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Author Topic: How do I set Work Coords to equal machine coords when homing?  (Read 242 times)

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Like the title states I would like my work coordinates to be equal to my machine coordinates when I home the machine.

This morning I powered up my machine, homed it and started a job. But I noticed that it went to the wrong position. Fortunately i hit e-stop before it started cutting, or it would have ruined a bit, possibly a fixture.

I homed the machine again and changed the work coordinates by typing them in the window to match the machine coordinates.

I've never had an issue like this in the past. When homing It always gets the coordinates correct, for machine and work. When powering down I always save the fixture settings, so I'm not sure if this was what was saving the homing coordinates.

I did some maintenance on my machine yesterday, and manually moved the axis so I could grease the rails etc. And that may account for why it was off. But I don't think so. I've had a few crashes in the past, and homing the machine corrected the position.

If there is a setting to automatically set the values of the work coordinates when homing, why would this have changed after several months of use? It worked yesterday, but not today. The only thing I did that I don't normally do is move the axis by hand.
Re: How do I set Work Coords to equal machine coords when homing?
« Reply #1 on: April 28, 2019, 03:04:06 PM »
Hi,
you can write a script that would set your current work offsets to whatever you require but I'm thinking you
don't really understand what work offsets are.

Look on the Offsets Tab.

Note the buttons g54, g55, g56 etc. It is common that when you start Mach the default offset g54 is in operation.
If you have an alternative offset that suits a particular job or a particular material placement you could have
that offset stored in one of the other offsets, g55 for instance.

Note that if you hit the <Fixture Offset> button  then a table comes up as shown and you can view the over one hundred
sets of offsets. You can edit each one manually if desired.

In any given offset, g54 for example, if you hit the <Zero X> it causes the x axis offset to change, thus it is common for an
offset to change over the course of a Mach session. One of the most common changes is when you mount a piece of
material in the vice then jog to the start point, if you hit <Zero X>, <Zero Y>, <Zero Z> in succession the current
offset set in operation will now reflect the machine coordinate point of that location. Provided you do not alter one or
more of those entries Mach will retain that location for months/years.

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

Offline reuelt

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Re: How do I set Work Coords to equal machine coords when homing?
« Reply #2 on: April 28, 2019, 03:32:09 PM »
Like the title states I would like my work coordinates to be equal to my machine coordinates when I home the machine.

Put the following in the beginning of your G Code file assuming [REF. ALL ZERO] homing sets Machine cordinates to X0 Y0 Z0.

G28
G90 G10 L2 P1 X0 Y0 Z0

explaination
G28 sends tool to machine zero already DONE [ref all zero] before
G90 make sure G10 is in absolute units
G10 L2 P1 sets values in WORK COORDINATE #1 (nominally G54)
you already know what X0 Y0 and Z0 means

« Last Edit: April 28, 2019, 03:46:24 PM by reuelt »
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Offline reuelt

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Re: How do I set Work Coords to equal machine coords when homing?
« Reply #3 on: April 28, 2019, 04:07:19 PM »
 If you use a G10, you will need to close it out with a G11 in Mach4 (although it was not required in Mach3). 
"the gift of God is eternal life through Jesus Christ our Lord"
Re: How do I set Work Coords to equal machine coords when homing?
« Reply #4 on: April 29, 2019, 02:58:37 AM »
Hi,
sorry, forgot to attach the pic that goes with my previous post.

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

Offline smurph

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Re: How do I set Work Coords to equal machine coords when homing?
« Reply #5 on: April 30, 2019, 10:29:31 PM »
G10 only needs G11 if it is a multi-line or modal G10 operation.  Most G10 calls are on shots. 

Steve