Picture of Mach3 Zero Probe Tool
Controller PIN Out.PNG
Controller Connection.jpg
2013-09-06 19.51.51.jpg
2013-09-06 19.57.03.jpg
This is a Simple Guide on how to use a Probe Tool in Mach 3 to find the exact top of a material.
You can use an input on your CNC Controller, but if you don’t have free inputs because they are used for Limit Switches like in my case. You can just get another CNC Controller when you have an Additional LPT Port, and if not they are very cheap.

I have attached a LED on my Probe, but it has no function other than a visual indication. So the Resistor and LED it not needed.  Just a wire and a Metal block will work as well.

What I used is :
A very CNC Controller from eBay for 12$ (5 Axis CNC Breakout Board For Stepper Driver)
You just need a free Input Port on your Controller.

This VB Source code for the Probing Tool.
'VB Code Start
CurrentFeed = GetOemDRO(818)

ZMove = 20.00 'Total lenght of Probe to move before Stop or no Contact Made.
ZOffset = 1.60 ' Plate Hight
ZSal = ZOffset + 2.00 '+ Free Hight, Will possition the Proble 2 MM over the Material.

StopZmove = 0
If GetOemLed (825)=0 Then
DoOEMButton (1010)
Code "G4 P2.5"
Code "G31 Z-"& ZMove & "F25"
While IsMoving()
Probepos = GetVar(2002)
If Probepos = - ZMove Then
responce = MsgBox ("**ERROR** " , 4 , "Probe **ERROR**" )
Code "G0 Z10"
StopZmove = 1
Code "F" &CurrentFeed
End If
If StopZmove = 0 Then
Code "G0 Z" & Probepos
While IsMoving ()
Sleep (200)
Call SetDro (2, ZOffset)
Code "G4 P1"
Code "G0 Z" & ZSal
Code "(Z zeroed)"
Code "F" &CurrentFeed
End If
Code "(Check Ground Probe)"
End If
Exit Sub
'VB Code Stop

kiark5 months ago

Thanks for the script, everything works fine, but when the drill touches the probe the Z-Axis moves down (into the probe) before it moves back up... i fortunately tried it all holding the probe in my hand ;)

Thanks for the script, very helpful.

suli25an1 year ago
Dear Sir.
Thank you for this good explanation, but even more, how to connect, Mach3 Zero Probe Tool, in the control box.
marzouin1 year ago
Hi nice tutorial !