Author Topic: Work Offset issues  (Read 6691 times)

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Offline BCMaint

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Work Offset issues
« on: August 22, 2013, 02:18:01 PM »
We have Mach3 set up on a Bridgeport V2XT with Vital System DSPMC Controller.  The problem we are having is with G54 work offsets.  We set it up just like in the video, moved over in X and Y then down in the Z.  Zero'd everything out and they are showing in the work offset screen.  The problem is when we tell the machine to "goto zero" it moves up in the z, back to 0 in X and Y, but then drops down in the Z to the offset 0.  We have use machine coords checked in the "safe z" configuration.  We have several CNC machines, this is our first to use Mach 3.  On all our other machines the Z offset doesn't come into play when sending the machine to zero, it always goes to machine 0.  We tried every way possible to get the machine to work and so far nothing is working.  I don't see any settings in the DSPMC configuration that could affect this. It's only the Z axis, X and Y work fine.

Offline TOTALLYRC

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Re: Work Offset issues
« Reply #1 on: August 22, 2013, 03:27:46 PM »
To send the machine to its home coordinates I use  G28. I even put a button on the main screen to do this.
I assume that you have home switches wired up and functioning.

Mike
We never have the time or money to do it right the first time, but we somehow manage to do it twice and then spend the money to get it right.

Offline BCMaint

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Re: Work Offset issues
« Reply #2 on: August 22, 2013, 04:05:04 PM »
Yeah, it homes out just fine.  We're not trying to send it to the machine home, we want it to go to the work offset zero position, but stay at machine zero in the Z.  So far it just moves up to machine zero in Z, moves to work offset zero in X and Y, then drops down to work zero in the Z.

Offline ger21

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Re: Work Offset issues
« Reply #3 on: August 22, 2013, 05:13:32 PM »
That's the way Goto Zero works.

If you want it to work the way you want, you'll need to write some VB code to do it.
Gerry

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Offline mrprecise44

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Re: Work Offset issues
« Reply #4 on: August 28, 2013, 01:23:49 AM »
Hello BCMaint:

Do you have home switches installed ?

It sounds like you are not using home switches to set the "machine reference zero" positions on the machine.
There are two sets of axis data. One is the "machine coordinates", and the other is the "work" coordinates. The work coordinates are the G54 .... etc.

Example: X axis has a "reference switch" when the machine spindle is at the far right end of the table travel, but just short of the limit switch. When this switch is tripped during "Ref X", the dspmc will set the "machine X Zero coordinate to 0.000., and move off the switch the amount set in the "ports and pins"  limits section.

This table has columns for all the axis, homeing in the + or - dir, active high or low, reference rate, distance to move off switch, etc.

The dspmc "Config Plugin" has a box to check on the right side of each axis page, for the Index channel on the encoder.

After all the axis are referenced, you can set the G54 home for x,y,z anywhere on the machine you choose; then when you "Goto Zero", the machine will move to the G54 Zero positions for x,y,and z which are relative to the "Machine Home x,y,z.

The dspmc controller has inputs for the reference switches.

Hope this helps.

John