Pause function for use with a router

I have EMC working just nicely now on a router, cutting aluminium plate at the moment but shortly moving on to cutting wood. What I cannot do is simply stop the motion ... a tungsten cutter running deep in the wood at 18,000 RPM last seconds before smoke starts to come out if you stop the motion. The scheme I am ging to describe is what my last machine used to do and the one before that ... and what happens on Multicam machines ..

Here's what I need to happen when I push a "pause" button:

<stop motion>
G28.1 (remember where we are)
G53 G0 Z0.0 (retract the Z to top of motion)
M5 (stop the spindle)

Now the machine is safely paused, it would be nice to be able to jog it around, but by no means essential.

when I unpause it, in order to restart:

G53 G0 Z0.00 (make sure Z is all the way up, just in case I had jogged it during the pause for some reason)
G53 G0 X#5161 Y#5162 (get X and Y back to where we were)
M3 (start the spindle)
G4 P4.0 (wait for speed)
G53 G1 Z#5163 (lower the tool into the job, to the place we were)
<run motion>

Any ideas on how to do this? Ideally it would be from a pause button on a pendant eventually, but that can wait.

Although I do not know all linuxcnc possibility's, I think that is not possible, at least currently.

Pausing and doing anything (like jogging) is very useful but I believe it brings a lot of problems on the linuxcnc motion control to resume the cycle after any change.

This would be a very nice addition to linuxcnc.

It's pretty much essential for use on a router ... I could live without the jog, but the retract to Z zero is essential

I read something about jog while paused being possible in 2.7 and I seem to remember Andy Pugh explaining how to do it, but too much beer has passed through the brain since then.

I am surprised you say that so many of your machines you've had do this. This has not been my experience. None of the machines we have do it, except for 3 small light duty sign making routers from Gerber (3 Komos, a Northwood, a Heian, a SCMI Routomat, and a couple of Omni Techs all don't). Normally on most machines you have to manually command a spindle stop and raise. There are situations where raising and shutting off the spindle on a router automatically could be just as bad as letting it run (such as milling with a large t-slot bit like when making slat wall).

My Vytek Rebel 2 does this, the Bulleri I just sold did this, the Multicam we have does this ... yes, there are situations where using a T slot cutter would be a problem, but I don't posses a T slot cutter, so I should be safe.

Trust me, if you stop the motion on a 12mm cutter deep in 18mm ply at 18,000 RPM, it will cause a fire very quickly.

I am currently running ally sheet at the moment, but I need to start on wood soon, and it's not uncommon to want to pause the program to clear a problem on the nested sheet (like a part that has popped up) and then continue again.

Found this: wiki.linuxcnc.org/cgi-bin/wiki.pl?Jog-While-Paused which sounds like it is part way there ... now I just have to figure out if that is built into 2.7 already ... and then try and automate the Z up ...

It usually takes about 30 sec to a minute (sometimes a little more). That is more than enough time to stop the spindle manually. I'm not familiar with your machine, but a lot of routers have the spindle mounted to an air cylinder to raise and lower it to the cutting position (often when multiple tool heads are mounted to the same z axis) If your router has this feature, I think it would be simple to add a means to raise it when you pause. Doing it with only the z axis, will be trickier, but I don't think it'll be impossible. You could possibley insert an offset hal component between the z comand then have a button that turns that on and off to raise the z to a safe height when you're pausing. It wouldn't be automatic, might be good enough.

This particular machine is a simple single head machine with a servo-driven Z axis, nothing complex. It's a retrofit after the ancient controller on it lost it's init code. EMC seemed like the best option to get the servos up and running in closed loop.

I would prefer a single-button solution as when things go wrong and you quickly need to pause the job, that's when you are going to forget the second button.

Is there a way to find out if that code linked above made it's way into 2.7? or did it work it's way into MachineKit?

mmm .. sorry, I must be kinda dumb today.

I don't really understand how to hook up that "moveoff" thing to do what I need. I guess I can skip the GUI as I don't need that, so I'm guessing I hook this "moveoff" block up in the Z axis and trigger it to retract the Z just after the pause button is hit?