Starting and Stoping Middle of G Code

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Chiefmedic
Posts: 37
Joined: Sat Sep 11, 2010 8:25 pm

Starting and Stoping Middle of G Code

Post by Chiefmedic »

Hello to all my CNC Shark Friends....

I am working on a project, that the Finishing Toolpath is about 45 hours in length. Does anyone have any ideas on Starting and Stoping and then Restarting the cutting process mid-stream. I know that I can Pause the process, turn off the router, leaving the computer and controller on, but I am looking for a way to turn everything off, and start back at the Line of G code that I left off at. Due to other projects, it might be two or three days in-between cutting sessions.

Example: The length of code for "Widget" is 780241 lines long. Lets say my first session runs Line 1 through line 90323, I would like to end here and restart again for the second session, starting backup at line 90324 and so forth. I would leave the CNC Shark positioned where I ended, and then start again from there.

Does any one know if there have been other "Posts" here on this subject?

Thanks

Dave

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Buc
Posts: 548
Joined: Mon Aug 16, 2010 9:34 pm
Location: Waterford, PA

Re: Starting and Stoping Middle of G Code

Post by Buc »

I have not failed. I've just found 10,000 ways that won't work.

Thomas A. Edison

The Only Easy Day Was Yesterday

tmerrill
Posts: 61
Joined: Sun Nov 13, 2011 5:11 pm

Re: Starting and Stoping Middle of G Code

Post by tmerrill »

Hi Dave,

A 45 hour finish pass is very impressive, but have you gone through the steps to adjust the time estimates for your machine?

If not, this Vectric FAQ may help you:

http://support.vectric.com/aspire-quest ... ining-time

Tim

4DThinker
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Re: Starting and Stoping Middle of G Code

Post by 4DThinker »

I've bumped into long jobs I didn't want to (or couldn't) sit through on occasion. Found leaving the bit at 0,0,0 easy enough, but editing the G-Code is easier from your source program. VCarve lets you pick all, 1, or any of the seperate tool paths to save to a file. Last job I did I divided it up into three seperate files. Put all the pockets into one, all the textures into another, and all the profile cutouts into the third. So long as I move the bit to 0,0,0 before shutting down, I can resume with the next file any later time. Just make sure to send the bit to your current 0,0,0 or you'll have a nightmare trying to find it the next day. If you have a bit change in the middle, just make sure you start up the controller software and 0,0,0 is where you left it before doing the change as usual.

Chiefmedic
Posts: 37
Joined: Sat Sep 11, 2010 8:25 pm

Re: Starting and Stoping Middle of G Code

Post by Chiefmedic »

Hello..

Thanks for the help. I am cutting a large "Last Supper", using Cut3D. The time of 45 hrs was what the program gave me. I will look at all the articles.

Sincerely;

Dave

Chiefmedic
Posts: 37
Joined: Sat Sep 11, 2010 8:25 pm

Re: Starting and Stoping Middle of G Code

Post by Chiefmedic »

Buc, Tim and 4DThinker...

When using "Tape Splitting", at the end of each session should I return to the original 0,0,0, or leave the machine at the spot where I am ending the current session?

Dave

tmerrill
Posts: 61
Joined: Sun Nov 13, 2011 5:11 pm

Re: Starting and Stoping Middle of G Code

Post by tmerrill »

Dave,

First, it may have changed but the last I knew Cut3D did not support Tape Splitting and would give an error if you tried to use a post processor with the command inserted. If this is still the case, you may be able to import the Cut3D toolpaths into VCP and save the toopaths using a VCP post processor with the Tape Splitting commands.

Tape Splitting creates individual standalone cut files and each will have the full header and footer that your post processor normally creates. This typically means your machine will return to its Home position at the end of a cut file and wait for you to run the next cut file or secure the machine for the day.

Realize that Tape Splitting was added to support CNC machines that were memory limited or restricted to running a set number of lines of code at a time. I have tested it and used it in actual projects and while it works, it was not intended for this purpose. One issue you may very well see are lines where one cut file has stopped and the next starts. This can be caused by wood movement overnight and/or a difference in the bit's Z-zero setting if your machine doesn't hold position while shutdown or paused. Not saying it will happen, but you should realize the possibility exists. And believe me, if it happens in a detailed area of the carving you aren't going to easily sand it out.

I have machined that file many times and can't believe the 45 hour estimate. I would suggest you try to adjust that to a more practical estimate and then make machining decisions based on that.

Tim

Chiefmedic
Posts: 37
Joined: Sat Sep 11, 2010 8:25 pm

Re: Starting and Stoping Middle of G Code

Post by Chiefmedic »

Tim ~
Thank You for your reply. The measurments of the project are as follows: W=12" Length = 24" Thickness =10/4. I wanted to use a 0.0625" Ball nose for the final pass, perhaps I should change to a 0.125" Ball Nose. I was just trying to get as much detail as possible, so that when I finish sanding the project, I will have some detail left. I just ran the project in Cut3D using a 0.125" BN for the finish bit, and it cut the estimated time to 9 hours 34 minutes.

Dave

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Buc
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Location: Waterford, PA

Re: Starting and Stoping Middle of G Code

Post by Buc »

Dave,

I ran a Last Supper similar X and Y dimentions but .750 thickness. I use a .250" BN for roughing and .125" BN for finishing. The 125" BN was a new bit when I started. I believe I used about .010" stepover. It seems to me that it took 6 to 7 hours to finish. The material I used was a piece of Ash, little or no sanding. I was well pleased with the results. Don't forget to sign the back.

Buc
I have not failed. I've just found 10,000 ways that won't work.

Thomas A. Edison

The Only Easy Day Was Yesterday

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Buc
Posts: 548
Joined: Mon Aug 16, 2010 9:34 pm
Location: Waterford, PA

Re: Starting and Stoping Middle of G Code

Post by Buc »

This is the edit for the PP to tape split your tap file. Try it and use it with caution. I'm not responsible if you screw up.


TAPE_SPLITTING = 100000 200 "%s_%d.tap" 0 "NO"

Below is a snip as to where it is edited into the PP. I suggest you make a copy of your PP, add the edit and save it as another PP. I do this with Aspire, not sure it will work in cut 3d.

The 100000 number controls the amount of split. You can edit this number to one of your choice. the 200 number is a tolerence number it will split your file within 200 lines of 100000.

I make a new folder, name it to my liking and save the tap file to it. It will number the files, easier to find your tap files.

Buc
Attachments
tape split
tape split
I have not failed. I've just found 10,000 ways that won't work.

Thomas A. Edison

The Only Easy Day Was Yesterday

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