Re: Lathe Threading with DeskCNC

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "John Stevenson" <john@s...>
wrote:

>
> >--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Fred Smith" <imserv@v...>
> >wrote:
> >
> > The DeskCNC lathe threading is now released.
> >
> > The threading is accomplished with a quadrature encoder which is
> > electronically geared to the axis drive. This allows precise
> > threading even with manual rotation of the spindle.
> >
> > For pictures and info, please follow this link:
> >
> > http://www.imsrv.com/cgi-bin/discus/show.cgi?1004/101600
> >
> > Fred Smith - IMService
> > http://www.cadcamcadcam.com/hobby
>
> Fred, Thank you for this link but althouh I understand the setup

your

> description of the process isn't easy to follow. I have searched

for

> some more info but can't find anything.
>
> From the link you state:-
>
> Format for threading:
>
> N99999 G33 X9.9999 Z9.9999 P99.9

If you need product support, I suggest you ask on the DeskCNC user
forum. Our customers that have setup DeskCNC should be very familiar
with the settings as described.

Or is your question really how I generated the CNC threading program?

That was done with a new program called FG4L, which we will be
releasing with our Sherline Lathe Threading kit, probably within the
next week.

> You say X is a diametrical value used for taper threading but

surely X

> is the diameter of the work.
> In the line N100 Z-.75 P32.0 I'm confused as there is no X value

for

> diameter or G33 for the threading cycle.

It's not required since it's not a tapered thread. The G33, works
just like a G01.

> Just as there is no X value I can't see what controls the depth of

the

> thread unless it's a generic value based on 32 pitch ?
>
> You say "Multiple passes were programmed with a 30 degree infeed
> angle" but don't show this. As the info on lathe threading is

scarce

> could you show a full piece of code from setup to end please.

Not a this time.

> "The final cut removed .012 from the diameter" Is this a default
> setting ? as on a 32 pitch 12 thou is an excessive cut for a

thread

> that is only 20 thou deep. Final cut[s] on a thread this size

should

> be just a couple of thou at the most. Doing this in steel will just
> rip the thread up.

This was the diametral adjustment(.012) for the multiple cut
threading pass. The pictured thread was cut and re-cut, 4 seperate
times, each time with an X axis adjustment. The threading, NC
program was run 4 times. The start was correctly picked up each
time and resulted in a satisfactory thread.

Fred Smith - IMService
http://www.cadcamcadcam.com/hobby