[kentavv]

What does the "Auto Tool Zero" button do in Mach3? I don't seem to be able to find any thing about it in the Mach3 manual.

[Barker806]

It is a button that you can add VB code too...
You can enter in code like this:
Zmove = 1.5 'amount the tool will move down to hit the probe
Zpos = GetDRO(2)
Tool = GetDRO (24)
ZOffset = .5 'enter height of probe here

OldZpos = Zpos
ZPos = Zpos - ZMove
Code "G31 Z" & ZPos & " F20.0"
While IsMoving()
Wend
Zpos = GetVar (2002)
If Zpos = OldZpos - ZMove Then
responce = MsgBox ("ERROR! The tool did not hit the probe and DRO was not set" , 4 , "Probe ERROR!" )
Else
SetDRO (2,ZOffset)
End If

Code "G00 G53 Z-.1"



This will set the Z to the right height over the part

Thanks
Brian

[Normsthename]

This will set the Z to the right height over the part

I am really interested in getting this working on my CNC setup
Quick question.....
When the Z axis comes down and the bit touches the plate (3mm Thick for instance), the Z axis then backs up a set distance, say 10mm
You can then remove the plate and wire clip and press cycle start??
Does the VB code then add some sort of tool compensation so it knows that the Z axis is 13mm above the actual material???

TIA

Andy

[ger21]

Does the VB code then add some sort of tool compensation so it knows that the Z axis is 13mm above the actual material???

TIA

Andy

It resets the DRO to the correct Z height when it hit's the plate ( SetDRO (2,ZOffset)). Then when it moves up 10mm, it's just a normal 10mm Z move.

[Normsthename]

Then when it moves up 10mm, it's just a normal 10mm Z move.

I understand that it resets the DRO, but do I need to change 'Z' origins in my CAD package to tell it that the tool is actually 13mm above the material??

Thanks

Andy

[ger21]

No, the origin (Z=0) is still the top of the workpiece. When Mach3 moves up 10mm, it knows it's 10mm above the work.

[kentavv]

Is the 13mm you refer to the height of your touch probe? If so, it would appear that you would alter the previously posted VB code and update the touch probe height.

Could someone post a reference to one of these electronic height probes? I have seen mechanical ones but not electrical ones that could be interfaced to a computer. I assume they have some mechanism for handling overshooting. The VB code looks like it probes at 20ipm and I know my setup would overshoot at that speed.

[Normsthename]

s the 13mm you refer to the height of your touch probe?

The 13mm was just a 'test' figure which equated to a 3mm thick touch plate, and then the Z axis moves up 10mm to equal 13mm in total
Hope this helps.

Could someone post a reference to one of these electronic height probes?

All it consists of is an output wire from your breakout board, which you attach one end to a steel plate, and the other end you fit a crocodile clip or similar. You then put the touch plate under the bit, and attach the clip on to bit.
When the Z axis lowers and makes electrical contact, the VB code then does the rest.
You need to assign the output to the digitiser probe....I think.........

I will have a go at getting this working tomorrow.

No, the origin (Z=0) is still the top of the workpiece. When Mach3 moves up 10mm, it knows it's 10mm above the work.

Thanks GER21 for all your input

Andy


Andy

[kentavv]

A potential problem with this approach may occur if the Mach debounce and G31 feed rate high enough that before Mach reports the contact as real the tool has over shot. The mechanical ones that I have seem allow for overshooting (basically they are a fancy dial indicator). The steel plate would not be as forgiving. When I use an electronic edge finder I change the debounce to a low value and feed very slowly (1ipm). It would be really slick to be able to feed down fast and measure the overshoot. Perhaps with an electronic dial indicator?

Here is a DIY version of the mechanical height gauge.

http://www.industrialhobbies.com/how..._gauge_pt1.htm

[Normsthename]

A potential problem with this approach may occur if the Mach debounce and G31 feed rate high enough that before Mach reports the contact as real the tool has over shot.

Other Mach users are using with no problems, I will try it and see!

Andy

[ger21]

A potential problem with this approach may occur if the Mach debounce and G31 feed rate high enough that before Mach reports the contact as real the tool has over shot.

As you mentioned, you can set the feedrate in the VB script. It doesn't have to be 20. Set it low, and just jog down close before you run the Script.

[Normsthename]

Today I made up the touch plate, and wired this into Pin 15 on my breakout board, and the other wire to a earth on the breakout board.
Finally I assigned the probe to this signal.
Everything works fine when I touch the crocodile clip to the plate, I get a probe signal showing on the diagnostics screen in Mach3
Problem is when I actually clip the crodile clip onto the router bit, I get an intermittent signal flashing on the probe signal display
I would guess the intermittent signal is flashing approx. twice every second. It is very random flashing signal.
The router is powered off at the electrical socket. As soon as I unclip the wire from the router bit, the flashing signal stops???
I thought that it could be picking up noise from the Stepper motors, so I positioned the plate very near to the stepper motors with the clip off the router bit, and no flashing??
I tried altering the debounce setting, and it made it better, but I have to have a large value (2000+) before it is usuable.
Its very odd, Anyone know why I am getting this.
I have temporally altered the VB script so I now lower the router bit manually while watching the diagnostics screen, and when the probe signal is solid, I press the auto tool zero button.
It then records the thickness of the touch plate, and then moves the Z axis back upto 15mm
This works fine, but I would like to know why I get the flashing signal.

TIA

Andy

[kentavv]

You might need better grounding, shielding, or need to add a small filter cap on the signal line. Be aware that a filter cap will delay the signal. Was the router completely switched off or was only the variable speed, if so equipped, reduced to "0?"

FWIW:

Consider the impact of using a debounce of 2000. The previous code as a I understand was setup for 20ipm. So with Mach3 in 45,000Hz mode the overshoot is

2000/45000/60*20 = .015

in 25,000 mode:

2000/25000/60*20 = .027

The value becomes linearly worse if debounce or feed is increased or if Hz is decreased.

I am cautious of this approach out of concerns of not getting an accurate depth and chipping tools. In the end it is whatever you are comfortable with.

[Normsthename]

You might need better grounding, shielding, or need to add a small filter cap on the signal line.

I did'nt use any shielded cable, but neither do any of my limit swictches or EM Stops and I have never had any problems with any of those.
If I changed to a shielded cable, do I connect the screen to the chasssis earth at the box end??

Was the router completely switched off or was only the variable speed, if so equipped, reduced to "0?"

Yes, the router was completely switched off at the mains outlet, which makes it very strange!

Consider the impact of using a debounce of 2000.

I only tried the debounce setting to see if it made the problem better or worse, the delay was much too long as you say

Andy

[riporeno]

It is a button that you can add VB code too...
You can enter in code like this:
Zmove = 1.5 'amount the tool will move down to hit the probe
Zpos = GetDRO(2)
Tool = GetDRO (24)
ZOffset = .5 'enter height of probe here

OldZpos = Zpos
ZPos = Zpos - ZMove
Code "G31 Z" & ZPos & " F20.0"
While IsMoving()
Wend
Zpos = GetVar (2002)
If Zpos = OldZpos - ZMove Then
responce = MsgBox ("ERROR! The tool did not hit the probe and DRO was not set" , 4 , "Probe ERROR!" )
Else
SetDRO (2,ZOffset)
End If

Code "G00 G53 Z-.1"



This will set the Z to the right height over the part

Thanks
Brian

Hi,
I am a new Italian consumer.
excuse me but I don't speak well the English.
I have a problem with Auto TOOL Zero because when the clicco with the mouse
it tells me: function not implemented.
This that you/he/she is written above where I have to put him/it?
How do I have to name him/it?
When use screen 4 thing do I have to write in the key Auto TOOL Zero?
thanks and excused me if I don't speak well
hi
moreno

[ger21]

From the menu, choose Operator>Edit Button Script, then click the Auto Tool Zero button. Put the code there.

Screen 4 is not used for VB script.

[Greolt]

T
Problem is when I actually clip the crodile clip onto the router bit, I get an intermittent signal flashing on the probe signal display


This works fine, but I would like to know why I get the flashing signal.

Andy did you get this sorted?

This is what I found.

I had exactly the same symptom and fixed it by putting a pullup resistor on the pin that the probe is connected to. Fixed it completely.

The pin may be "floating" until the probe makes contact and picking up stray noise. That is what mine was doing.

It now works reliably and faultlessly. I don't have shielded cable and I have debounce set a 10

Greg

[riporeno]

From the menu, choose Operator>Edit Button Script, then click the Auto Tool Zero button. Put the code there.

Screen 4 is not used for VB script.

Thanks
I have resolved the problem.
very kind
regards

moreno

[Switcher]

I am really interested in getting this working on my CNC setup
Quick question.....
When the Z axis comes down and the bit touches the plate (3mm Thick for instance), the Z axis then backs up a set distance, say 10mm
You can then remove the plate and wire clip and press cycle start??
Does the VB code then add some sort of tool compensation so it knows that the Z axis is 13mm above the actual material???

TIA

Andy

It looks like the sample code already shows the "Z-axis" offset (touch plate thickness).

Zmove = 1.5 'amount the tool will move down to hit the probe
Zpos = GetDRO(2)
Tool = GetDRO (24)
ZOffset = .5 'enter height of probe here

OldZpos = Zpos
ZPos = Zpos - ZMove
Code "G31 Z" & ZPos & " F20.0"
While IsMoving()
Wend
Zpos = GetVar (2002)
If Zpos = OldZpos - ZMove Then
responce = MsgBox ("ERROR! The tool did not hit the probe and DRO was not set" , 4 , "Probe ERROR!" )
Else
SetDRO (2,ZOffset)
End If

So in your example, I think it would look like this.

ZOffset = 3.0 'enter height of probe here

.

[Greolt]

I only tried the debounce setting to see if it made the problem better or worse, the delay was much too long as you say

It is worth mentioning in this thread for readers info that since Mach version 2.4 probe has been removed from the debounce code. Good move IMO.

Greg