Help needed with GCode editing problem

aidar

Hi. Looks like you put your extrusion in absolute mode and then :G1 X209.134 Y63.784 E1472.39774. Means printer have to extrude almost 1.5 m of filament before it can continue. So you should put your extruder to the point you paused the print with, something like this:
G1 E4.00000 F6000.00000
G1 F2400
G92 E14xx.xxxxx (whatever numbers you had there instead of x)
G1 X209.134 Y63.784 E1472.39774

Just my guess, actually i never had tried something like this.

SplatHammer

Ha! Of course, the the extruder value is constantly incrementing as the print progresses and as I just started the file part way through it would just sit there until it had extruded filament equal to the total for the first part of the print. That was really stupid of me! Ok, I will give it a try.

Jacotheron

I agree with @aidar - the issue is your extrusion being on Absolute mode (M82) and you should set your extrusion to relative mode first (M82) , but also your "G92 E0" E parameter should be changed to be very close "1472.39774" - the distance it is at before it needs to continue.

Right now, with your current gcode, it tells the printer to do the following:

Move to location X209, Y63 - this is what you have put in and is fine.
Move to location X209.134, Y63.784 at a speed of (F, previous value used if not present) 2400mm/min and extrude a total of 1472.39774mm of filament while doing it.
Move to location X223.302 Y49.616 at the same speed as before, while extruding a total of 1476.18263mm of filament.

As you can see, in the first move, it only moves a fraction of a mm, while having to extrude so much filament (the total that was already used, or the total since the last time the slicer Zero it) so due to your extruder max speed and acceleration, this takes a long time, and the movement speed (in X and Y) is reduced since the Extruder is the speed limiting factor. Then when that is done, in the new movement, it have to extrude the same amount again.

What you can do to correct it:

Insert the correct extruded amount up to that point, using G92 and set the extruder to be in the same mode (absolute vs relative as your slicer).

When I notice (a) skipped step(s) like this late in a print, I would not stop the print, but rather pause it - the default pause script save current position, and simply returns to it on resume. While it is paused, Home X and Y before continuing the print.

With it being in a pause, we can do a few nice things, including manually change filament, home X and Y, prime the nozzle etc. before simply pressing the resume and it will continue where it left off (and since after the Home it knows where it is, now in the right position). I did test it with a non-vital print, and recommend testing it on a non-vital print first to ensure you know how it works and fix possible issues in the scripts, before it causes more damage than it solves.

SplatHammer

@aidar Thanks a load! It worked perfectly! Thats a lot of expensive filament saved.

SplatHammer

@jacotheron Thanks for the information, it will save me a lot of grief! I knew you could change filament but I didnt know I could redo the homing, I thought issuing any commands would make it lose track of what it was doing. that really useful, thanks!

dc42

Also worth noting is that any time you press Pause, unless you are using really old firmware then a resurrect.g file is created, to make it possible to resume the print later. But you should set up and test your resurrect-prologue file in advance.

wilriker

@dc42 said in Help needed with GCode editing problem:

Also worth noting is that any time you press Pause, unless you are using really old firmware then a resurrect.g file is created, to make it possible to resume the print later. But you should set up and test your resurrect-prologue file in advance.

And to add here: use M916 (without any parameters) to resume the print specified in resurrect.g.

P.S.: Also is there a specific reason you are using absolute extrusion? Relative extrusion is preferable as it will not suffer from any rounding error (as much) as absolute extrusion does. Plus in your case it would just have worked how you tried it first.

SplatHammer

@dc42 Thanks, I will check it out.

SplatHammer

@wilriker Thanks for the tips!
I didnt actually know I was using absolute extrusion! I have not seen any setting in Slic3r to select absolute/relative extrusion and this is the first time I have really edited a gcode file.
Ok, I have just checked on slic3r and found it (I think) under printer settings>general>advanced>use relative E distances When I hover over it I get a message saying "most firmware uses absolute value" I will give it a try on my next small print and see what happens!

wilriker

@splathammer Interesting and strange tool tip since even Marlin supports relative extrusion for some time now. Privacy no one has touched this text for a long time.