âDo not leave your 3D printerâ unattended. Sure, thatâs good practice, especially with ones that have, you know, questionable cable management or cheap components, but are you really going to babysit the machine the entire time? I donât think so. Especially when things like noise, particle emissions, and printing smells are something you donât really want to have right next to you. So OctoPrint is actually a very good first step for that – it allows you to remote-control a 3D printer from anywhere you have access to the same network your printerâs Raspberry Pi is on. But you still have to actively watch the webcam stream and you canât leave the house or youâre going to lose the connection. So thatâs where the Spaghetti Detective comes in, and it promises to solve both those problems. Itâs a web service that you can use to check in on your prints from anywhere around the world and tweak or stop things if you need to, but itâs also an AI that watches that webcam feed for you and will either just alert you or actually halt the print if thinks thereâs something going seriously wrong. So letâs see how good an AI can be at detecting print failures and how useful the Spaghetti Detective really is.
Set Up
The Spaghetti Detective, is, thankfully, really easy to set up. Itâs two components, one is the âcloudâ web service, which also does the AI image processing, and you can either use the one that the folks from the Spaghetti Detective are providing or set up your own server if you want to. Itâs open-source software, after all. And the other component is an OctoPrint plugin, which basically just remote-controls OctoPrint itself, which I think is awesome because, first of all, why reinvent the wheel and create a whole other printer server when thereâs already a perfect solution available in the form of OctoPrint, but second of all, you then also get a fully-featured OctoPrint server that, of course, is fully functional for printer control, file management, etc on your local network.
The setup is super quick if you already have OctoPrint running, you create an account on the Spaghetti Detective website, install the plugin into OctoPrint, and then you just copy-paste a secret key from the website to the plugin and thatâs it! If you want to start a print, you can either use the OctoPrint interface and do it the ânormalâ way and the Spaghetti Detective will pick up that your printer is now printing something, or, on the paid plans, you can also upload and start prints through the web interface. And after that, just choose if you want the Spaghetti Detective to stream and watch the print and whether it should pause or just alert you if it thinks somethingâs wrong, and thatâs it!
Free and Paid Plans
So I guess we should briefly talk about the free and paid options. Like I said, the Spaghetti Detective is an open-source project, so, if you want to, you can use all the features without spending a single penny. But thatâs going to entail setting up your own server, maintaining that as well as making sure thatâs securely available on the internet if you want to access it remotely. Also, apparently, the actual processing thatâs happening with the print failure detection AI is a bit intense and too much for the little Raspberry Pi thatâs already trying to keep up with consistently feeding data to the printer. So if you donât want to manage your own server, the Spaghetti Detective offers a few different convenient paid tiers that give you access to more features as you go.
There is a free tier, which lets you remote-control the printer and gives you a low-framerate webcam stream as well as 10 hours per month of the AI watching your prints and intervening if you want it to. You can actually earn more watch hours by for example giving feedback on your prints. The free tier lets you use the remote control and webcam feature as much as you want, which I think is pretty awesome, but for the compute-intensive AI watching feature, there is a limit. Uploading or starting a print through The Spaghetti Detective is limited to the paid tiers, and those also include a higher framerate live webcam stream as well as a larger allowance of AI watch hours.
To me, just getting the peace of mind of being able to check in on your prints if you decide to leave your printer while you go out and being able to actually intervene and stop the print if you need to is already a huge deal, and you actually get that in the free plan already, but for the AI features, whether paying for them is worth it really depends on whether they actually work. So Iâve done some testing. Iâve actually combined this with my testing for the Artillery X1 review, so youâre going to see that printer as my guinea pig in all these time-lapses.
First Test Print
So for the print failure detection AI, it really needs to do two things for it to be useful, and thatâs that it should correctly detect prints that are ok as âokâ, so no false-positive alerts, because if you have The Spaghetti Detective set to pause whenever it senses an issue, that would cause more harm than it solves when it pauses too often; but of course, also, it needs to be able to correctly identify issues when they do happen and take action, so, no false negatives.
And just to get my bearings, I started with the Strata Miniatures Rogue that you also saw in the last video, this time scaled to 300% and sliced with the Slic3r slicer that Artillery supply for their X1. And this one lit up like a Christmas tree. So, The Spaghetti Detective highlights the areas that it thinks are failing, and that was pretty interesting to see, because, yes, the auto-generated supports by Slic3r are not that great, well, theyâre actually pretty bad, and those did topple over and cause some spaghetti, which, as far as I can tell, was correctly detected, but it also detected issues on just random high-detail areas or just glossy top surfaces that were actually fine.
Honestly, I would rather have it detect too much and alert me one too many times than just overlook an is sue and waste filament or even damage the printer by not intervening.
Printing Benchies with added Issues
So, ok, there was a lot going on in that print, at this point Iâm thinking itâs maybe a bit too sensitive, which would be fine, so letâs step it down a notch and just print Benchies. Like, if this neural network was trained on anything, it better know what a 3D Benchy should look like. I printed two good ones, with no issues added, and those correctly detected as being flawless.
So far, so good, so next I tried some that actually had issues. For example, a Benchy thatâs extruded with a 30% extrusion multiplier, so itâs only getting 1/3rd of the filament the print would actually need to print well.
And according to The Spaghetti Detective, this is perfectly fine, too. Honestly, I am surprised by how well this is coming out, but the holes in the surface were clearly visible even in the low-resolution webcam feed. Okay, so maybe it was the contrasty lighting that threw it off, so I added more lights, but that also didnât change anything. According to The Spaghetti Detective, this is still a perfectly fine print.

Okay, so maybe a layer shift would get it excited, so I prepared a gcode that intentionally shifts the Y axis at 10mm print height, starting with a 5mm offset, which, actually, wasnât that much of an issue for the printer, and The Spaghetti Detective also did not detect it; next 10mm, which has some visible spaghettitization going one, also, nothing detected, so I upped that to 25mm, which basically takes the entire upper half of the Benchy and throws it aboard, and, finally, that was detected as maybe being a bit of a problem.

Trying to improve Error Detection
Now, of course, there are some technical limitations that play into how well the software is going to be able to recognize whatâs going on. The biggest limitation, obviously, is the camera, and not this specific camera, this is a 1080p one thatâs actually quite decent, but the fact that it is a camera. Itâs only ever in one spot, it doesnât see in stereo as we do, and when you try to get the whole print bed into frame, details that would determine whether a print is failing or successful do become pretty small and hard to pick up. And thereâs a lot of motion blur when the print bed moves while the camera is grabbing a frame. Thereâs also the issue of lighting – you want everything to be evenly lit, but not so evenly that you stop seeing any sort of detail.
So, much of my testing my focus on trying to see whether I could improve the error detection rate by giving The Spaghetti Detective better data. I added lighting from the direction the camera is looking in, I mounted the camera to the print bed so that there wouldnât be any motion blur and I increased the resolution OctoPrint is getting from the camera from the default 640x480 pixels to 1280x720 – aka. 720p.
And none of all this seemed to make a difference. With my human eyes, I could basically see every failure happening on the camera feed – which is the same feed The Spaghetti Detective is looking at, but even under what I would consider best-case scenarios, the AI was barely ever recognizing that there was anything wrong.
Now, thatâs not to say that it never works, it picked up some of the more severe failures and the Spaghetti Detective website does showcase a few failing prints that are correctly identified, but it always seems to be at a point where itâs already pretty far gone. At that point, youâre really just protecting the printer from damaging itself.
Useful or not?
But what Iâve asked myself while using The Spaghetti Detective is, you know, even if it was 100% accurate and reliable, what are you going to do with that information that your print is failing? Youâre not going to save the print, all you can do is to stop and start over, this time hopefully having fixed what was causing the problem, but itâs really just reacting to something that has already happened. Best case, vs. checking on your printer every two hours or so through OctoPrint, would be saving a couple grams of filament, getting to restart the print a bit faster and possibly less cleanup on the printer.
Sure, it could be a nice, extra safety net if youâre printing overnight or simply donât want to check the print that often, but with how unreliable the detection has been for me so far, I really donât know if Iâd be sleeping any better. The AI really still needs a lot of improvement and more training.
But three features that do make The Spaghetti Detective quite useful already – and you actually get those, currently, on the free plan.
They are, like I mentioned, being able to watch the print from anywhere, then, since youâre already sending a livestream of your print to The Spaghetti Detective, you can re-watch all your past prints and download a timelapse from the webcamâs perspective, which is neat, but thatâs also built into OctoPrint now, and lastly, they are experimenting with offering an OctoPrint tunnel, which would allow you to securely access the full OctoPrint interface from basically anywhere, but itâs still in beta and managed to completely crash my OctoPrint 8 hours into a two-day print the first time I tried it. So, maybe use that feature sparingly until itâs fully tested and released.
Now, for the paid options⊠well, there is a one-month free trial where you can use all the features without any limits, and you should definitely use that to check if The Spaghetti Detective can detect the sort of issues youâre expecting and whether that extra information is useful for you. I will mostly be using it for remote webcam viewing.
Raspberry Pi Setup: Raspberry Pi 4
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