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Work coordinates
« on: October 31, 2017, 04:32:01 AM »
Gday,
After setting up my limits and all working fine.
I setup G59 as per coordinates but when I tried to send the machine to these coordinates the X & Y worked perfect but the Z didn't move.
If I had any hair it would be in jeopardy.
Any assistance would be much appreciated.

cheers

Trevor
Re: Work coordinates
« Reply #1 on: October 31, 2017, 04:39:22 AM »
Hi Trevor,
you say that you've set up your limit switches and they are working. What about home switches? How do you reference your machine?

Soft limits, work co-ordinates are just so much hot air UNTIL the machine is referenced.

What sort of controller are you using?....parallel port or USB external controller?

Craig
My wife left with my best friend...
     and I miss him!
Re: Work coordinates
« Reply #2 on: October 31, 2017, 05:02:56 AM »
Gday Craig,
The limits I referred to are the Home Limits (proxies).
To reference the machine I hit the ref all button.
The machine then goes to the 0,0,0 which I presume is correct.
Its only when I go to the work coordinates that the problem rears its head

cheers

Trevor
Re: Work coordinates
« Reply #3 on: October 31, 2017, 05:22:27 AM »
Hi,
so are they limit switches (at the ends of the axes) or home switches or do they do double duty and do both?

When you hit <ref all> does the machine drive to some location?

What sort of controller are you using? There is a reason I'm asking...its because I want to know if its going to be feasible to get you to fit three dedicated
home switches each with its own input. This may strike you as over the top...its not. It reduces confusion and because you use decent microswitches
way more accurate and repeatable.

When you say that all axis DROs are reading zero now go to the diagnostics page. Each axis has a current position which is calculated from the machine
position and the prevailing work co-ord for that axis. Note you cannot change the machine co-ordinates EXCEPT by shifting the axes by jogging, MDIing
or running Gcode OR referencing (homing). Mach is quite happy and extremely good at maintaining a true and correct set of machine coordinates BUT it
needs to know where to start to keep its record, hence the home switches. It common to have the switches at or near the end of each axis but it doesn't have to be.
My home switches are set up to trigger about 10mm short of the end of the axis (where the limit switches are). The important point is that everytime you turn
Mach on that you reference to the exact same place, or as near exact as you can then softlimits make sense and so do work co-ordinates saved from a previous
session.

Craig
My wife left with my best friend...
     and I miss him!
Re: Work coordinates
« Reply #4 on: October 31, 2017, 05:54:04 AM »
Gday Craig,
The proxies are home switches.
I home the machine by hitting Ref All.
I then use my handheld controller to jog to a work and setup the XYZ coordinates.
Then to the Offset screen and Click the XYZ buttons on the Machine Coordinates which transfer them over to the works coordinates and them I save.
I then go back to the first screen and hit the ref all to zero the machine and hit Go to Zero to check my works coordinates are working.
Previously the X&Y worked but the Z did not.
Just been down and checked it again and all seems to be working.
Bloody Gremlins.

cheers

Trevor
Re: Work coordinates
« Reply #5 on: October 31, 2017, 01:21:01 PM »
Hi,

Quote
I home the machine by hitting Ref All.
Does the machine drive to its Home location?

Quote
I then use my handheld controller to jog to a work and setup the XYZ coordinates.
So you manually jog to the desired location.
Do you hit <zero X>, <zero Y>, <zero Z>? If you do it forces the work offsets to be such that the current position co-ords are zero, ergo the offsets
will be equal and opposite the machine co-ords. You don't need to transfer anything.

The machine co-ords are important to your machine and Mach will track them but you don't need to see them. You reference once. Manually jog to where
you want to  call 0,0,0 in your work cords for this session and hit <zero x>,<zero y>,<zero z>. You can now run your program. Each and every time you
hit the <zero> buttons the local 0,0,0 changes, so if you put a new piece in your vice jog to the corner, touch the tool on the surface, hit <zero> buttons
and the machine is ready to run the code.

Do you have separate limit switches? How are they wired?
What type of controller are you using?

Craig
My wife left with my best friend...
     and I miss him!
Re: Work coordinates
« Reply #6 on: October 31, 2017, 08:58:31 PM »
Craig,
Yes I have seperate proxies and I am running Mach 3 on a converted Chinese machine.

Trevor
Re: Work coordinates
« Reply #7 on: October 31, 2017, 10:02:54 PM »
Hi,
so does the machine drive of its own accord to the home location?

When the Ref All is complete and the machine co-ordinates are zeroed does the border of the <zero (axis)> go green?

Craig
My wife left with my best friend...
     and I miss him!
Re: Work coordinates
« Reply #8 on: November 01, 2017, 09:54:02 PM »
Gday Craig,
Yes the borders of the zero axis goes green when I REF ALL HOME and the DRO display zero.
I thought everything was OK but its not.
I have noticed that when I travel the Z axis down from home position the DRO has a + value and I was under the impression it was suppose to have a - value.

Trevor
Re: Work coordinates
« Reply #9 on: November 01, 2017, 10:27:13 PM »
Hi,
it is common for the Z axis machine zero to be at the top of its travel. If you were observing
machine co-ords then any Z co-ordinate within the machining volume would be negative.

It is unusual to have the machine co-ords displayed in the DROs, it is the norm to have work co-ordinates
displayed where zero is the surface of the material, positive Z above the material (safe) and negative Z
means below the surface, that is machining and producing chips if all is well, or a crash if you haven't got it
right.

If you look on the diagnostics page you will see how the current position is calculated from the machine co-ords and the
current work offsets.

There is a button that causes the machine co-ords to be displayed in the DROs, hitting the button and the DROs go back
to the current position which is the 'normal' condition.

The green border around the <zero (axis)> button means that axis is referenced.

Craig
My wife left with my best friend...
     and I miss him!