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start in middle of program #pcbgcode #gcode

Leonard Wohlsdorf
 

Hi All, Getting better at my board cutting and soon will make my first board. I have a question I was wondering is there a way I can start up my gcode at a place further into the code ? I have found that I need to add a M0 command to get my drills into the  too holder. M06 command is not recognized for the tool change so I was going to just add a tool change location command then pause put the bit in the go back to the drill commands and continue. I have a pretty good board cut but with no holes. I have to reset my x0.0 y0.0 since I had to leave the shop. I would like to be able to skip the cutting and go to the line that starts my drilling. Just starting out there are many questions most of which I was able to find the answer. Thanks for your time, Len

Leonard Wohlsdorf
 

Hi all, I guess I must be asking a unanswerable question. When I am using my gcode in the  cnc program can  I just rerun a portion of the code again without starting from the beginning? Anyone know if this is possible? Len

Art Eckstein
 

Len,
In my experience, the answer is "maybe" LOL

A lot depends on the controller that your using to run the code. Some will do a decent job of starting in the middle of the code (as long as you don't try restarting in a G02 or G03 code. Start it at a G0 or G1).

From what I have read Mach does not like starting in the middle of the code, but YMMV. Best way to find out is do a test run.

Country Bubba

At 9/13/2018 12:14 PM, Leonard Wohlsdorf wrote:
Hi all, I guess I must be asking a unanswerable question. When I am using my gcode in the cnc program can I just rerun a portion of the code again without starting from the beginning? Anyone know if this is possible? Len

Dan.Staver
 

I have to do this because my Nomad hangs with the latest software driver.
So, I just record the line number it hangs on, go backwards until I find the nearest tool down command, then edit out the gcode file lines in-between. I keep the startup lines at the beginning where it spins up the tool, then delete lines after that until the tool down line I previously mentioned.

Dan

Dan Staver
Tave Tech Corp.
3130 Hollycrest Dr.
Colorado Springs, CO 80920
+1-719-359-5352 - office
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W3QDO

On Sep 13, 2018, at 11:31 AM, Art Eckstein <art.eckstein@...> wrote:

Len,
In my experience, the answer is "maybe" LOL

A lot depends on the controller that your using to run the code.  Some will do a decent job of starting in the middle of the code (as long as you don't try restarting in a G02 or G03 code.  Start it at a G0 or G1).

From what I have read Mach does not like starting in the middle of the code, but YMMV.  Best way to find out is do a test run.

Country Bubba

At 9/13/2018 12:14 PM, Leonard Wohlsdorf wrote:
Hi all, I guess I must be asking a unanswerable question. When I am using my gcode in the  cnc program can  I just rerun a portion of the code again without starting from the beginning? Anyone know if this is possible? Len




kcress1x@sbcglobal.net
 

Hi Len,

Yes and no. If your G-code is absolute then that would be easily possible because each statement would stand on its own. "Go here" "Do this". However 99% of code generated by other programs use relative moves that use the prior position as a reference. So instead of "Go here" it becomes "Move a little more".

You should be able to see that if you stop G-Code execution, back up a bit and Go the next instruction will likely be "move a little more" from wherever the tool is at right now instead of where it would've been just before reaching that same instruction in normal execution.

What this means is normally, no, you can not just back up and redo.

If you want to do that you need to learn enough about G-Code that you can recognize the absolute moves that are lightly sprinkled about in most G-Code and back up specifically to that point in the code before, "continuing from here".

If there are no absolute moves (rare) then it's easiest to just re-run the entire job.

---Keith---

Leonard Wohlsdorf
 

Thanks to Art, Dan, and Keith for your responces. Why  I asked this question was during a recent board cut I found that a small section did not cut quite deep enough due to the board having a slight low spot. I am experimenting in how close I can cut the just the copper off without losing much FR4. It would be nice if I could find just where my code was describing this area cut and recut at a lower z just in this area. I have been able to use autoleveling with my grblControl program for most of my boards so far and have some nice boards but on this particular board I used a .5mm endmill and had most of the board cut very finely removing just the copper, wow looking good!!! Ooops there was just a small area with contours which did not cut deep enough. Well I set the depth just alittle deeper and reran the whole program which has quite some detail so slowed me down just a bit. I would like to copy the blocks of code that details this area to a small new program then reset. Use my limits switches that set my home position which I use to position my (0,0) at my lower left mounting hole and then recut lowering my z to remove the last bit of copper.
Has anyone tried this? Thanks again, Len

Brett Pound
 

I have edited the output of PCBGCode. It is just text commands at the end of the day, so any text editor can do what you want. You just need to be able to read it, and understand what to do - totally an exercise for the reader :)