, but when I switched it out > for the first of the Korean ones it sounded different when the tool > touched. Went ahead and drove the machine with what should have cut a > 7mm wide "key", but when testing for fit, the screw head was half a mm > bigger than the cut. Stopped the spindle, and the leading edge of the > flutes of a 3 flute, very high twist SC mill I had sourced from ebay a > few months back as part of a 2-4-6-8mm kit for about a $20 bill, were > all shattered away for about a mm back from the edge. I can finish the > cut with a dremel, but these things are HARDENED. And I only have US > sourced 1/4" 4 fluter's left. I'll go waste one of those. Or finish it > with the die grinder, then try one of my 1/4" 4 fluter's on #3. > > Which just proves that nothing is ever as simple as it appears... > > EDM maybe? I can do that too, on the little mill. > > -- > 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 -- Chris Albertson Redondo Beach, California ------------------------------------------------------------------------------ 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
