Machsupport Forum

Mach Discussion => FAQs => Topic started by: bobwelder on November 06, 2017, 01:54:48 AM

Title: Z Axis and machine coords
Post by: bobwelder on November 06, 2017, 01:54:48 AM
I've hunted high and low for an answer to this.
I'm trying to use scripting to set up floating torch for my plasma (Hypertherm 45) Now the problem I'm having appears to be an odd one. When trying to read the position of the z axis from the machine coords it reads 0 yet the working coords are reading the correct values. The machine works brilliantly but Mach 3 seems to be ignoring the z axis coords
Please help
Many thanks in advance
Rob
Title: Re: Z Axis and machine coords
Post by: joeaverage on November 06, 2017, 05:12:32 AM
Hi,
commonly machine co-ord Z=0 is the very top of the Z axis travel.

You say the work co-ords are working OK. Then the machine co-ords must be working too, the work co-ords are just a numerically shifted copy of the machine
co-ords after all.

Can you explain a bit more about what you see and why you consider it faulty?

Craig
Title: Re: Z Axis and machine coords
Post by: bobwelder on November 06, 2017, 05:37:04 AM
The X and Y machine coords work faultlessly just dont understand why the Z doesn't do the same. If i go into diags both the user and machine coords work for the XY but not the Z. just the user coords work. If i use scripts they all seem the refer to the machine coords which of course is a problem for me, just want to know why theZ doesn't seem to work the same.
The long and the short is the floating head ineed to put on my plasma and i was just hoping to use the PROBE G31 function alas that doesn't seem to work even if i trigger the probe.
This is my reference....
http://proma-elektronika.com/index.php/en/tips/plasma-detekcja-materialu

I must be missing something as it just doesnt work.

Thanks again for your help
Title: Re: Z Axis and machine coords
Post by: joeaverage on November 06, 2017, 05:39:58 AM
Hi,
do the Z work co-ords go up and own when you jog the Z axis?

Craig
Title: Re: Z Axis and machine coords
Post by: bobwelder on November 06, 2017, 07:11:34 AM
no, not on the machine coords

Rob
Title: Re: Z Axis and machine coords
Post by: joeaverage on November 06, 2017, 08:54:03 AM
Hi,
what about the Z axis DRO? Does it go up and down as you jog the axis?

If it does then the Z axis machine co-ordinates ARE changing.

Current Position=Machine Co-ordinate - Work Offset

If the Current Position is changing with a fixed Work Offset then the Machine Co-ordinates MUST be changing as well.

Craig
Title: Re: Z Axis and machine coords
Post by: bobwelder on November 06, 2017, 08:59:30 AM
Hi Craig
I believe they aren't. If i write a script to read in the machine coords for Z i get 0
I'll have a play with some more scripts later and get you an output.

Thanks
Rob
Title: Re: Z Axis and machine coords
Post by: joeaverage on November 06, 2017, 09:14:45 AM
Hi,
does the Z axis DRO change or not?

Craig
Title: Re: Z Axis and machine coords
Post by: bobwelder on November 06, 2017, 09:23:41 AM
Hi
It changes on the Program Run screen but on the Diags screen it doesn't change on the machine coords like the XY does.
Sorry its a bit difficult to describe.
I'll grab a screen shot in a moment.

Thanks for your patience with this
Rob
Title: Re: Z Axis and machine coords
Post by: joeaverage on November 06, 2017, 09:28:54 AM
Hi,
if the Z axis DRO is changing then the Z axis machine co-ordinates must be changing also.

Craig
Title: Re: Z Axis and machine coords
Post by: bobwelder on November 06, 2017, 09:44:15 AM
Hi Craig
See attached.
Title: Re: Z Axis and machine coords
Post by: joeaverage on November 06, 2017, 09:49:17 AM
Hi,
when you jog the Z axis does it physically move?

Craig
Title: Re: Z Axis and machine coords
Post by: bobwelder on November 06, 2017, 09:52:44 AM
Hi
Yes it does. The machine works perfectly. I just want to do material detect using a floating head.
But all the sample scripts i find dont seem to fire the Probe because it appears that there is no Z to read but i know the z is fine.
Grr
Thanks
Rob
Title: Re: Z Axis and machine coords
Post by: joeaverage on November 06, 2017, 09:58:05 AM
Hi,
forget the G31 until you have this sorted.

On the diagnostic screen jog the Z axis. Does the axis physically move? Does the number Current Position change? Does the number Machine Co-ordinate change?

Craig
Title: Re: Z Axis and machine coords
Post by: joeaverage on November 06, 2017, 10:14:22 AM
Hi,
it fundamental to Mach, in fact all CNC machines if an axis moves then the machine co-ordinates change.

If your Z axis is moving and your Z axis machine co-ordinates are not changing the your copy of Mach is broken somehow.

G31 is coded in current work co-ordinates. So:

G31 Z -0.5 F10...... will cause the Z axis to drive at a rate of 10 in/min from its current location to -0.5 inch or until it detects a probe strike.

Craig
Title: Re: Z Axis and machine coords
Post by: bobwelder on November 06, 2017, 10:26:23 AM
Hi Craig
When I jog the Z axis it moves, The current position changes but the Machine Coords do not change even though they do for the XY
I've installed Mach3 on 3 computers now and I have the same problem. I'm confused.
Plain vanilla installs as well, nothing changed.
Oh and the G31 works but when I trigger the Probe it doesnt stop the Z axis.
I need to look into this further.
Thanks
Rob
Title: Re: Z Axis and machine coords
Post by: ger21 on November 06, 2017, 11:57:41 AM
What motion controller are you using?
As Craig says, if the machine is moving, the machine coordinates should be changing. If not, something is seriously wrong with your installation.
Title: Re: Z Axis and machine coords
Post by: bobwelder on November 06, 2017, 12:20:41 PM
Hi Gerry
I'm using a UC100 from cnc4you.co.uk
Its just odd that the other axis are fine.

Thanks
Rob
Title: Re: Z Axis and machine coords
Post by: joeaverage on November 06, 2017, 12:35:21 PM
Hi,
I can' conceive of a fault that would allow an axis to move WITHOUT the machine co-ords changing.

Try a fresh copy of Mach. other than that I think it must be the controller. Email CNCDrive direct.

Craig
Title: Re: Z Axis and machine coords
Post by: ger21 on November 06, 2017, 02:59:09 PM
Do you have the latest plugin for the UC100? You can update it from the plugin monitor screen in Mach3.