On Sunday 07 July 2013 01:20:43 Jon Elson did opine: > Gene Heskett wrote: > > Now I can > > > > write a peck loop wrapping up the G33.1, that can drive a 10-32 tap > > half an inch into a prepared hole, backing out to clear chips, and do > > it in perhaps 45 to 60 seconds. Each direction change, at 300 revs, > > takes a bit less than 3 seconds for the stop, and accelerate to the > > same speed in the other direction. Listening to the z stepper growl > > seems to say that it is totally and absolutely locked. I have killed > > the motor power in mid cycle, and rolled the spindle by hand, with > > the z drive following it perfectly, as I expected. ;-) > > I do 4-40 holes with a combined drill-tap in about 12 seconds at 1000 > RPM. it takes most of the time doing the drill plunge, then the tapping > only takes a > couple of seconds. I do 10-32 in pre-drilled holes in about 4 seconds > at 660 RPM. Those are single-pass tapping cycles in aluminum. > > Jon
Chuckle, yes, and I can imagine the cost of the tap to do that. I am using what I can get at Tractor Supply, with gullets that wouldn't pretend to have enough room to carry the chip load from a hole that was likely the nearest fractional 1/64th inch size smaller. But you would be amazed at what a 3/32" diameter diamond coated bit, laid in the groove, turning slow enough to not ablate the diamond, used to deepen the gullets by .005" can do for the performance of such a tap. I've also found the usual Ace Hdwe Hansen tap breaks like cast iron today, where 50 years ago it was close to the best you could buy. So today I look for the MIBRO brand, they are not only sharper, but can take 2 to 3x the torque a Hansen tap breaks at. Sure, they aren't a $30 tap from Henly, but they do a fine job for a 7 dollar bill including the right size tap drill. My problem is keeping the tap and the drill together after removal from the blisterpack card. I should make me some box covers for brass storage plates, with the plate having 2 holes drilled in it with each tap drill, and one of then tapped for the tap so they are always together. I'll probably do that right after I find my missing round tuit. :) The best small drill and tap storage ever was the little plastic & cardboard sleeve they shipped rifle ammo primers in 50 years ago. I still have one of those with all my 6-48, 8-40 & 10-32 taps & drills (some of those are carbide) stored in it. Cheers, Gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) My web page: <http://coyoteden.dyndns-free.com:85/gene> is up! My views <http://www.armchairpatriot.com/What%20Has%20America%20Become.shtml> A classic is something that everyone wants to have read and nobody wants to read. -- Mark Twain, "The Disappearance of Literature" A pen in the hand of this president is far more dangerous than 200 million guns in the hands of law-abiding citizens. ------------------------------------------------------------------------------ This SF.net email is sponsored by Windows: Build for Windows Store. http://p.sf.net/sfu/windows-dev2dev _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
