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  #1  
Old Mon 04 February 2008, 21:18
Marc Shlaes
Just call me: Marc
 
Cleveland, OH
United States of America
Send a message via Skype™ to Marc Shlaes
Z-zero plate - for calibrating z-height to workpiece or table

Gerald, Greolt,

I have been wanting to ask this for a very long time. If the answer is here and I missed it or if it is very obvious, I apologize.

Could you quickly explain how a zero touch plate works? Do you attach some kind of lead to the router and pass current through the bit that sends a signal through the touch plate when the bit and touch plate meet. Or... is there current in the touchplate that goes to ground when the bit touches it? Or, and more likely, is it neither of these pure guesses?

I have wondered about this for months but I figured somewhere along the line, the answer would become obvious... but it hasn't. Thanks tons!
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  #2  
Old Mon 04 February 2008, 22:48
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
Marc, typically there are two wires, one with a crocodile clip, other with an alu plate. Clip goes to cutting bit to ground it properly, plate carries 5V. When bit touches plate it drops (shorts) the plate voltage to 0v. PMDX senses it as an input.

Some people work happily without the ground wire and clip because the cutter grounds electrically via the router bearings. Folk with spindles and ceramic bearings discovered that this does not ground and the spindle just keeps driving on into the table, lifting the y-car. (Imagine if the y-car could not lift . . . )

Then there are coated bits TiN or diamond/ceramic which also do not conduct . . . .
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  #3  
Old Mon 04 February 2008, 22:55
Marc Shlaes
Just call me: Marc
 
Cleveland, OH
United States of America
Send a message via Skype™ to Marc Shlaes
Gerald,

Thanks tons. It is nice to know that my guesses weren't that far off the mark.

One thing I really love about this forum is the subtle exposure to the rest of the world. Here in the US (probably because we have them), we call it an alligator clip.
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  #4  
Old Mon 04 February 2008, 23:55
Greolt
Just call me: Greg
 
Victoria
Australia
Marc I am not familiar with the PMDX boards so I have had a read of the PDF manual for the 122.

The 122 has pullups on the inputs. This is good.

Most of the board manufacturers like to build in pulldowns. Fine for limit switches, bad for the simple Auto Tool Zero device.

What the device needs, to keep it as simple as it is, is an input that is "High" when at rest.

That means it can be made "Active" by grounding, or touching the tool.

The rest is as Gerald has said.

I use no Crocodile clip.

Greg
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  #5  
Old Mon 18 February 2008, 16:47
cncb
Just call me: Brian
 
Connecticut
United States of America
Thanks for the info, Greg and Gerald. Been following Greg's routine for awhile.. I may have viewed his youtube video 20 times as well in the past too. In particular since most mechmaters are using the PMDX-122, which input are you finding yourselves using on the BOB for this function?
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  #6  
Old Wed 20 February 2008, 10:02
rkd
Just call me: Ryan
 
BC
Canada
Greg, I have a question for you if you don't mind, I'll wait my turn though. I am using the z-zero script you posted on cnczone. My question is, how would I utilize a remote pushbutton to activate the script? I use remote pushbuttons for pause and resume functions, but I can't find documentation onn how to use a remote pushbutton to activate a user created script.
Thank you, Ryan
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  #7  
Old Wed 20 February 2008, 11:57
smreish
Just call me: Sean - #5, 28, 58 and others
 
Orlando, Florida
United States of America
push button tutorial

Ryan,

HOW to set up a switch or pushbutton in Mach3 for the MechMate.

Follow this tutorial
Gerald walked me thru this earlier in the week.
OEM codes for reference to the tutorial
Sean

Last edited by smreish; Wed 20 February 2008 at 12:00..
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  #8  
Old Wed 20 February 2008, 12:11
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
Sean, that doesn't answer Ryan's question - I am also keen to hear how Greg replies to him. The difference here is; how does one use a hardwired button to start a script?...ie. to find a bit of program and execute it.
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  #9  
Old Wed 20 February 2008, 12:25
Greg J
Just call me: Greg #13
 
Hagerman, New Mexico
United States of America
Doesn't this thread (Artsoft website) answer Ryan's question. I'm not at that stage YET.


http://www.machsupport.com/forum/ind...6&topic=2136.0
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  #10  
Old Wed 20 February 2008, 13:50
rkd
Just call me: Ryan
 
BC
Canada
I can get the script to work fine with the on screen button. I can also get the pause and resume functions to work well using the OEM codes as Gerald has decribed somewhere on this forum.
What I am having trouble with is how to assign a remote pushbutton to an on-screen button that does not have an OEM code assigned to it ie. custom script.
I asked this question on the Mach forum a while ago and I got this answer.

I think you need to set an oem trigger up, In ports and pin's, Inputs, To a OEM trigger # (1-15) for your switch.

Then include that triggers oem code in your script, something sorta like this.

If IsInputActive( OEM Trig # ) Then
DeActivateSignal( OEM code )
Else
ActivateSignal( OEM code )
End If

Well it's a Start, Chip


It's a little beyond my understanding of scripts and such, so hopefully someone smarter than myself will be able to help.
Thanks, Ryan
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  #11  
Old Wed 20 February 2008, 13:59
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
Everyone's noticed that I have 4 pushbuttons on the y-car. 3 of them are defined (E-Stop, resume, pause) and number 4 is intended for exactly this thing that Ryan is asking about.

Part of the cutter change process is to re-zero the z-height (cutter lengths vary). So I want to run the z-zero routine by pressing the button at the y-car. Save 2 walks to the keyboard and back . . . .

Finish changing cutter
Slip touch plate under cutter
Run zero routine
Remove plate
Re-start job

In fact, the keyboard can be locked away in a dustproof place, while the daily grind is done purely on the buttons on the gantry (by an unskilled operator)
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  #12  
Old Wed 20 February 2008, 14:00
Greg J
Just call me: Greg #13
 
Hagerman, New Mexico
United States of America
Ryan,

I'm just starting to get to this stage of the project. I'm getting very close to my MM cutting wood, so the next phase is understanding Mach and all it's capabilities.

Anyways, your issue may involve using Visual Basic to program the script in Mach. I'm sure this forum will come up with an answer before I do, but if I learn something, this forum will be the first to know.
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  #13  
Old Wed 20 February 2008, 15:36
Greolt
Just call me: Greg
 
Victoria
Australia
To have a hard wired button activate the tool zero script I believe this is now done with a brain. A recent Mach feature.

This is not something I have done myself so don't have details but should be easy to find out.

Using external buttons is a common requirement. When there are lots of buttons then ModIO is often used but for this if you have a spare input that should suffice.

Greg


EDIT: I will do a little research on using a brain together with an input. Get back to you.

Last edited by Greolt; Wed 20 February 2008 at 15:39..
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  #14  
Old Wed 20 February 2008, 20:36
Greolt
Just call me: Greg
 
Victoria
Australia
No I was wrong a VB script can not be run using a brain.

So the answer is in a macro pump. I have not done that either.

Doing some research now on macro pumps. Sounds like it will be relatively simple. Has to be for me to get it.

Greg
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  #15  
Old Thu 21 February 2008, 08:10
Greg J
Just call me: Greg #13
 
Hagerman, New Mexico
United States of America
Has anyone tried emailing Art or Brain at Artsoft with this question?

I'm not even close to asking an intelligent question on this subject to Artsoft. Give me a couple more months, and I will be.
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  #16  
Old Thu 21 February 2008, 08:19
sailfl
Just call me: Nils #12
 
Winter Park, FL
United States of America
Greg,

I think you macro pump also. I am starting to look at the VB programming.
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  #17  
Old Thu 28 February 2008, 04:19
Greolt
Just call me: Greg
 
Victoria
Australia
Have been doing some reading and messaging with Scott on the Artsoft site.

I now have an external switch to activate the Auto Tool Zero routine.

Testing so far has been good. It has some safety features built in.

It involves a momentary switch connected to a spare input on the BOB.

A macropump runs in Mach in the background at about four times a second and polls the input.

Checks to see if spindle is running and also if the system is in motion.

If all those conditions are met it runs the zero routine.

Greg
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  #18  
Old Thu 28 February 2008, 04:37
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
That's going to be very useful!
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  #19  
Old Thu 28 February 2008, 04:39
sailfl
Just call me: Nils #12
 
Winter Park, FL
United States of America
Greg,

Great progress and I will be interested in seeing how the code looks.
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  #20  
Old Thu 28 February 2008, 05:56
J.R. Hatcher
Just call me: J.R. #4
 
Wilmington, North Carolina
United States of America
Send a message via Skype™ to J.R. Hatcher
Everything I know about code can be read between the lines of this word .... N _ O _ T _ H _ I _ N _ G .
But I am interested in the zero plate and setting one up for my machine.
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  #21  
Old Thu 28 February 2008, 07:14
Greg J
Just call me: Greg #13
 
Hagerman, New Mexico
United States of America
Greg,

I'm very interested in your code. It's been awhile since I've written any code, so I'll have to dust the brain for cobwebs. Along with the shielded cable, I also received a couple of books on CNC programing and VB.
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  #22  
Old Thu 28 February 2008, 07:33
Greolt
Just call me: Greg
 
Victoria
Australia
OK give me a couple of days. I want to make it as bullet proof as I can. Still learning.

J.R. the zero plate is fairly simple to set up. This idea of having an external switch trigger it will make setup a bit more complex.

Greg
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  #23  
Old Thu 28 February 2008, 07:38
domino11
Just call me: Heath
 
Cornwall, Ontario
Canada
Greg,
Would you also be able to trigger it from the Multimedia remote like Sean is going to use? That might be useful, since a lot of the guys seem to be going to it for jogging etc?

Heath.
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  #24  
Old Thu 28 February 2008, 07:41
Greolt
Just call me: Greg
 
Victoria
Australia
Which remote do you mean. If it is the Shuttle Pro, then that is easy.

Greg
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  #25  
Old Thu 28 February 2008, 07:50
domino11
Just call me: Heath
 
Cornwall, Ontario
Canada
Greg,
Yes it was the Shuttle Pro I was wondering about. Couldnt remember the name this morning.

Heath
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  #26  
Old Thu 28 February 2008, 08:52
Greolt
Just call me: Greg
 
Victoria
Australia
If you look at the Shuttle Pro plugin configuration screen you will see that a button can be set to call a macro directly from the macro's folder.

So that is just about as easy as setting a button script.

I have two set on my Shuttle. One for "Auto Tool Zero" and one for "Laser Zero".

Greg
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  #27  
Old Thu 28 February 2008, 10:37
rkd
Just call me: Ryan
 
BC
Canada
This sounds very good! Can't wait to try it.
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  #28  
Old Thu 28 February 2008, 16:36
smreish
Just call me: Sean - #5, 28, 58 and others
 
Orlando, Florida
United States of America
I asked the question if JR had an additional input available for the touch plate, not for a button to activate it. I assumed (duck for cover) that JR would use the shuttlepro to initiate the zero call.....

But for all of this to work, would you not still need a contact available to "sense" the tool bit and get the PMDX to go high?
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  #29  
Old Thu 28 February 2008, 17:37
Greolt
Just call me: Greg
 
Victoria
Australia
I'm sorry I must be tired. Can't follow your question.

Greg
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  #30  
Old Thu 28 February 2008, 17:59
J.R. Hatcher
Just call me: J.R. #4
 
Wilmington, North Carolina
United States of America
Send a message via Skype™ to J.R. Hatcher
I would like to use the shuttle pro. I have some buttons available, also have a few inputs on the bob and an extra pair of wires. What I'm lacking is the know how. I'm not in a hurry, I would rather wait until the trials are finished. Thanks everyone.
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