'Soft' Pause and 'Hard' Feed Hold

[NewToThis (Peter)]

Would it be possible to make the feed hold option (with mechanical switches) replicate the pause option in CM, please?

Just in case an explanation is required, using a phyisical, feed hold button has (initially) the same effect as pressing Pause in CM, but you need to press the button a second time to return control back to CM, to either Resume or Stop the job.

I would like the free hold button to do what it does on the first press, and give control immediately to CM.

I don’'t think it would be a particulalry good idea to Resume from a second pressing, but I can see the benefits of it.

Thank you

[nwallace (Nick Wallace)]

I am pretty sure this is a function of GRBL and not Carbide Motion. Someone else will have to confirm this but I don’t think it is something they could change easily.

[Julien]

@nwallace

Someone else will have to confirm this

The version of GRBL compiled with the Shapeoko-specific configuration does this:

• upon detecting the feedhold signal: retract partially, stop spindle, retract fully to parking position (top of the Z)
• upon receiving a Cycle Start/Resume command (~), plunge back, restart spindle, complete plunge into the cut at the original depth

The part that CM manages is reactivating the start button in the user interface upon the second detection of the feedhold signal. GRBL does not do anything about mutiple activations of feedhold once it has been triggered once, only a Cycle Start/Resume command will allow to resume. Once the Start button is re-enabled in CM, clicking it will send a “~” behind the scenes to tell GRBL to resume.

More details than anyone wants to know in this thread:

Feedhold (the definitive thread?)

The other day @gmack asked about documenting the specifics of the Feedhold signal, and while there are already many posts on that topic, they are a bit scattered in various threads, so I figured I would try and tell the full Feedhold story here in case anyone is interested (and since I have been playing with this, so I might as well dump my notes) Let me steal a pic from another thread to illustrate where Feedhold signal pins are on a v2.4 controller: [image] the corresponding female connect…

I’m unclear then about the request:

@NewToThis

I would like the free hold button to do what it does on the first press, and give control immediately to CM.

Isn’t this what it is doing already ? on the second press it re-enables Start, which allows one to either resume (by clicking “Start”…granted, it could be called resume then), or stop the job.

[NewToThis (Peter)]

@NewToThis

I would like the free hold button to do what it does on the first press, and give control immediately to CM.

Isn’t this what it is doing already ? on the second press it re-enables Start, which allows one to either resume (by clicking “Start”…granted, it could be called resume then), or stop the job.

Erm, I’m confused, sorry @Julien

I thought I asked that the control of the system to go to CM on the first press of the feed-hold button, rather than the second, as it does when pressing the Pause button in CM.

@Julien

• upon detecting the feed hold signal: retract partially, stop spindle, retract fully to parking position (top of the Z)
• upon receiving a Cycle Start/Resume command (~), plunge back, restart spindle, complete plunge into the cut at the original depth

This is exactly as it should be - except control doesn’t move to CM until the second press of the free hold button to allow the Cycle Start/Resume/Stop ‘workflow’ to take place.

[Julien]

Got it, read that too fast, sorry!
I can’t comment on the rationale for the current implementation in CM, or whether there is any plan to change it. Use of the physical feedhold signal on the controller is a grey area that is not officially supported, so I would not hold my breath