Hello Guest it is December 08, 2019, 05:48:07 AM

Author Topic: touch probeing  (Read 507 times)

0 Members and 1 Guest are viewing this topic.

touch probeing
« on: February 24, 2019, 05:48:54 PM »
Hi
I have a wireless height setting gauge for setting tool height  the probing function works well but is inconsistent because of Z axis over run I believe
Even when the feed speed is really slow though when slow it is not so pronounced  I would like to modify it so it is like the home limit switch  these find the switch then slowly back away till the switch turn back of
I have found the scrip for the touch probing but do not know how to fix it so it triggers on the retraction and set the height from that point
has any one done this and can help
Regards Ray
Re: touch probeing
« Reply #1 on: February 24, 2019, 06:11:06 PM »
Hi,
what motion controller are you using?

When Mach executes a G31 probing move the motion controller detects the probe touch event and stops all motion.
Motion controllers are very fast so unless you are approaching at a ridiculous seed there should little or no
overrun.

For example I have an ESS motion controller and when probing at 100 mm/min (no fast but not really slow either) the
overrun is less than 1 um (0.78um).

It sounds to me like the probing code you are using is relying on Mach to detect the probe event. In that case the motion
controller will propagate a signal back to Mach, Mach will generate a stop signal and send it back to the motion controller
to execute. The 'around the loop delay' could easily be 1/20 sec whereas a good motion controller will detect and stop
motion within a few tens of micro seconds.

What code are you using to probe?

Craig
My wife left with my best friend...
     and I miss him!
Re: touch probeing
« Reply #2 on: February 24, 2019, 07:04:27 PM »
Hi
I am using a screen that came with mach4 and has a touch button that takes me to a new probing screen   but
i only use the z axis probe if I could get to say 3 to 5 micron accuracy I would be home and hosed
I will have a play with the G31 in the MDI   could you help with a bit of code for the z axis to run in the MDI
Regards Ray
Re: touch probeing
« Reply #3 on: February 24, 2019, 07:06:15 PM »
Hi,
what controller? Its the controller that does the business not Mach.

Craig
My wife left with my best friend...
     and I miss him!
Re: touch probeing
« Reply #4 on: February 25, 2019, 12:17:52 AM »
Hi
I have a ESS controller but and it is a big BUT  the height gauge is a XHC wireless gauge I did some tests with G31 and 4 times out of 10 comes to almost exactly  repeatable  the other 6 times up to almost 1mm  .040" difference and I think it is the height gauge being flaky I can see the difference in height and with G31 could slow the feed   right down this made it better but still not good  or repeatable
I will try  another height gauge any idea's of a good brand I had a bunch of problems with a XHC controller  that was not a good experiance and maybe the height gauge is not much better
Regards Ray
Re: touch probeing
« Reply #5 on: February 25, 2019, 01:27:40 AM »
Hi,
I use the ESS and have no problems with overrun, I suspect you are correct about XHC.

If you've read any of my posts you will know I hate XHC with a vengeance. I am NOT a disinterested observer.

I don't have any recommendations excepting the obvious.....Reinshaw and/or Heidenhan!!!

Craig
My wife left with my best friend...
     and I miss him!

Offline smurph

*
  • *
  •  1,153 1,153
  • "That there... that's an RV."
    • View Profile
Re: touch probeing
« Reply #6 on: February 28, 2019, 07:37:15 PM »
Blum makes a good line of probes/tool setters too.  None of the good stuff is cheap, unfortunately.

Steve
Re: touch probeing
« Reply #7 on: March 01, 2019, 12:17:04 AM »
These are pretty good.
eBay item:  143067989514
Chad Byrd

Offline thosj

*
  •  368 368
    • View Profile
Re: touch probeing
« Reply #8 on: March 01, 2019, 09:35:23 AM »
Hey Chad,

Just out of curiosity, what's that little side thingy on that tool setter you linked? I almost bought one to find out, still might!!!

Tom
Re: touch probeing
« Reply #9 on: March 01, 2019, 09:45:07 AM »
Its an air nozzle.  You can hook up an airline to blast the chips off of the top of the tool setter.  Pretty cool idea really, just hook up a solenoid to it.
Chad Byrd