Auto Z & Corner Finding Touch Plate [Archived]¶

Please Note

If you are using Mach4 CNC controller software, refer to the Mach4 Auto Z and Corner Finding Touch Plate Instructions in our Mach4 Users Guide.

If you purchased one of our Plug and Play CNC Control Systems, Steps 2-4 below are automatically performed for you when you use our latest Mach3 installer and XML configuration files (version 19.2 or later). Please refer to the Mach3 CNC Software Setup Guide for more information.

Using the Auto Z and Corner Finding Touch Plate with Mach3

Setup of the Auto Z and Corner Finding Touch Plate is fairly straight forward:

Plug in the unit
1. For our CRP800 Plug and Play CNC Control Systems (both NEMA 23 and NEMA 34), just plug the M12 connector from your touch plate into the appropriate input for configuration file your are using:
  1. For our revision 19.2 configuration files, use the "Aux 2" sensor input (Port #2, Pin #8)
  2. For our revision 16.1 - 18.3 configuration files, use the "Aux 1" sensor input (Port #2, Pin #9)
  3. For earlier revisions of our XML configuration files, use the "Z" sensor input (Port #2, Pin #6)
  4. In either case, you can use a different AUX port if you prefer, although you will then need to re-assign the pin used for the "Probe" function.
2. For older PMDX-126 based NEMA 34 systems, just connect the two leads on the unit to "Signal" and "Ground" on one of the 3 pin connectors supplied with your panel, and plug into the red input signal board. NOTE, the "Ground" should be the lead connected to the magnet (or clip on older models), while the "Signal" should be the lead going to the brass puck on the touch plate.
3. For a DIY system based on the PMDX-126 breakout board, just connect the two leads to an input pin and a common on J11.
4. For a G540 based system, you will need to wire one of the leads to an available input (pins 1 through 4 on the G540), and the other lead to the G540 power supply common (V-, on pin 12 of the G540). NOTE, the V- connection should be the lead connected to the magnet (or clip on older models), while the input pin should be the lead going to the brass puck on the touch plate./li>
Set up the input pin for the "Probe".
You will need to configure the probe as an active low input on an available open input. The example below shows pin 15 being used, but if you are already using pin 15 for something else (such as a limit switch or estop), you will need to use another available input.

If you have a CRP800 Plug and Play CNC Control Systems, the probe input should already be set up on Port# 2, Pin# 9 (tied to the "AUX 1" input on your controller), or Pin#6 (in older revisions of our configuration files, tied to the "Z" input on your controller).

Any changes to pins are made from the Config -> Ports and Pins -> Input Signals tab.
Test the input to ensure proper function and pin assignment.
If you have an Ethernet Smoothstepper (pre-installed in most plug and play packages), go to the diagnostics page under Plugin Control->ESS Data Monitoring. From this menu, you should be able to see an input signal toggle (check mark turn on and off) when you touch the magnet (or clip on older models) to the brass puck of the touch plate. If you do not see the same signal toggling that you assigned to the probe input, you should go back and re-assign the signal. If you do not see a signal toggling at all, contact us before proceeding further.

Add the Visual basic code to the "Auto Tool Zero" button.

Go to the Operator menu and select "Edit Button Script"; the configurable buttons on the page will start flashing.
Click on the "Auto Tool Zero" button; this will bring up a window with code you can edit.

Copy the code below into the editor (replacing any existing code):

' Auto Z and Corner Finding Touch Plate Script version 1.2 - Avid CNC 2017
Public TouchPlateHeight, ProbeFeedRate, XProbeDistance, YProbeDistance, ZProbeDistance, TouchPlateWidth, XProbeDirection, YProbeDirection, ZTravelHeight, ZLiftHeight, ToolDiameter As Double 
Public ProbeX, ProbeY, PauseProbe, Abort, isImperial, isImperialUOM As Boolean

Sub Main

    NoPrompt = False            ' False = Use UI to Prompt User for corner finding options
    PauseProbe = True           ' True = Prompt user to rotate tool before X and Y axis probing
    WCSOrigin = 0               ' Default Corner 0=Left/Front 1=Left/Rear 2=Right/Front 3=Right/Rear

    ProbeX = False              ' By default, do not probe/zero X (change this to True to change the default)
    ProbeY = False              ' By default, do not probe/zero Y (change this to True to change the default)

    ProbeFeedrate = 10          'IPM, Anything from 5-12 IPM will likely work well

    TouchPlateHeight = 1            'CRP Touchplate is 1" nominal, can adjust this number to calibrate (usually not required)
    TouchPlateWidth = 2.205         'Width of Touchplate is 2.205" (56mm) wide
    XProbeDistance = 2          'How long to probe X Axis (inches)
    YProbeDistance = 2          'How long to probe Y Axis (inches)
    ZProbeDistance = 2          'How long to probe Z Axis (inches)
    ZTravelHeight = TouchPlateHeight +.125  'How high to lift tool while probing X and Y (inches)
    ZLiftHeight = TouchPlateHeight + .5     'How high to lift tool after script is complete (inches)    


    ToolDiameter = GetOEMDro(105)   
    isImperial = GetOEMLED(801)
    isImperialUOM = isImperial
    Abort = True

    If (GetOEMLED(800)) Then
        Message ("Error: Emergency Mode is Active ")
        Exit Function
    End If

    If isImperial = False Then   
        ProbeFeedrate = ProbeFeedrate * 25.4
        XProbeDistance = XProbeDistance * 25.4
        YProbeDistance = YProbeDistance * 25.4
        ZProbeDistance = ZProbeDistance * 25.4
        ZTravelHeight = ZTravelHeight * 25.4
        ZLiftHeight = ZLiftHeight * 25.4
        TouchPlateWidth = TouchPlateWidth * 25.4
        TouchPlateHeight = TouchPlateHeight * 25.4
    End If


    If NoPrompt = False Then
        Begin Dialog DlgCheckAxis 15,32,215,90,"Select Axes to Auto Zero",.DlgCheckAxis
        OKButton 140,8,40,14
        CancelButton 140,30,40,14
        GroupBox 10,3,45,50,"",.GroupAxesChk
        CheckBox 12,10,30,8,"Z Axis",.ChkBoxZAxis
        CheckBox 12,26,30,8,"X Axis",.ChkBoxXAxis
        CheckBox 125,50,80,8,"Pause Between Axes",.ChkBoxPauseProbe
        CheckBox 12,42,30,8,"Y Axis",.ChkBoxYAxis
        GroupBox 62,3,55,68,"",.GroupAxesChk

        OptionGroup .grp1
        OptionButton 65,10,50,8,"Left/Front",.ComboLeftFront
        OptionButton 65,26,50,8,"Left/Rear",.ComboLeftRear
        OptionButton 65,42,50,8,"Right/Front",.ComboRightFront
        OptionButton 65,58,50,8,"Right/Rear",.ComboRightRear

        Text 16,75,100,100,"Tool Diameter: ",.TextToolDiaLabel
        TextBox 69,75,30,10,.TextToolDiameter

        OptionGroup .grp2
        OptionButton 104,75,35,10,"inches",.UnitImperial
        OptionButton 139,75,35,10,"mm",.UnitMetric

        End Dialog

        Dim Dlg1 As DlgCheckAxis

        Dlg1.TextToolDiameter = ""+ToolDiameter
        Dlg1.grp1 = WCSOrigin 'default is left/front
        Dlg1.grp2 = 0 'default is inches (Imperial)
        If isImperial = False Then
            Dlg1.grp2 = 1
        End If
        Dlg1.ChkBoxXAxis = ProbeX
        Dlg1.ChkBoxYAxis = ProbeY
        Dlg1.ChkBoxPauseProbe = PauseProbe
        Button = Dialog ( Dlg1 )
        ProbeX = Dlg1.ChkBoxXAxis
        ProbeY = Dlg1.ChkBoxYAxis
    Else
        Select Case WCSOrigin
            Case 0
                XProbeDirection = 1
                YProbeDirection = 1
            Case 1 
                XProbeDirection = 1
                YProbeDirection = -1
            Case 2
                XProbeDirection = -1
                YProbeDirection = -1
            Case 3
                XProbeDirection = -1
                YProbeDirection = 1
        End Select
        Abort = false
    End If 

    If ( ProbeX Or ProbeY ) Then
        If Not NoPrompt Then
            If IsNumeric(Dlg1.TextToolDiameter) Then
                ToolDiameter = CDbl(Dlg1.TextToolDiameter)
                If (isImperial And Dlg1.grp2 = 1) Then
                    ToolDiameter = ToolDiameter/25.4
                End If
                If (Not isImperial And Dlg1.grp2 = 0) Then
                    ToolDiameter = ToolDiameter*25.4
                End If
            Else
                Code "(Invalid Tool Diameter)"
                Abort = true
            End If
        End If

        ToolDiameterImperial = ToolDiameter
        If Not isImperial Then
            ToolDiameterImperial = ToolDiameter/25.4
        End If
        If (Not Abort And ToolDiameterImperial <= 0) Then
            Code "(Tool Diameter is too small)"
            Abort = true
        End If
        If (Not Abort And ToolDiameterImperial > 2) Then
            Code "(Tool Diameter is too large)"
            Abort = true
        End If

        If (Not Abort And Not NoPrompt) Then
            SetOEMDro(105,ToolDiameter)
        End If
    End If

    If Not Abort Then
        Message ("Auto Tool Sequence Activating...")
        AutoZeroMachine
    End If
End Sub

Sub AutoZeroMachine()
    If GetOEMLED(825) <> 0 Then 'Check to see if the touch plate is already activated
    Code "(Touch plate is already activated, check connection and try again)"
    Else
    FeedCurrent = GetOemDRO(818) 'Get the current settings
    XCurrent = GetDro(0)
    YCurrent = GetDro(1)
    ZCurrent = GetDro(2)

    ToolRad = ToolDiameter/2

    Code "G4 P1" 'Pause 1sec
    Code "F" &ProbeFeedRate 

    'Always probe z
    ZNew = ZCurrent - ZProbeDistance
    Code "G31 Z" &ZNew
    While IsMoving()
    Wend
    SetDro(2,TouchPlateHeight)
    Code "G0 Z" &ZTravelHeight  'rapid move back off plate enough to travel

    If ProbeX Then      
        If PauseProbe Then
            MsgBox "Align Tool Flutes for X-Axis Travel and Press OK"
        End If  
        XNew = XCurrent + (XProbeDistance * XProbeDirection) 'probe vector
        Code "G31 X" &XNew
        While IsMoving() 'wait for the move to finish
        Wend
        SetDro(0,(TouchPlateWidth-ToolRad)*XProbeDirection)

        If XProbeDirection = 1 Then
            Code "G0 X" &(TouchPlateWidth/2)-ToolRad 'Center the tool on touch plate
        Else
            Code "G0 X" &((TouchPlateWidth/2)-ToolRad)*-1 'Center the tool on touch plate
        End If
    End If

    If ProbeY Then
        If PauseProbe Then
            MsgBox "Align Tool Flutes for Y-Axis Travel and Press OK"
        End If  
        YNew = YCurrent + (YProbeDistance * YProbeDirection) 'probe vector
        Code "G31 Y" &YNew
        While IsMoving() 'wait for the move to finish
        Wend
        SetDro(1,(TouchPlateWidth-ToolRad)*YProbeDirection)

        If YProbeDirection = 1 Then
            Code "G0 Y" &(TouchPlateWidth/2)-ToolRad 'Center the tool on touch plate
        Else
            Code "G0 Y" &((TouchPlateWidth/2)-ToolRad)*-1 'Center the tool on touch plate
        End If  
    End If

    Code "G0 Z" &ZLiftHeight
    Code "F" &FeedCurrent 'restore starting feed rate
    Message ("Auto Tool Sequence Complete.")

    End If 
End Sub

Function DlgCheckAxis( ControlID$, Action%, SuppValue%)
    DlgValue "ChkBoxZAxis", 1
    DlgEnable "ChkBoxZAxis",0

    If DlgValue("ChkBoxPauseProbe") = 1  Then   
        PauseProbe = True
    Else
        PauseProbe = False

    End If 

    If DlgValue("ChkBoxYAxis") = 1 Or DlgValue("ChkBoxXAxis") = 1 Then
        DlgEnable "ComboLeftFront",1
        DlgEnable "ComboLeftRear",1
        DlgEnable "ComboRightFront",1
        DlgEnable "ComboRightRear",1
        DlgEnable "ChkBoxPauseProbe",1
        DlgEnable "TextToolDiameter",1
        DlgEnable "TextToolDiaLabel",1
        DlgEnable "UnitImperial",1
        DlgEnable "UnitMetric",1
    Else 
        DlgEnable "ComboLeftFront",0
        DlgEnable "ComboLeftRear",0
        DlgEnable "ComboRightFront",0
        DlgEnable "ComboRightRear",0
        DlgEnable "ChkBoxPauseProbe",0
        DlgEnable "TextToolDiameter",0
        DlgEnable "TextToolDiaLabel",0
        DlgEnable "UnitImperial",0
        DlgEnable "UnitMetric",0
    End If      

    If DlgValue("ChkBoxXAxis") = 1  Then
        ProbeX = True
    Else
        ProbeX = False
    End If

    If DlgValue("ChkBoxYAxis") = 1  Then
        ProbeY = True
    Else
        ProbeY = False
    End If

    If Action = 3 And ControlID$ = "TextToolDiameter" And Not IsNumeric(DlgText("TextToolDiameter")) Then
        DlgText "TextToolDiameter",""+ToolDiameter
    End If

    If Action = 2 Then
        If ControlID$ = "UnitMetric" And isImperialUOM Then
            ToolDiameter = CDbl(DlgText("TextToolDiameter"))*25.4
            DlgText "TextToolDiameter",""+ToolDiameter
            isImperialUOM = false
        End If
        If ControlID$ = "UnitImperial" And Not isImperialUOM Then
            ToolDiameter = CDbl(DlgText("TextToolDiameter"))/25.4
            DlgText "TextToolDiameter",""+ToolDiameter
            isImperialUOM = true
        End If
        If ControlID$ = "Ok" Then
            Abort = False
            If DlgValue ("ComboLeftFront") = 1 Then
                XProbeDirection = 1
                YProbeDirection = 1 
            ElseIf DlgValue ("ComboLeftRear") = 1 Then
                XProbeDirection = 1
                YProbeDirection = -1 
            ElseIf DlgValue ("ComboRightRear") = 1 Then
                XProbeDirection = -1
                YProbeDirection = -1
            ElseIf DlgValue ("ComboRightFront") = 1 Then
                XProbeDirection = -1
                YProbeDirection = 1
            End If
        End If
    End If
End Function

If your CNC control computer is not connected to the internet, you can also download this script to transfer it manually. Once the script is on your control PC, simply open with Notepad and then copy/paste into the editor.

Save the file, exit the editor, and then restart Mach3.
If your machine has an aluminum table top, make sure there is something non-conductive between the z touch assembly and the table top to avoid creating a false signal. Before running the routine for the first time, make sure the emergency stop is accessible in case something is set up incorrectly to avoid over-driving your z axis.