Messages

1

General Mach Discussion / THREADING

« on: November 24, 2015, 08:34:07 AM »

Hi-
Just a general question on threading.    I know Mach 3 starts the spindle when it receives a pulse from the spindle sensor and that assures that the pass always starts in the same rotational position of the part.  As the cut progresses, does Mach 3 adjust spindle rpm to maintain the proper ratio to carriage travel, or does it adjust the carriage feed rate to match the spindle rpm? 

Thanks MM

2

General Mach Discussion / ADJUSTING PID SETTINGS FOR SPINDLE CONTROL

« on: August 08, 2015, 12:40:06 PM »

I am  having trouble understanding the PID settings for spindle control.  I am running a 2HP VFD drive and Gecko 540 controller. I have magnetic sensors on my spindle pulleys.  I can get my spindle within 5% of the commanded speed for normal work. But when threading, my cutter gets out of place and begins to wipe out my previous passes.  It seems that the PID is somehow calculating an error each pass and changing the start position of the cutter to compensate for this error in the RPM.  I found that if I manually set the RPM with my laser tach, then plug that value into the Mach 3 threading wizard, it cuts perfectly.  I just don't understand how to adjust the 3 settings in PID to sort this out.

3

General Mach Discussion / Re: Mach turn wizard

« on: October 18, 2014, 07:40:51 PM »

Hood,
Thanks, I finally  came to that conclusion- maybe in the coding it is adding the clearance to both sides of the part.  I was still getting the double cut error, and after trying about everything by trial and error, I found 2 issues
1.  If Jog is turned on it wants to cut double
2.  If backlash compensation is turned on it seems to double the backlash value of X when in diameter mode.
Once I turned those 2 items off I was getting cuts accurate within the range of the machine back lash.   My next plan ( after resting my feet) is to cut the X axis backlash setting in half and see if that works.

4

General Mach Discussion / Mach turn wizard

« on: October 16, 2014, 07:05:36 PM »

Hi- I'm new to the system.  Trying to turn a simple diameter using the mach turn wizard.  I am in diameter mode and absolute positioning.
I set my clearance to 0.012", but the wizard doubles the amount to 0.024" in the G code.

EXAMPLE   X start is 0.755  X end is 0.725  Clearance is 0.012

When the code posts it shows the X position as 0.779 instead of 0.767

When I run the program it also cuts double and my part ends up at 0.695
It's clear that X is travelling twice as far as it should, but I can't understand why.

Thanks in advance for any help