On Monday, January 16, 2012 04:35:12 PM a...@conceptmachinery.com did opine:
> > a...@conceptmachinery.com wrote: > >> Hi > >> i there spindle motor and motor drive that can be better used for > >> tapping? > >> Problem with use tap is that spindle motor can easy crash tap and > >> after that extra charge - + equipment - to remove broke tap from > >> hole. > > > > I have been using rigid tapping with EMC2 for almost 2 years. It > > works amazingly well. > > You do have to be sure the tap will not reach the bottom of the hole. > > There is no system > > I can think of that can stop the motor quickly enough if this happens, > > and even using > > a torque-limiting clutch will not prevent all catastrophes. > > Hi > Tapping cycle use very slow motion, why drive can not stop motion of > spindle? if max rpm for tapping around 100 rpm , can drive stop spindle > ? it is possible to program for 70% or torque that actually will crash > tap, to have some safety. > aram I don't have the power to drive a tap much bigger than 4-40 here. As for detecting the imminent tap breakage, it takes maybe 100ms to begin to effect an estop on my dc spindle, and my suicide breaking stop load is such that the spindle would coast from 1/4 to maybe 3/4s of a full turn after the estop came on at 100-150 rpms. It is quite rapid, but I wouldn't want to damage the magnets in that PM field motor by throwing a dead short across it when at full motor revs either. In short, the mechanical slip clutch would IMO, be the better idea, much much less mass to stop even if the spindle is still going. Then the problem is to stop the z drive before it drives the tap on thru the hole, stripping the threads or worse. The only way to do that is to encode the tap holder so the z drive is driven by the taps actual rpms. I have seen spring loaded tap drivers for sale that would cushion that, but don't recall where now. But I've no clue if anyone has attempted such a specialized feat yet. Probably the spring loaded tap holder is the most used if anything is used. > > Jon > > > > ---------------------------------------------------------------------- > > -------- RSA(R) Conference 2012 > > Mar 27 - Feb 2 > > Save $400 by Jan. 27 > > Register now! > > http://p.sf.net/sfu/rsa-sfdev2dev2 > > _______________________________________________ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > ------------------------------------------------------------------------ > ------ Keep Your Developer Skills Current with LearnDevNow! > The most comprehensive online learning library for Microsoft developers > is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3, > Metro Style Apps, more. Free future releases when you subscribe now! > http://p.sf.net/sfu/learndevnow-d2d > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users 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> A horse breeder has his young colts bottle-fed after they're three days old. He heard that a foal and his mummy are soon parted. ------------------------------------------------------------------------------ Keep Your Developer Skills Current with LearnDevNow! The most comprehensive online learning library for Microsoft developers is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3, Metro Style Apps, more. Free future releases when you subscribe now! http://p.sf.net/sfu/learndevnow-d2d _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
