CNC Shark Forum

I have a project where the runtime is 26 hours+.
I do not think the neighbours will allow me to run the machine for that long.
Is there a command I can put into the toolpath that tells the machine to go to XYZ0 and pause then, after the router has cooled down or the next day, whatever the timeslot may be, press continue or goto the spot where the machine was paused.
It is not practical to just pause the machine as the safe Z is only 1 mm above the material so one has to be pretty fast to catch it while it is at safe Z.
Thanks
Wolffie

Other than dividing the job into three (or more) toolpath sets, I can't think of any good trick to help you. I played around with adding T or M codes to a sample .TAP file, but not knowing the true syntax just got errors and files that crashed the controller.

Here's what I came up with after a little tinkering with g-codes. 2 posts as a result of the 3 attachment limit.

Hope this helps.

Example VCarve Pro project and tap files (before and after editing). Explanation in the pdf attached to the post above.

Joe,
With what you're proposing wouldn't it be just as simple to hit the pause button and just shut the router off?
I had a long cut last night, (+10hrs) and had contemplated doing this but already had several hours cutting so I just let it run. I also had concerns about the stepper motors being able to maintain their position for several hours.

Hmmmmmm...............would it be possible to pause the cut, note the position of the router and stop cutting. Then edit the g-code to remove the lines before the paused state, re-position the router to where you initially stopped and start cutting again? You could also just leave the router where you paused it. Just thinking out loud here.

Joe, thanks for this. I only get a couple of hours (2 - 3 a night) when I can do cutting, and I don't want the machine running when I'm in bed, or at work.

Does anyone know if there is any concern with leaving the stepper motors holding everything in place for several hours (12?) without moving? (wear on the motors, etc)?

Thanks,

Gordon

A number of factors in any of these kinds of cases. I'm fortunate that I can let it run for hours - no one is bothered.

The useful thing about adding a dwell where there is a tool raise is that it gives you time to 'catch it' and hit the Pause button on the control panel.

While there's nothing wrong about pausing it, and shutting down the router, and coming back - you would be leaving the router in contact with the material and that has its own pros and cons associated with it.

You can of course edit the file into chunks - and that is covered that in the reference link. The one potential challenge is that the job will start from XYZ0 - and you run some risk of accuracy. There's also other things that can occur during this period that can further increase the accuracy of the 'next' part of the job being run.

By leaving the Control Box and computer/Control Panel on, even though you raised it to the rapid move height, I think this is the course of action that would result in the least amount of 'other' errors being induced.

I'm not necessarily recommending this as a normal mode of operation - but for those that have other considerations - like noise/neighbors - of all the methods we've discussed and tried, I think this one would result in the most accurate, continuous run of the job on a Shark.

I don't think there are any issues with the stepper motors holding their position with the power on. I haven't experienced any issues and my setup is mostly powered on - whether cutting or not (not necessarily the best way to do things, but sometimes I don't care to walk out to the shop or forget). I don't think leaving them on is diminishing the life expectancy.

I'm always intrigued by these long time cut posts. I'm having a hard time imagining what could take that long to cut. 26 hours is a lot. Last night I cut a 16" x 20" table top. I ran 10 separate programs, 5 different tools, 5 3D carvings. The longest one was 1 hour and 40 minutes. Every square inch of the top was machined in about 5 hours.

I try to optimize every cut for time. Spend time reviewing the feeds and speeds and stepover percentages. I only do ball mill carving over the 3D section, using an outline vector to separate it from flat areas which I machine with end mill type bits up to 3/4 inch diameter.

Hi Bill - I'm with you on this, although I do have some projects that are in essence 100% 3D and large material area which I can do 'all at once' as I have an extended bed. Some of the honeycomb based projects I run are in the 5-7 hours with a 1/4 BN and 10% step over. I can see where a project you described can end up in the much longer hours if you choose to use a 1/16 BN. When I first started out I assumed that I would require this size for 3D. I've since learned that this isn't the norm, at least for my projects. And, where I do need a 1/16 BN or EM, I can just do that small area and not run it over the whole project. The longest single job I've run is 15.5 hours - and that was a bench backboard that was all honeycomb and bees - the whole thing was touched by the cutter. Nothing wrong with choosing a 1/16 BN - but it can quickly add up with this tool in play.

It's a great tip you mention about fencing off the 3D area from the rest of it that could be done with an end mill.

But, to give you a sense of my case where I go over 8 hours - my experiment in foam. 52" x 18" - this side had honeycomb behind the lettering. 8.5 hours with a 1/4" BN, I think 12% step (that may have been a litle small).

I'm still learning how to optimize my jobs, though when I discovered the 'flat bottom/larger area' removal method, that really cut down the milling time of my 3D models.