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Probe not stopping "Z" axis
« on: October 19, 2017, 11:39:02 AM »
Hi,

I have had a few issues with my new CNC I built mostly getting to run and Limits and Homing etc.

My problem for this thread is the probe does not stop "Z" axis from going down, in Mach3 Diagnostics when the probe is touched the switch is triggering the Digitize Yellow LED but "Z" does not stop only after hitting limit switch does it stop.

My other issue is X and Y axis are going in a negative direction on the DRO and if I try and run say roadrunner from Home position it just hits limit switches.

Regards John
Re: Probe not stopping "Z" axis
« Reply #1 on: October 19, 2017, 05:27:31 PM »
Hi,
not sure about the probe problem at the moment.

Try reversing the X and Y axes by checking (or unchecking as the case my be) the active low setting of the
DIR signal of both stepper drivers.

Craig
My wife left with my best friend...
     and I miss him!
Re: Probe not stopping "Z" axis
« Reply #2 on: October 19, 2017, 11:28:44 PM »
Hi John,
just double check that you have assigned the input Probe to a valid pin. What port and what pin?

It may be that the Digitize LED is confusing you, I think (I'm not near a machine) Digitise is actually an output.
Hopefully just a confusion in terms.

Craig
My wife left with my best friend...
     and I miss him!
Re: Probe not stopping "Z" axis
« Reply #3 on: October 20, 2017, 01:49:04 AM »
Hi John,
my apologies it is my confusion not yours. The LED on the diagnostics page is called Digitize but on Machs inputs page its called Probe.

Craig
My wife left with my best friend...
     and I miss him!
Re: Probe not stopping "Z" axis
« Reply #4 on: October 20, 2017, 08:31:09 AM »
Hi Craig,

Thanks again for help think I am getting there slowly a lot more difficult that I imagined, sorted the +ve and -Ve directions of movement, combination of Zero axis and then find machine axis is different so turning motors off and driving to zero sorted that problem tried setting soft limits seem to get that working, but then I tried running road runner and the first Z command is G0 X0  Y0  and Z  0.2 this drives my "Z" axis to stops as setting is 0.0000 going down to about -2.24 inches, when I get past that it runs so far think it stops after so far as I think that could be I only got Demo copy till I am happy that I can handle the program. >:D >:D >:D >:D

The probe is assigned to pin 11 and when I touch the probe the Digitize LED in "Input Signal current State" lights up all the other limit switches work fine and LED's work.

Pic of BOB so you can see the connections on LH Side.

Regards John
Re: Probe not stopping "Z" axis
« Reply #5 on: October 20, 2017, 09:41:04 AM »
Hi John,
this is called 'CNC', the first letter stands for 'computer', when in your experience have anything to do with computers gone smoothly?

Probing is done with a G31 code. How is that code generated? Can you post a sample of it?

Craig
My wife left with my best friend...
     and I miss him!
Re: Probe not stopping "Z" axis
« Reply #6 on: October 20, 2017, 10:45:55 AM »
Hi Craig,

Sorry for terminology but its not a CNC till it works properly LOL.

Am I telling you the wrong thing, its a Probe which sets the hight of the "Z" axis prior to starting a job i.e clip on drill or router and when point touches the metal plate it stops the "Z" axis.

Also don't know what I touched but suddenly changed to metric, I set to inches, how do I change back.

Regards John
Re: Probe not stopping "Z" axis
« Reply #7 on: October 20, 2017, 11:21:11 AM »
Think I found out why got the change to metric, I loaded "Ball.tap" and the first line gives a G21 which quote "G21 at the start of the code will tell Mach its metric, G20 will tell Mach its Imperial"  so think thats my problem need to get a G20 code to reverse it.

Regards John
Re: Probe not stopping "Z" axis
« Reply #8 on: October 20, 2017, 01:49:26 PM »
Hi John,
yes G21/G20 changes units and its modal. So if a G21 is issued the machine will interpret all motion codes as mm and stay that way UNTIL a G20 is issued.

Quote
Am I telling you the wrong thing, its a Probe which sets the hight of the "Z" axis prior to starting a job i.e clip on drill or router and when point touches the metal plate it stops the "Z" axis.
Yes this is one of the most common of the probing procedures. A G31 code is issued to cause the probing cycle. Can you post the G31 code that you are using?

Craig
My wife left with my best friend...
     and I miss him!
Re: Probe not stopping "Z" axis
« Reply #9 on: October 21, 2017, 06:19:30 AM »
Hi Craig

Yeh didn't quite understand the reason of G31 code, but yes that activates the probe to work, I found another thread on this forum and tried "G31 Z-4 F40" and yes it does the job.

I think I can call it a CNC know, gonna try the spindle motor today, But, I'm gonna have to do a few mods to "X" axis and Gantry its not stable enough, got more bits on order "wife would kill me " if she knew what i spending LOL

Very grateful for all your help.

Regards John