Dynomotion

Group: DynoMotion Message: 6833 From: ericncn Date: 2/28/2013
Subject: ruined workpiece, and Z management
Hello,

not sure whether I've made something wrong or there's something wrong in KMotionCNC but, I've ruined a workpiece. Let me try to explain what I was trying to do, and what actually happened.

I had written a small program for milling a pattern on a flat surface at constant Z height.

After starting the job the Z was set too high, so I wanted to stop (suspend) the job, set the Z at a lower level, and continue the job from there at the new Z level.

What happened is: after resetting the Z height, as soon as I hit the run button, a nasty alarm window appeared. It made me questions on possible actions, I wanted none of these so I unchecked them all. I just wanted to go on executing the program at the new Z level I'd set.

As soon as I confirmed I wanted to continue, the mill started to sink in the workpiece (while moving on the X-Y plane) and before I could hit the emergency stop, the workpiece was ruined.

So, is this behavior of the software desirable, have I done something wrong, ... ? I'm a bit confused, but I'd expected the software to either do nothing, or in the worst case it tried to compensate for my lowering the Z, by rising the Z again to its starting level.

I'd never imagined that as a consequence of myself lowering the Z, it had lowered it even more!

EC
Group: DynoMotion Message: 6834 From: Tom Kerekes Date: 2/28/2013
Subject: Re: ruined workpiece, and Z management
Hi EC,

I tried your sequence and I don't see any issue.  It does return to the original height.

How did you "Suspend" the job?  Halt?

How did you "Reset the Z height"?

What is your GCode?

Can you duplicate the problem with an "air" run?

Regards
TK

Group: DynoMotion Message: 6844 From: ericncn Date: 3/2/2013
Subject: Re: ruined workpiece, and Z management
Hi,

I used the pause/resume button.
Sorry for saying "reset". I meant I jogged the Z axe using the buttons to adjust the Z level, after that I used the "set" button to tell the program what was the intended value of Z at that level, then I resumed the execution.

OK, I'll try to reproduce the problem with an "air" run, and post the G-code after that

Thank you
EC


--- In DynoMotion@yahoogroups.com, Tom Kerekes <tk@...> wrote:
>
> Hi EC,
>
> I tried your sequence and I don't see any issue.  It does return to the original height.
>
> How did you "Suspend" the job?  Halt?
>
> How did you "Reset the Z height"?
>
> What is your GCode?
>
> Can you duplicate the problem with an "air" run?
>
>
> Regards
> TK
>
>
>
> ________________________________
> From: ericncn <ericnc@...>
> To: DynoMotion@yahoogroups.com
> Sent: Thursday, February 28, 2013 1:42 PM
> Subject: [DynoMotion] ruined workpiece, and Z management
>
>
>  
> Hello,
>
> not sure whether I've made something wrong or there's something wrong in KMotionCNC but, I've ruined a workpiece. Let me try to explain what I was trying to do, and what actually happened.
>
> I had written a small program for milling a pattern on a flat surface at constant Z height.
>
> After starting the job the Z was set too high, so I wanted to stop (suspend) the job, set the Z at a lower level, and continue the job from there at the new Z level.
>
> What happened is: after resetting the Z height, as soon as I hit the run button, a nasty alarm window appeared. It made me questions on possible actions, I wanted none of these so I unchecked them all. I just wanted to go on executing the program at the new Z level I'd set.
>
> As soon as I confirmed I wanted to continue, the mill started to sink in the workpiece (while moving on the X-Y plane) and before I could hit the emergency stop, the workpiece was ruined.
>
> So, is this behavior of the software desirable, have I done something wrong, ... ? I'm a bit confused, but I'd expected the software to either do nothing, or in the worst case it tried to compensate for my lowering the Z, by rising the Z again to its starting level.
>
> I'd never imagined that as a consequence of myself lowering the Z, it had lowered it even more!
>
> EC
Group: DynoMotion Message: 6846 From: Tom Kerekes Date: 3/2/2013
Subject: Re: ruined workpiece, and Z management
Hi EC,

What did you "set" the Z position to?  And what was your GCode commanding Z to move to?

Regards
TK