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Author Topic: lathe threading  (Read 4937 times)

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Re: lathe threading
« Reply #10 on: October 22, 2012, 04:23:45 AM »
thanks Hood,
i just started building a controller using Smooth stepper and will use cnc4pc index pulse card and their C25 smooth stepper terminal board hope i can get results like you have. Just one more question, how many pulses/rev are you using from the spindle sensor?

Thanks,
Reg

Offline Hood

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Re: lathe threading
« Reply #11 on: October 22, 2012, 04:41:04 AM »
You can only have one pulse per rev with Mach when using the parallel port, the Timing is no longer an option. As you are using the Smoothstepper I now believe that it can support multiple ppr but I have only ever used one.
Hood
Re: lathe threading
« Reply #12 on: October 22, 2012, 12:20:20 PM »
Hood, did you have to modify the index pulse , as in a pulse stretcher with the smoothstepper?

Offline Hood

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Re: lathe threading
« Reply #13 on: October 22, 2012, 03:31:27 PM »
No, the SmoothStepper can see the  short pulse from an encoders Index no problem.
Hood
Re: lathe threading
« Reply #14 on: April 01, 2015, 05:17:46 AM »
Hood, I'm contemplating going down the Smooth Stepper route and may buy the USB version.
What other boards are available as Break out and Spindle control.
I see that CNC4PC have a terminal board that plugs directly onto the Smooth stepper.

George
Re: lathe threading
« Reply #15 on: April 01, 2015, 10:58:03 PM »
 Thanks Ron Rich and Hood for the response I think I may have explained the threading problem wrong all works wonderful in NSF turn and all works well in threading for 3 to 4 passes then all of a sudden it stops thinks a minute and moves to a new location then starts cutting a new thread in the air it does match up with DRO where ever it stops I did notice today that the RPM fluctuates when it decides to do this I have checked pulse signal and it is working on the board and in mach diagnostics what can make it change its mind in the middle of a thread I read in forum someone edited the G76 macro changed the test False to True can someone explain how and where to do this I am up for any thing.I read Hood you were going to switch to USB is this because of the signal speed and do you think I should..       Thanks Everyone       Axle.

Offline RICH

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Re: lathe threading
« Reply #16 on: April 02, 2015, 05:55:18 AM »
Axle,
See page 47 in Threading on The Lathe  write-up for how to change the M0176 macro. Just provides option to how the code is posted ie; G32 or G76.  Using the G32 will alow easier monitoring of the threading passes. Using g32 or g76
will not fix your problem.

Read the write-up as there are a number of things that account for having problems with threading.
- Mach Version
- Computer Pulse frequency
- Spindle slowdown / Inadequate motor power
- Exceeding axis velocity and acceleration settings for thread to be done
- etc , etc all in the write up

RICH
Re: lathe threading
« Reply #17 on: April 02, 2015, 03:45:03 PM »
I had endless problems threading with a SS and mach 3 till I changed the debounce settings for my spindle index pulse input in the SS settings area.



Been cutting perfect threads ever since.

I would have it run several passes just fine then it would just screw up somewhere, and then attempt to reset itself and it was never right... adjusted the debounce, Voila! fixed.

Chased this problem intermitently for 2 years. drove me nuts.
Re: lathe threading
« Reply #18 on: April 04, 2015, 04:11:41 PM »
Hello Natefoerg,
Can you possibly be more specific regarding the changes you made on debounce setting. Do you remember if you increased or decreased?
Perhaps you could share the current setting that works for you and type of spindle sensor.
Looking to try threading soon and would really like to avoid the "Chased this problem intermittently for 2 years. drove me nuts" part.
Thanks,
Frank