Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: john_bry on July 08, 2012, 09:56:36 PM

Title: Threading
Post by: john_bry on July 08, 2012, 09:56:36 PM

Im trying to understand how its possible to cut threads without stopping the spindle.

The x feed rate and spindle rpm must be related and then you just pull out of the cut
go back to start, feed in a little bit more and your good to go?
How do you know your starting the next run at the same place the thread started.

Right now, Im doing a controlled number of  revolutions stop the spindle  reverse and retract out the same way.
Feed in some more and redo.

Thanks

Title: Re: Threading
Post by: RICH on July 08, 2012, 10:19:10 PM

JOHN,
Mach's CNC threading cycle is described in Threading On  the Lathe  which can be found in Members Docs.

RICH

Title: Re: Threading
Post by: Hood on July 09, 2012, 10:44:20 AM

Single point threading with a CNC lathe is just like threading with a manual lathe in the respect that the spindle doesnt stop  between passes, there is no need as the only thing that needs to be in sync is the Z axis to the spindle speed. On a conventional lathe that is achieved by mechanical gearing and engaging the half nut at the correct time at the start of each pass. On a CNC lathe the controller does that by watching the Index pulse and starting the Z axis at the correct time.
Hood