I have cut threads that way. the tooling http://www.collection.archivist.info/archive/DJCPD/PD/2009/2009_08_13_cnc/P1010245.JPG
I also tilt the rotary axis so the cut properly follows the helix, this requires some maths in the gcode to follow the tilted path before I made that tool and also before the B axis I made a worm jacking the rotary to the required angle with some packing http://www.youtube.com/watch?v=Jbp8SJ9RxqI Dave Caroline On Mon, Dec 26, 2011 at 8:00 AM, gene heskett <ghesk...@wdtv.com> wrote: > Greetings; > > I've about worn out that 7x10 I have, and its rubber tool post prevents me > from doing anything resembling a fine finish regardless of the sharpness of > the bit. When cutting threads I have to, before reversing the spindle to > back away & reset to deepen the cut on the next pass, back the crossfeed > off a full turn to keep the bit from dragging on the thread as it > supposedly retraces its path backwards. I knew it was a toy when I bought > it, and I'm considering its replacement with something big enough that its > worthwhile cnc'ing it. > > I have a need for cutting a clean, nearly interference fitted 1/4x28 > external thread for a distance of about 1/4", immediately adjacent to a > 1/2" diameter seating plane when this is screwed into its receiver. > > I don't have an encoder on either the lathe or the mills spindle, so the > thought runs toward a flying cutter in the mill spindle whose tip profile > is that of the 60 degree included angle tooth. > > Now, the cutter would be working on the side of the workpiece, mounted with > the axis vertical in a chuck on a rotary table, turning very slowly as the > z axis travels in 1/28 step. > > Since I can run the z axis and a axis in lock step, what prevents me from > cutting this thread with the fly cutter other than finding a suitable fly > cutter? > > I thought so, so where in tunket can I find such a fly cutter that is > actually holding a single point threading insert, perhaps an inch in > diameter overall. Googling hasn't found such a beast at less than 3" in > diameter and many BIG bucks cost. Or is this just another tool I'll have > to make, in which case it will be holding a less easily fractured square > piece of HSS tool steel, not a carbide chip. > > Or is this just another idea I should forget because I'll not be able to > hold an edge on the HSS tool because of the impact of its striking the > workpiece and taking off a thou or less per revolution? > > Thanks guys. > > 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> > Now I lay me down to sleep > I pray the double lock will keep; > May no brick through the window break, > And, no one rob me till I awake. > > ------------------------------------------------------------------------------ > Write once. Port to many. > Get the SDK and tools to simplify cross-platform app development. Create > new or port existing apps to sell to consumers worldwide. Explore the > Intel AppUpSM program developer opportunity. appdeveloper.intel.com/join > http://p.sf.net/sfu/intel-appdev > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ Write once. Port to many. Get the SDK and tools to simplify cross-platform app development. Create new or port existing apps to sell to consumers worldwide. Explore the Intel AppUpSM program developer opportunity. appdeveloper.intel.com/join http://p.sf.net/sfu/intel-appdev _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users