ok - that is not rigid tapping. In rigid tapping - the tap holder is rigid - no movement in or out. Emc2 tracks the spindle thru the reversal and back out using a quadrature encoder with index. At all times the axis motion is synced with the spindle.
http://youtube.com/watch?v=JCEwlfJj__A that is a tap held in a Jacobs chuck. (no movement) (and yes - it was done in metal also :)) We wish we would have recorded that. You can read about it here. http://www.linuxcnc.org/docs/devel/html/gcode/main/index.html#SECTION00340000000000000000 Sam ----- Original Message ----- From: "Steve Blackmore" <[EMAIL PROTECTED]> To: "Enhanced Machine Controller (EMC)" <emc-users@lists.sourceforge.net> Sent: Wednesday, October 03, 2007 2:29 AM Subject: Re: [Emc-users] Desktop CNC Website Information > On Tue, 02 Oct 2007 20:57:37 -0500, you wrote: > >>sam sokolik wrote: >>> really - I was in on a converstion with art at the cncworkshop - he had >>> said >>> he thought mach would probably never do rigid tapping. > > He's known to be wrong on occasion <G>. > >>> Could you explain? I could see if you had the spindle setup as a rotory >>> axis... but other than that I have no clue. Maybe some external >>> hardware - >>> doing it outside of mach? (I am not a mach person). > > The spindle is set up as a spindle. The feed/speed is at the thread > pitch for rigid, at 95% pitch for an expanding nose tapping head. > >>Yes, if they use one pulse per rev in a single-channel sensor, >>then Mach can't know which way the spindle is turning. > > It knows because you told it either M3 or M4 - everything doesn't "have" > to be complicated. > >>You have >>to have a quadrature encoder with index to do it properly. And, >>you need much more than one pulse per rev so the Z axis can keep >>up with the rapid speed change when the spindle reverses. > > Define "properly" - I've done it, and somebody else wrote recently they > have been rigid tapping regularly with Mach. Nobody told them they > couldn't - so they did. > > I tap on a regular basis but not strictly rigid fashion - I use an > extending nose tapper "Tapmatic SM4". It works fine. Through hole is > easier than blind hole, but spiral point taps are pretty much essential. > But I also remember all those people, including Art, who told me years > ago that you couldn't do lathe threading with only one pulse per rev ;) > > > Steve Blackmore > -- > > ------------------------------------------------------------------------- > This SF.net email is sponsored by: Microsoft > Defy all challenges. Microsoft(R) Visual Studio 2005. > http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
