Saving Prints that stop half way through

[ormadorm 0]

Hello, sometimes my print just stops 1/2 or 3/4 of the way through a print. This does not happen frequently but when it does it is frustrating. I realize the best thing to do would be to prevent the print from stopping midprint but sometimes it just happens. I can open the gcode in notepad ++ and edit it with the intent to start printing where i left off. But how do I get the edited gcode back into Cura? Cura will open a .gcode file but not a .txt file. Are they not essentially the same thing? Do I have to convert the .txt into a .gcode somehow? My printer is a monoprice mini. Thanks for any suggestions.  

[gr5 2,234]

Some versions of Marlin will let you continue a failed print.

 

Anyway, typically you can keep the header part where it homes the print head and then delete everything up until the layer where you want it to start.  The one caveat is the extruder.  The extruder value is the accumulated extruder position.  So an hour into the print the position might be a few meters, say it was 2 meters it would be E2000 in the gcode.  If you scroll quickly through the gcode file you can see the E value keeps increasing very slowly throughout the file.

 

So there is a simple trick: G92.  This resets any axis position to be where it is now.  So like this:

 

G92 E2000

G1  E2001

 

The first line above tells the extruder "hey - I know you think you are at E0 but you are really at E2000 - don't extrude 2 meters of filament please."

 

The second line tells the extruder to move to 2001mm which would extrude one mm of filament.

 

So just fine the first E value (or even better the final E value deleted) and set the extruder there with the G92 command.

 

Make sure you keep the header commands that home the 3 axes and turn on the heater and such.

 

AND FINALLY TO ANSWER YOUR QUESTION.  Just save it as a gcode file and print it directly.  Cura should not be involved in any of this.

[GregValiant 1,354]

I'm getting a feeling that you are printing via the USB connection.  Is that correct?  If that is true, then when the machine stops is there any message on the screen?  "Click to RESUME" maybe?  That is a known problem when using Cura as a printing host and a particular chain of events happens in the Gcode.

 

To re-start a print - as @gr5 says, edit the file and erase the layers, skirt/brim up to your restart layer.  Along with adding the G92 line you should add a Z movement to insure that the machine moves the print head above the existing part on the plate, BEFORE the Gcode tells the printer to move in the XY.  If you are re-starting a print at say Z=35.6 and you don't move your Z first then the printer will move the head from the home position 0,0,0 in a straight line to the new start point.  Crash.  So you need to add a line like "G1 Z45.6 F2700" right after the G92 line that gr5 described and before the Gcode tells the printer to move in the XY.

 

Yes - a Gcode file is a simple text file.  When you save the file in a text editor you may have to manually get rid of the TXT name extension and type in GCODE.  You can always rename a saved text from from YourFile.txt to YourFile.gcode.

 

You have probably noticed that layer numbering in Gcode starts at 0 while layer numbering in Cura preview starts at 1.  Pay attention when deciding what layer number to actually re-start at.  It's an easy mistake to make.

Edited September 1, 2020 by GregValiant

[ormadorm 0]

Hi guys, thank you for the response. Yes I am printing using the USB connection. I dont currently have an SD card reader but I will get one. I tried renaming the .txt file to a .gcode file and it does change the file name but it does not change the file type and hence cura still won't open it. But it sounds like this problem will be solved if  I just get an SD card reader and print directly to the printer.

[gr5 2,234]

So Windows hides file extensions by default.  There should be a setting somewhere in explorer to make them visible so you can change the extension as well.  the extension is just the last 3 or 4 characters after the final "." in the filename.  It's very annoying (to me) that Windows hides this by default.

 

I often forget this because I only have to set thins once in explorer and then the computer remembers "forever".  Or until I buy a new windows computer (haven't done this in maybe 8 years?  I'm mostly linux now).

 

Anyway, I didn't realize you didn't have SD card.  So yeah once you rename the extension properly to gcode you should be (I think?) able to load it in cura and print it.  If not there's much better than cura for printing through USB cable.  I really love prontrface/printrun.  Or repetier.  Both of those are free.

[gr5 2,234]

By the way, the number of features on printrun/prontrface or repetier puts Cura to shame - Ultimaker doesn't sell printers where you can print through the USB so this feature is not as well fleshed out.  Cura is mainly a slicer.