# Stop and continue 3D printing

How to successfully pause 3D printing and turn off the printer and the next day, continue to print the model?

• Do you know when you want to pause it when you start the print? I completed a failed print once by measuring its height and removing all already printed segments from the g-code file. Worked reasonably well. – towe Jul 11 at 10:07
• You could use an M0, M1, or G4 command after a non-printing move (preferably just after a layer change and move to home) if your setup allows. – Davo Jul 11 at 15:08

If you enable M413 in Marlin firmware, the printer will write a resume printing file to SD card e.g. every layer.

From M413 - Power-loss Recovery documentation I quote:

Enable or disable the Power-loss Recovery feature. When this feature is enabled, the state of the current print job (SD card only) will be saved to a file on the SD card. If the machine crashes or a power outage occurs, the firmware will present an option to Resume the interrupted print job. In Marlin 2.0 the POWER_LOSS_RECOVERY option must be enabled.

This feature operates without a power-loss detection circuit by writing to the recovery file periodically (e.g., once per layer), or if a POWER_LOSS_PIN is configured then it will write the recovery info only when a power-loss is detected. The latter option is preferred, since constant writing to the SD card can shorten its life, and the print will be resumed where it was interrupted rather than repeating the last layer. (Future implementations may allow use of the EEPROM or the on-board SD card.)

This means if you cut the power you can resume the print layer, the only problem is that the part must remain attached to the plate, if it comes loose it is hard to resume printing. This feature is now commonly found on printers these days.

The regular pause and resume functionality of the printer will not work when the power is cut over night, i.e. no recovery file is written in such a case.

• I have never understood the votes cast on this sub. IMO This is the perfect answer, all the others are just tinkering (mine included)! – Valmond Jul 12 at 8:01
• @Valmond, thanks, remember voting is key! Top answers will float to the top. Note that this answer, although it works, it is not perfect, this is not what the resume on power outage has been designed for. There is just no alternative if it has to include a shutdown as per request of the OP, this is the best answer I could think of including powering down. – 0scar Jul 12 at 8:29
• Yeah guys, vote, but when you downvote, also tell why or it only comes off as an angry down-vote spree. – Valmond Jul 12 at 10:55

I recommend that you don't turn off the printer and resume the next day. If the heat bed cools down the part could become unstuck. The printer must be kept hot for the entire time that you need to print; unless it's PLA which tends to be more forgiving. Also Turning off the printer and turning it back on will cause it to loose it's position. Each time you home the axis of the printer it could home in a slightly different location. If you resumed the print under those conditions it would leave a clear line on the outer walls that is indicative of the layers not lining up properly. Lastly, if you let the nozzle ooze for period of time, you will have to purge the nozzle before you could print again. In this regard be prepared for some air printing for the first few movements. Depending on what you are printing, this could result in a build failure.

Needless to say, people have been able to recover a print under power off/failure conditions, but that's not a strategy to 3d printing. Those were mitigation efforts to exception cases.

1) Cut the model up in several parts and print one each day. Remove each part every day and in the end, glue them all together.

2) Cut the model up in several parts and each day, add a G-code to the file to be printed so it lowers the heat-bed and thus starts to print on top of yesterdays print. This cannot be used when the printer is auto-calibrating as the printer-head would crash into the already printed part. It would probably be tricky.

3) Pause the printer in the evening, then resume next day (don't forget to lower temperatures and rise them again tomorrow).

• Well, the lowering of the build plate (or raising of the print head) is mixed in in the GCode so if you skip it, you would have to add it in "one go" before the printing. – Valmond Jul 11 at 15:19

Some printers have built-in functionality for resume after power-loss. I believe this is a standard part of the Marlin firmware now; I know the Creality Ender 3 has it and I don't believe it was a nonstandard addition (and if it was, their source was released in accordance with the GPL anyway, so it could be merged). So if you printer doesn't already have the functionality, but is amenable to a firmware upgrade/replacement to a version of Marlin that does, it should be possible to get it.

I have an Ender 3, but I haven't tried this feature so I can't speak to how well it actually works.

I already answered once more directly, but I think a better answer might be a frame challenge: design your model to avoid extremely long print times. Even if you didn't have all the problems of pausing and resuming to deal with, which include:

• warping and detachment from bed due to loss of bed heat
• possible motion of stepper motors while unpowered
• extrusion problems due to loss of material to oozing
• ...

you still have the fundamental risk that something goes wrong during the print, which increases significantly with the overall print duration.

There are lots of ways to design your model to be printed in multiple parts that don't amount to just "cut it at height intervals and glue the result". Glue isn't a terribly good solution, at least not by itself; it's hard to ensure perfect alignment, and creates points with different thermal and mechanical properties that are likely to break. Other options include:

• Snap fits, either reversible or permanent.
• Peg/hole press fit.
• Slide-in tension fit.
• Threaded interfaces. These can easily be directly between your parts if the parts are rotationally symmetric or orientation doesn't matter. If it does matter, you can design the threads to stop at the right point but it's more work.
• Threaded holes in one part, metal or 3D-printed bolts through the other to attach it.

In addition to letting you print the object in steps rather than all at once to reduce the chance/cost of failure, these techniques also allow you to print different parts of the object in different orientations, taking advantage of the orientation for ease of printing without supports, or for obtaining stength in the directions your object will be subjected to stresses in.

Most (really all) of the above can also be made permanent with glue, if you desire.