Restart print after finish (autonomous fabrication mode)


Hi everyone,

I've been looking for a while now but haven't found an easy solution yet.
I would like to automatically remove the part from the construction platform after a part has been printed and then print the same part again.
I think removing the finished part is possible with an Octorpint script after finishing a print job but how do I restart the print job?
I would also need a counter for the repetitions if possible.

Is there a way to run the print job using MQTT?

Thank you for your help


What a coincidence. I was just discussing with a friend the other day a way to remove a print from my printer without actually being there myself to do it

My plan involved a robot arm, a spatula, a hammer, and Cables bionic left eye

What would your idea be ?

I'll let somebody else answer the MQTT thing


You're gonna need a lot more than that to remove a print from my printer. Probably a sonic jibber jabber thingy (those vibrating tools you use to cut stuff like baseboards & drywall, whatever they're called).


Holy vibrating jackhammers Batman !

That's a GREAT idea !

My motorcycle mechanic uses one of those ultrasonic parts washers that you just drop the part into the vat, and the vibrations translate thru the medium of the water to vibrate anything even potentially loose from the parts

Now, we wouldn't have the water to use as a medium, but, I wonder if the vibrations from an ultrasonic signal (or Motley Crue, played really loud), sent thru a surface transducer (very firmly attached to the print bed) could just shake loose a recently printed part from the bed

I wish I had thought of that !

Unfortunately, I don't have one of those in my parts bin, but, I'm sure as heck gonna order one and try it

Thanks !!!


one of those ultrasonic parts washers

"This old Tony" has you covered


Cool video. That's probably closer to what you were talking about (the cutter), than what I was talking about. My idea was hoping to vibrate the whole print bed until the part just got tired of trying to hold on, like that time we were driving down that dirt road while I was laying on the roof trying to hang on

Not quite sure how to attach the transducer to the bed tho. First of all, I don't wanna drill any more holes in the bed, and secondly, any screws I used would probably vibrate out in the first place (Maybe something like JB Weld would stand up to the heat and vibration) and thirdly, it needs to be thin enough that I can mount it UNDER the bed, and out of the way of the thing sliding back and forth. I just measured it, and I've only got a 17MM space in between the bed and the frame. The problem with that is that I don't know if anything that small would have the OOMF to sufficiently vibrate the bed enough to convince the plastic to let go

I am willing to try tho, so, I just ordered something that, if it doesn't work I will have at least found a new use for my printer by turning it into a speaker


The BlackBelt 3D printer prints at a diagonal so the belt just moves each part away from the hotend assembly, cooling as they go. The part eventually is convinced to remove itself due to the abrupt angle change near the end of the belt, where it drops into the next conveyor or into a bin.

My own take on this was to consider a Lazy Susan style of print bed which would simply rotate a full 360 degrees by command. You'd print a part at the back of the printer, move the hotend out of the way, rotating the part into the path of a spatula at a 5-degree angle from the bed. It would work for me since I don't have a heated bed and I'm using BuildTak. For anyone else, they'll likely also need to cool the part and the bed to ambient to get some break-away.

It would also be prudent to have some sort of "high pusher", if you will. This would be something above the edge of the spatula that would apply pressure at the top of the part, convincing it to be knocked over rather than stubbornly marching forward as the bed spins.


I'm currently printing an 8 inch turntable for my 3D scanner. I can't wait to try to get THAT off the print bed

It'll probably be easier to just buy a new printer


If the print bed's removable, the freezer is your friend for removing big/thin parts.


I was thinking about getting some canned air and turning the can upside down and just dowsing it

Should pop right off, as long as it doesn't shatter into a thousand pieces


I also have a thin spatula. For me, I begin with some diagonal twists on the bed while listening to that sound that the part is separating from the BuildTak. If I can get the spatula under an edge/corner I know it's all downhill from there. You just work around the edge very slowly and it eventually gives up.

For thin carbon fiber parts it's more of a battle. The plastic really is unforgiving and doesn't want to bend. Usually a knife blade is all that can be wedged in. Then the spatula goes in under the knife blade and I repeat as I would have before.


Actually, my question was not about solving the mechanical problem, but I can say a few words about it.
I know the BlackBelt printers and my idea to remove the part is quite similar to Balckbelt's idea.
The difference is that I will only use the belt to remove the part and not as an axle.
I want to use a metal belt that I pull over a heated magnetic bed.
As soon as I am a bit further with the construction I can show you more pictures.

At the moment I am interested in how I can get Octorpint to restart the program after completion.
Are there any suggestions?



I came across a similar project today.

However, I don't want to use the belt as a replacement for an axis, as on some videos, but only use the belt to remove the part after printing.

As can be seen on the project website, there is also a software solution for a print queue.
However, I would like to do this somehow with Octoprint. At the beginning only the same part several times, later also different parts one after the other.


After a print job is completed, the file is still selected. Assuming that there are no parts on the bed to get in the way of a G29 autolevel, for example, then one would need to just restart the job from the API.

Start a job

POST /api/job HTTP/1.1
Content-Type: application/json
X-Api-Key: abcdef...

  "command": "start"


  • you have a rock-solid mechanism for removing the last part
  • you'd probably want a delay mechanism to allow the part to be completely removed before resuming
  • you have a filament run-out detection going on so that it won't "air-print" for days.
  • you might need some way of counting down the parts, as printed

Since I like the Gcode System Commands plugin, I think I would create a shell script, associate it with an OCTO999 command and have that do a delay followed by kicking off the job again via curl. This OCTO999 command could be in the gcode file itself or in OctoPrint's gcode which runs at the end of a completed job.