On Wednesday 21 May 2014 10:30:44 Kirk Wallace did opine And Gene did reply: > On 05/21/2014 05:07 AM, Gene Heskett wrote: > ... > > > raising the squeak to several kilohertz. So most of my threads are > > 40 to 50 pass, 5 to 10 minutes runtime affairs, to get a decent > > looking thread. > > For a thread of that size (19,5 mm), make J about one quarter to one > third of K, maybe even half in aluminum. One needs to take off enough > material to get the tool below the surface. This should give five to > three passes before any spring passes which I would not bother doing. > Otherwise, I'd use a tool post grinder with many passes.
No doubt good advice Kirk, but the flex in the tool bends it down to where the cut depth is controlled by the clearance below the cutting edge which I purposely leave very little of. Then it decides to cut and springs back. That of course leaves a very poor quality thread, with crap sticking out you can paper cut yourself with. Sometimes I can reduce the singing by a quick resharpening of the tool. But its likely going to come back as soon as its making chips. This isn't helped in the present setup as the jaws are turned around, which forces me to extend the compound such that there is no saddle support under the cutting tip. I normally keep it pulled back far enough so the downforce from the cut is back of the front edge of the saddle. I think today that I will uncouple the apron (the same 2 screws that held the original apron) and pull it toward the headstock to gain access to the bit of steel they optimistically call a gib, and see if I can tighten it a degree or so to take up the play at the back of the saddle. Its super ultra critical as there isn't a lot of weight on the v-way. It would have helped if I had made the new apron to carry that ballnut out of steel. The weight would I think help since the motor, a 425 oz, is hanging off the rear of the crossfeed. Lots more weight on the back, flat of the bed than on the v-way. 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> US V Castleman, SCOTUS, Mar 2014 is grounds for Impeaching SCOTUS ------------------------------------------------------------------------------ "Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE Instantly run your Selenium tests across 300+ browser/OS combos. Get unparalleled scalability from the best Selenium testing platform available Simple to use. Nothing to install. Get started now for free." http://p.sf.net/sfu/SauceLabs _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
