On 19.05.18 21:41, Gene Heskett wrote: > I have all these brass slugs fixed so they are keyed into a scallop in > the edge of a 7/8" R8 collet that fits the head of a 4mm capscrew in the > lower end of the slug. So the next operation is to set it into the > spindle, and position it so the rotation center is directly over the > drill bit, chosen to be a fairly wiggle free fit on the shank of the tap > that will be held in this one. > > Good idea but the drill bit doesn't seem to want to self center, despite > moveing the table and the drill bit around looking for the magic spot. I > haven't tried a small center-drill yet. Is that the fix, or do I need to > treat the bit in a drill doctor? Or both?
Aligning the tailstock on the lathe seems worth doing, Gene, but if you need some taphats beforehand, then a small center-drill is the answer. I don't drill a hole on the lathe or mill without center-drilling first. It's not worth it as a .243 aimed from across the street is more precise. ... > But how best to prevent the drill bit from doing the sailors hornpipe > dance when the brass first touches it? Thats the $64 question. You can get quite a few small center-drills for $64 - a lot less of the medium & bigger ones. But ISTR that the good ones are cobalt steel, and that's why they do fine even in SS, I find. Erik ------------------------------------------------------------------------------ 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
