Re: CNC lathe threading?

["Bob Hiller -1" <aoklans-at-tir.com>]

So, any pro's, con's on the Shoptask 3 in 1? I am looking for a
Multi-Purpose Machining center but have never heard of the Shoptask 3 in 1.

Thanks,

Bob Hiller

----- Original Message -----
From: "Tim Goldstein" <timg-at-ktmarketing.com>
To: "Multiple recipients of list" <emc-at-nist.gov>
Sent: Tuesday, March 11, 2003 12:20 PM
Subject: RE: CNC lathe threading?


>
> I am also a Shoptask 3 in 1 owner.
>
>
> TurboCNC ( www.DAKEng.com ) has treading capability built in. I have not
> tried that function, but reports I have read seem to indicate it works.
>
> Tim
> [Denver, CO]
> Sherline products at Deep Discount
> Mach1 & DeskCNC with credit card ordering
> www.KTMarketing.com/Sherline
> Now selling Visual Mill
>
>
> > -----Original Message-----
> > Funny, I have a shoptask 3 in 1 as well.  Back to threading...
> >
> >
> > I tried writing a g code program that would just cut the
> > threads with multiple passes assuming a particular machine
> > RPM.  The problem that I ran into is that EMC doesn't seem to
> > have a constant time between task starts, even if I set
> > bridgeport CYCLE_TIME to 0 and others to 0.001 and no machine load.
> >
> > I've now "discovered" emcsh.  I've modified the code to cut
> > the threads based on an assumption of constant spindle RPM.
> > It cuts a pass by sending MDI commands out.  After the pass,
> > it just does a
> > (while(ewait() != the_right_time +- some_small_number)) then
> > sends the MDI code for the next pass.
> >
> > I'll use it like this :
> >      start up tkemc
> >      get the machine running
> >      at a command prompt, type "thread -r machinerpm -d
> > thread_depth -t tpi..."
> >      Then watch the tkemc gui follow the thread cutter's commands
> >
> > I'm going to see how that works today with very low spindle
> > RPM's (120).  I've already ordered a hall effect sensor in
> > case that doesn't work.  I figure I'll modify the above code
> > to watch a parallel port input pin for transitions, calculate
> > the feed rate based on it, then start the MDI code threading
> > passes by clocking on the magnet.
> >
> > RT-linux is what's giving me the most trouble.  It's not
> > nearly as simple as some other RTlinuxes.  Could anyone out
> > there give me an example that will run emcsh at a real-time
> > priority so I can translate it to my thread cutter?
> >
> >    On a positive note, it's really awesome how emctask,
> > bridgeportio, etc are all separated and communicate.  It
> > makes it really nice for someone like me who wants to get in
> > the middle and play with things.
> >
>
>
>