[Greolt]

With the type of things I am doing on my router I find I very often need to set my Z axis zero on the top of the material.

What I have been doing to set tool zero to the top of material is to use a 123 block as a known height gauge.

Put it under the tool and jog down to it, using step jog when close, 0.01mm per step, then manualy entering 25.4mm (1") into the Z axis DRO.

There's got to be a better way! (nuts)


Well there is. And lots of people have done this already. No original ideas here.

This is what I did. With the help of some people on the Artsoft forum. Mostly Scott. Thanks Scott.:cheers:

Put a user DRO on the screen using Mach's screen utility, Screen4. Assigned it OEM code 1151

Also put a LED for Probe and one for Pause or Dwell. These I will explain later. See the screen grab below as pic.

Assigned the following macro to the "Auto Tool Zero" button.

PlateThickness = GetUserDRO(1151) 'Z-plate thickness DRO

If GetOemLed (825)=0 Then 'Check to see if the probe is already grounded or faulty
DoOEMButton (1010) 'zero the Z axis so the probe move will start from here
Code "G4 P5" ' this delay gives me time to get from computer to hold probe in place
Code "G31Z-40 F500" 'probing move, can set the feed rate here as well as how far to move
While IsMoving() 'wait while it happens
Wend
ZProbePos = GetVar(2002) 'get the axact point the probe was hit
Code "G0 Z" &ZProbePos 'go back to that point, always a very small amount of overrun
While IsMoving ()
Wend
Call SetDro (2, PlateThickness) 'set the Z axis DRO to whatever is set as plate thickness
Code "G4 P0.25" 'Pause for Dro to update.
Code "G0 Z25.4" 'put the Z retract height you want here
Code "(Z axis is now zeroed)" 'puts this message in the status bar
Else
Code "(Z-Plate is grounded, check connection and try again)" 'this goes in the status bar if aplicable
Exit Sub
End If

EDIT: This is in metric. You will have to change some numbers if you still live in the Middle Ages. .......END EDIT

Made a probe touch pad from a scrap of copper clad PCB material. See pic below.

Conected to a spare input on my BOB. Mine needed a pull up resistor.

Assigned it in "Ports and Pins" as "Probe" Set as "Active Low"

The first one I made had a clip to go onto the tool. I found it worked faultlessly without it. So I ditched it. KISS

Re, my screen changes.

The "plate Thickness" DRO should be self explanatory.

The Probe LED I made big so I could see it from the machine.

My fear was that if an electrical fault happened and Mach did not stop the probe move then my spindle would drive on relentless. Causing mayhem.

So I just touch the plate to the tool and see the LED light up, before running the macro to satisfy myself that all is good.

The Pause LED just flashes during the 5 second pause I have set to give me time to get from computer to holding the plate in place.

Now you can put these items (only the DRO if that's all you want) anywhere on the screen that suits you.

I chose the area usually used for spindle control. Because I don't use it. YET!!!

Now I will repeat, this is not my idea. Lots of people use this type of device

I hope this inspires a few more to give this a try. Very useful on my type of machine. It really is easy.

Greg