Dynomotion

Group: DynoMotion Message: 7700 From: michaelthomasn Date: 6/19/2013
Subject: G53 Selectively Modal/Non-Modal
Hi Tom,

I've had a few weird issues with my mill now and then, such as behavior that mimics a stepper system that has lost some steps.

I don't have steppers, I have DC servo's.

I think I figured out what has been happening.

I almost always have my vise on the mill, with machine X,Y 0 being the left rear corner of my fixed jaw and Z0 being the upper reaches of my z.

For tool changes, I use a G53 G0 Z0 line to send the head to machine 0.

99.9 % of the time, my machine X,Y 0 is also my work coordinate (G54) X,Y 0.

Since I have always used only G54, I actually haven't ever bothered to call it out in my G code. The other machines I have worked on use G54 by default. They also have G53 as a non-modal command. After it is called, it automatically reverts back to whatever coord offset (G54, etc) is being used for the following line......whether its specified or not. If none are specified, they use G54.

I have found that Kmotioncnc does not revert back to G54 after a G53 non-modal command. Mine will use the "G54" Z which can be seen on the screen, but will remain at G53 X and Y thereafter.

I thought that was odd. Why would it use the G54 Z, but not the G54 X and Y?

Have you noticed this?

I have since added G54 (or whatever coord offset to be in use) to my post processor following a tool change that uses G53.

I haven't yet confirmed that as a fix for me, but I think it will.

This has really confounded me the couple of times that it has been an issue.

I did a search to see if anything came up for G53, but nothing relevant.

My Kmotioncnc is not current, and at the moment I cant remember which version it is.

Mike
Group: DynoMotion Message: 7702 From: michaelthomasn Date: 6/19/2013
Subject: Re: G53 Selectively Modal/Non-Modal
Tom,

I went back to the shop to see if I could repeat this occurrence, and I could not.

I had a pattern of holes that was shifted exactly the amount that was different between machine and work home after a tool change.

It was apparently a coincidence.

I'm back to being stumped......lol.

Mike

--- In DynoMotion@yahoogroups.com, "michaelthomasn" <michaelniksch@...> wrote:
>
> Hi Tom,
>
> I've had a few weird issues with my mill now and then, such as behavior that mimics a stepper system that has lost some steps.
>
> I don't have steppers, I have DC servo's.
>
> I think I figured out what has been happening.
>
> I almost always have my vise on the mill, with machine X,Y 0 being the left rear corner of my fixed jaw and Z0 being the upper reaches of my z.
>
> For tool changes, I use a G53 G0 Z0 line to send the head to machine 0.
>
> 99.9 % of the time, my machine X,Y 0 is also my work coordinate (G54) X,Y 0.
>
> Since I have always used only G54, I actually haven't ever bothered to call it out in my G code. The other machines I have worked on use G54 by default. They also have G53 as a non-modal command. After it is called, it automatically reverts back to whatever coord offset (G54, etc) is being used for the following line......whether its specified or not. If none are specified, they use G54.
>
> I have found that Kmotioncnc does not revert back to G54 after a G53 non-modal command. Mine will use the "G54" Z which can be seen on the screen, but will remain at G53 X and Y thereafter.
>
> I thought that was odd. Why would it use the G54 Z, but not the G54 X and Y?
>
> Have you noticed this?
>
> I have since added G54 (or whatever coord offset to be in use) to my post processor following a tool change that uses G53.
>
> I haven't yet confirmed that as a fix for me, but I think it will.
>
> This has really confounded me the couple of times that it has been an issue.
>
> I did a search to see if anything came up for G53, but nothing relevant.
>
> My Kmotioncnc is not current, and at the moment I cant remember which version it is.
>
> Mike
>
Group: DynoMotion Message: 7709 From: Tom Kerekes Date: 6/19/2013
Subject: Re: G53 Selectively Modal/Non-Modal
Hi Mike,

I can't think of what would cause such a thing.  The next time it happens please run KMotion.exe check if the raw KFLOP counts are still correct or shifted (or I guess you can just look at the machine coordinates).  Do you have encoder feedbak back to KFLOP?

Also determine if the G54 Fixture Offset or the G92 offset has been changed.

Also please try our latest software.

Regards
TK 

Group: DynoMotion Message: 7712 From: michaelthomasn Date: 6/19/2013
Subject: Re: G53 Selectively Modal/Non-Modal
Hi Tom,

Yes, I have encoder feedback to Kflop.

I spilled a very large cup of coffee over this laptop a while back. I cleaned it up as best I could and got it to work again, but the usb's sometimes seem flaky and will cause Kmotion to lockup which can only be remedied by disconnecting Kflop. It seemed like that was behind me, but maybe not.

I borrowed a new computer, and put the latest software on it today.

I'll see what happens tomorrow.

I don't use G92.

Mike

--- In DynoMotion@yahoogroups.com, Tom Kerekes <tk@...> wrote:
>
> Hi Mike,
>
> I can't think of what would cause such a thing.  The next time it happens please run KMotion.exe check if the raw KFLOP counts are still correct or shifted (or I guess you can just look at the machine coordinates).  Do you have encoder feedback back to KFLOP?
>
> Also determine if the G54 Fixture Offset or the G92 offset has been changed.
>
> Also please try our latest software.
>
> Regards
> TK 
>
>
> ________________________________
> From: michaelthomasn <michaelniksch@...>
> To: DynoMotion@yahoogroups.com
> Sent: Wednesday, June 19, 2013 2:02 PM
> Subject: [DynoMotion] Re: G53 Selectively Modal/Non-Modal
>
>
>
>  
> Tom,
>
> I went back to the shop to see if I could repeat this occurrence, and I could not.
>
> I had a pattern of holes that was shifted exactly the amount that was different between machine and work home after a tool change.
>
> It was apparently a coincidence.
>
> I'm back to being stumped......lol.
>
> Mike
>
> --- In DynoMotion@yahoogroups.com, "michaelthomasn" <michaelniksch@> wrote:
> >
> > Hi Tom,
> >
> > I've had a few weird issues with my mill now and then, such as behavior that mimics a stepper system that has lost some steps.
> >
> > I don't have steppers, I have DC servo's.
> >
> > I think I figured out what has been happening.
> >
> > I almost always have my vise on the mill, with machine X,Y 0 being the left rear corner of my fixed jaw and Z0 being the upper reaches of my z.
> >
> > For tool changes, I use a G53 G0 Z0 line to send the head to machine 0.
> >
> > 99.9 % of the time, my machine X,Y 0 is also my work coordinate (G54) X,Y 0.
> >
> > Since I have always used only G54, I actually haven't ever bothered to call it out in my G code. The other machines I have worked on use G54 by default. They also have G53 as a non-modal command. After it is called, it automatically reverts back to whatever coord offset (G54, etc) is being used for the following line......whether its specified or not. If none are specified, they use G54.
> >
> > I have found that Kmotioncnc does not revert back to G54 after a G53 non-modal command. Mine will use the "G54" Z which can be seen on the screen, but will remain at G53 X and Y thereafter.
> >
> > I thought that was odd. Why would it use the G54 Z, but not the G54 X and Y?
> >
> > Have you noticed this?
> >
> > I have since added G54 (or whatever coord offset to be in use) to my post processor following a tool change that uses G53.
> >
> > I haven't yet confirmed that as a fix for me, but I think it will.
> >
> > This has really confounded me the couple of times that it has been an issue.
> >
> > I did a search to see if anything came up for G53, but nothing relevant.
> >
> > My Kmotioncnc is not current, and at the moment I cant remember which version it is.
> >
> > Mike
> >
>