On Friday 11 May 2018 03:32:39 Erik Christiansen wrote: > On 11.05.18 01:25, Gene Heskett wrote: > > On Thursday 10 May 2018 22:23:56 Erik Christiansen wrote: > > > But, whoa. I'm also not fully across the need for bore adjustment. > > > As taps are ground from a few stock sizes, only those few sizes of > > > tap hat bore are needed. While I found a drill close enough for > > > one size, and bored the other, if I had to make a bunch of the > > > latter, I'd probably make up a D-bit reamer, and keep it with the > > > tap hat kit. > > > > Looking at my tap collection, I'd guess it will take not less than > > 10 different drills to bore the thru holes to fit the tap shanks. I > > have a very mixed origin tap collection, And the metric stuff all is > > Chinese, quality from junk to very good. > > Hmmm. Then I'd bore the odd ones to size ... when I needed 'em. Just > keep enough brass sleeves to hand, drilled out enough for the small > boring bar to go in. > > > And I'm trying to dream up a way to mill a square in the rear, where > > the square but of the tap will be, and since I have one of those > > kilowatt induction heaters, figure out how to pour a lower melting > > point alloy of some sort to fix the square tap butt into the square > > in the rear of the brass holder, as thats a bunch easier than all > > that drilling and tapping for set screws. High silver alloy solder > > comes to mind as its some pretty tough stuff. But would that heat, > > maybe 850-900F kill the tap? > > Urrgh. Wet flannel around the business end of the tap ought to protect > against the brutality inflicted on the other end, but there are better > ways to skin a cat than with a flamethrower. > Chuckle. I figure thats the best test to find out if the cat is really dead though.
> How's this size up?: Radially slot the top end of the tap hat body to > provide two internal flats to grip the tap square, then drill/bore > from the other end to take the tap. If you overshoot, then the middle > of each flat will go, but the outer third or so on each side will > remain unless the square end of the tap has been made unnaturally > small. I don't have a tap whose diagonal across the square isn't a few thou smaller than its shank. > But hold on, what keeps the tap captive then? I'm sticking with > the grubscrews. > > > If I do the set screw thing, I'll need them in 2mm to 6mm, or maybe > > even 8mm for the biggest ones. > > Well, you could MIG tack weld the top of the taps into steel tap hats > - that wouldn't conduct much heat to the other end, but that's rough > treatment too. A box or three of grubscrews off fleabay won't add up > to much cost. The last boxful I bought was M3 to M10, IIRC. You might > do better buying plastic bags of each size, for quantity. > Thats what I'm going to do, something with a bit of length so an allen or bristol wrench has a decent chance of driving it well. I just need to get off my duff and get a few boxes ordered. 100 count boxes. > > Thats not counting a 20 kg bag of 1.5" to 4"ers for pipe I found > > while cleaning up the old home place after Dee's brother died. None > > in good shape, broken teeth etc. He worked for one of the local gas > > companies as a mech at a pumping station. > Rigid tapping with the 4"er might challenge the machine ... not least > getting the job under the spindle, I figure. Challenge the machine? Understatement. Stall the motor and break the plastic gears. And I've not seen a set of metal gears to fit the g0704 being offered. > > Stay warm Erik, it should be getting toward keeping the wood stove > > crackling in your neck of the woods. Its been up as high as 89F here > > already. > > The hills here are smaller than yours (I'm only at 600' altitude), but > with 40F less than at your place, the heater's earning its keep > already. > > Erik I'm not that high either, 1000-1100' maybe. The "mountain" our old ntsc transmitter is on since 1955 or so, is called Fisher Hill, 1620 feet at the base of a 509' tower and antenna. Costs more to take it down than its worth as salvage, so they are keeping the lights on. I'm the light watcher/failure reporter as I can see it from my place. :) -- 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
