Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: johnnydoughey on July 06, 2009, 08:36:27 PM

Title: Stopping and resuming
Post by: johnnydoughey on July 06, 2009, 08:36:27 PM
I am doing a larger job than expected, and have had to stop the work after 2 hours.  I hope I didn't make a mistake, but I had the router return to 0,0,0 after writing down the line it was on.  On my machine, the router does not come on until the Mach3 program begins. 

My question is... if I input the line number on the screen, and push "run from here, will the router come on and start back where it left off?
My hunch is that it will, but I would hate to ruin this piece of work.  My other option is to just rerun the entire piece from the beginning.

Thanks much for your help...
Title: Re: Stopping and resuming
Post by: HimyKabibble on July 06, 2009, 09:51:06 PM
My experience with "RunFromHere" has been less than satisfactory.  Sometimes it works fine, other times not so much.  But, I do often use "SetNextLine" to resume an interrupted program.   The only risk is if there are modal commands within the code that is skipped, then the machine will not be properly configured when you restart.  The way my post generates code, all the "Setup" and model commands are up front, so I just single-step through those, then skip ahead to where I want to re-start.  Be sure you understand where you're starting, and what it will do first.  I typically start at the "clean-up" at the end of a contour, which retracts Z and moves to a specific location, like X0Y0, to make sure the G0/G1 state is established, and the first move will ensure the machine is where the code wants it to be at that point.

Ray L.
Title: Re: Stopping and resuming
Post by: BJenkins on July 16, 2009, 05:44:33 PM
I also have issues with the Run From Here option. I would like to try the Set Next Line option but I don't understand how you "single step" through the first part of the program to insure that the spindle turns on and etc.

If someone finds time, I would appreciate learning the step by step method.

I find that when I attempt a Run From Here command, that my Z always moves to the Max Z positive limit and causes a reset.
I have my safe Z setting selected to .2

Bill J.
Title: Re: Stopping and resuming
Post by: ostie01 on July 16, 2009, 06:09:31 PM
Sometime, I like to use the single block option and hit also the TO GO button so I know exactly the distance of the next displacement of the tool or table.

Single block and TO GO are very useful option but often left alone by many users..

Title: Re: Stopping and resuming
Post by: Coastcutting on July 16, 2009, 07:50:27 PM
I have used the 'Run from Here' option many times, usually with success.

Scroll through the code to where you want to start or enter the line number, hit 'Run from Here' and wait until the G-code window has stopped at the correct point.  Then click on 'Cycle Start' and a Preperation Positioning dialogue box will pop up - check the 'spindle start' option and MAKE SURE that the Safe Z is set above the work and hit the Cycle Start again. The gantry should move to the correct position.  Hit Cycle Start again and the program should then continue cutting as per normal. 

Provided that you do not reset the 0,0,0 it should be OK. 

You will manually have to turn on the Dust/Vacuum or anything else that needs to be operational when cutting.

Title: Re: Stopping and resuming
Post by: vmax549 on July 17, 2009, 10:35:04 AM
How accurately it will resume work is up to the machine. With motors there can always be the relaxing when the power shuts off. If the gantry is in any twist then when the power shuts off it relaxes as well.

THat said the best way to restart a long job is to find a spot in the code that is close to where ou what to restart. Make sure that that spot is not into the material. Look for a line that the Z has retracted back up above the work. (or add a line to ensure it is) then select the next line and do a run from here. WHen yoou start make sure the tool is above the work so it has nothing to crash into on the way to the restart position.

THen IF you are still in the same position as you started work will resume just as you left it.

Another option I use if I know I will stop mid program is to program and cut a feature in the scrap portion of the material such as a hole. THen I write down the true position of the center of the hole. When I come back I probe the center of the circle and then reset the machine to the same value that I wrote down.

Another way is to find 2 spots in the program that the part is cut in x and y that run parralel for a short distance then go and touch off on those spot and reset mach to the correct positions in xy.

OR you can always reref home the machine IF your home switches are accurate.

One thing you must always remember is the RUN FROM HERE restarts from the line PRECEEDING the line you picked. SO IF it is in the bottom of a pocket that is where the machine will TRY to go to first. Just make sure there is a clear PATH to get there.

Hope that helps, I use RFH every day and 99% of the time there are no surprises once you learn the quirks to it.

(;-) TP
Title: Re: Stopping and resuming
Post by: BJenkins on July 17, 2009, 02:40:47 PM
Yes this does help (Thanks!) but I need to go over a couple of points just to make sure.

First, I do pick a line in the code that is out of the part. The problem is, after going through the Run From Here steps, and select Cycle start to re start the job, my Z goes all the way up to the positive Z limit and crashes and then requires a reset. I have my safe Z set to .2 and the line in the code I pick is also .2 out of the part. I can only guess that there is a setting that I have missed or that I am not following the procedure correctly.

You mentioned that Run From Here starts at the line before the line that has actually been selected. Does this mean then, if I want to start on line 19, that I really need to set line 20?

Thanks for the help.
Bill J.
Title: Re: Stopping and resuming
Post by: Hood on July 17, 2009, 04:11:52 PM
What are you using for safe Z? is it machine work or incremental?

Yes thats correct for the line.
Title: Re: Stopping and resuming
Post by: BJenkins on July 17, 2009, 04:44:40 PM
Hi Hood,

Thanks for helping again. I have my safe Z set to machine coordinates.

Title: Re: Stopping and resuming
Post by: Hood on July 17, 2009, 04:47:10 PM
certainly shouldnt crash the Z then, could you have lost steps on the Z?
Title: Re: Stopping and resuming
Post by: BJenkins on July 17, 2009, 04:56:49 PM
I will do some experimenting but I don't think I lost steps.

I will also confirm that machine coordinates are set as I said. I'm on the home computer so I will need to confirm that the setting is set to machine coordinates but I am pretty sure that this is the case.

I will report back after I have a chance to check this.

Title: Re: Stopping and resuming
Post by: vmax549 on July 17, 2009, 05:04:25 PM
check and see if your machine cords are where you think they are. Set mach to mach coords then creep up to the limit switch and check the values

(;-) TP
Title: Re: Stopping and resuming
Post by: BJenkins on July 24, 2009, 06:00:57 AM
I found that my Safe Z Setting was set to Machine Coordinates. I experimented and changed it to Work Coordinates and Z now moves to +.2 above the work as I want. I guess since I don't use a Home Switch set up (at least not yet) that I don't use Machine Coordinates. I'm a NewBee.
I experimented with the Run From Here command again and it did work although at this point, I will keep my hand on the emergency shutoff when I try this due to lack of confidence. It's a little scary. Ha!

Now I have a question regarding Backlash settings that I will post in a new thread.