filament

109 Articles

Over-Engineering An FDM Spool Holder From Prusa Mk4S Remains

June 5, 2026 by 3 Comments

Unlike resin printers where you generally just pour the fresh resin into the easily accessible vat, FDM printers need to squirrel away at least one spool and its requisite holder somewhere. For bed slingers this generally means a top-mounted spool holder, while for CoreXY enclosed printers they can appear on the sides, top or – inexplicably – on the back. While a side-mounted spool is often convenient, access to the side can still be blocked, in which case you do what [3D Maker Noob] did and over-engineer a fancy top-mounted spool holder.

The problem started after converting a Prusa Mk4S to a Core One using the conversion kit, which changes the position of the spool, forcing him to work around not having access to the right side of the machine where the default position is. After a first version using many of the left-over parts of the original Mk4S to create a fancy box-shaped spool holder, he proceeded to upgrade it as detailed in the video. All project files and instructions are available on Printables.

The result is a box you stack on top of the printer somewhat like a multi-spool box, just flatter and with a flippy lid on the front from which a rail slides out with the magnetically attached spool holder. A spool holder which you naturally can further customize to fit different spools. Even if over-engineered, you can’t deny that it would fit in confined spaces and looks pretty good while doing its job.

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Is That Ancient Reel Of PLA Any Good?

February 10, 2026 by 48 Comments

When it comes to knowledge there are things you know as facts because you have experienced them yourself or had them verified by a reputable source, and there are things that you know because they are common knowledge but unverified. The former are facts, such as that a 100mm cube of water contains a litre of the stuff, while the latter are received opinions, such as the belief among Americans that British people have poor dental care. The first is a verifiable fact, while the second is subjective.

In our line there are similar received opinions, and one of them is that you shouldn’t print with old 3D printing filament because it will ruin the quality of your print. This is one I can now verify for myself, because I was recently given a part roll of blue PLA from a hackerspace, that’s over a decade old. It’s not been stored in a special environment, instead it’s survived a run of dodgy hackerspace premises with all the heat and humidity that’s normal in a slightly damp country. How will it print?

It Ain’t Stringy

In the first instance, looking at the filament, it looks like any other filament. No fading of the colour, no cracking, if I didn’t know its age it could have been opened within the last few weeks. It loads into the printer, a Prusa Mini, fine, it’s not brittle, and I’m ready to print a Benchy.

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Silica Gel Makes For Better 3D Prints

January 22, 2026 by 34 Comments

It’s possible to improve your 3D prints in all kinds of ways. You can tune your printer’s motion, buy better filament, or tinker endlessly with any number of slicer settings. Or, as [Dirt-E-Bikes] explains, you could grab yourself some silica gel.

If you’re unfamiliar with silica gel, it’s that stuff that comes in the “DO NOT EAT” packet when you buy a new pair of shoes. It’s key feature is that it’s hygroscopic—which means it likes to suck up moisture from the atmosphere. When it comes to 3D printing, this is a highly useful property—specifically because it can help keep filament dry. Over time, plastic filament tends to pick up some moisture on its own from the atmosphere, and this tends to interfere with print quality. This can be avoided by storing filament in a sealed or semi-seaeled environment with silica gel. The gel will tend to suck up most of the moisture from the air in the sealed container, helping to keep the filament drier.

[Dirt-E-Bikes] does a great job of explaining how best to integrate silica gel with your filament spools and automatic material changer (if you have one). He also explains the value of color changing silica gel which indicates when the material is saturated with water, as well as how to dry it out for reuse. You can even combine some of the color changing beads with the more common plain white beads recycled from your shoe boxes, since you only need a few colored beads to get an idea of the water content.

We’ve explored other filament drying solutions before, too. Video after the break.

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The Trials Of Trying To Build An Automatic Filament Changer

August 11, 2025 by 17 Comments

Running out of filament mid-print is a surefire way to ruin your parts and waste a lot of time. [LayerLab] was sick of having this problem, and so sought to find a proper solution. Unfortunately, between off-the-shelf solutions and homebrew attempts, he was unable to solve the problem to his satisfaction.

[LayerLab] had a simple desire. He wanted his printer to swap to a second spool of filament when the first one runs out, without ruining or otherwise marring the print. It sounds simple, but the reality is more complicated. As an Australian, he couldn’t access anything from InfinityFlow, so he first attempted to use the “auto refill” features included on the Bambu Labs AMS 2. However, it would routinely make filament changes in outside wall areas of a print, leaving unsightly marks and producing poorer quality parts.

His next effort was to use the Wisepro Auto Refill Filament Buffer. It’s a feeder device that takes filament from two spools, and starts feeding the backup spool in to your printer when the primary spool runs out. Unfortunately, [LayerLab] had a cavalcade of issues with the device. It would routinely feed from the secondary spool when there was still primary filament available, jamming the device, and it didn’t come with a proper mounting solution to work with consumer printers. It also had bearings popping out the top of the housing. Attempts to rework the device into a larger twin-spool rig helped somewhat, but ultimately the unreliability of the Wisepro when changing from one spool to another meant it wasn’t fit for purpose. Its feeder motors were also to trigger the filament snag cutters that [LayerLab] had included in his design.

Ultimately, the problem remains unsolved for [LayerLab]. They learned a lot along the way, mostly about what not to do, but they’re still hunting for a viable automatic filament changer solution that suits their needs. Filament sensors help, but can only do so much. If you reckon you know the answer, or a good way forward, share your thoughts in the comments. Video after the break.

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I Gotta Print More Cowbell

July 3, 2025 by 5 Comments

Since the earliest days of affordable, home 3D printers, the technology behind them has been continuously improving. From lowering costs, improving print quality, increasing size and detail, and diversifying the types of materials, it’s possible to get just about anything from a 3D printer today with a minimum of cost. Some of the things that printers can do now might even be surprising, like this upgrade that makes [Startup Chuck]’s 3D printer capable of printing realistic-sounding cowbells out of plastic.

The key to these metal-like prints is a filament called PPS-CF which is a carbon fiber-reinforced polyphenylene sulfide, or PPS. PPS-CF has a number of advantages over other plastics including high temperature tolerance and high dimensional stability, meaning its less likely to warp or deform even in harsh environments. But like anything with amazing upsides, there are some caveats to using this material. Not only does the carbon fiber require more durable extruder nozzles but PPS-CF also needs an extremely hot print head to extrude properly in addition to needing a heated bed. In [Startup Chuck]’s specific case he modified his print head to handle temperatures of 500°C and his print bed to around 100°C. This took a good bit of work just to supply it with enough energy to get to these temperatures and caused some other problems as well, like the magnet on the printer bed demagnetizing above around 75°C.

To get to a working cowbell took more than just printer upgrades, though. He had to go through a number of calibrations and test prints to dial in not only the ideal temperature settings of the printer but the best thicknesses for the cowbell itself so it would have that distinct metallic ring. But cowbells aren’t the only reason someone might want to print with carbon-reinforced materials. They have plenty of uses for automotive, chemical processing, high voltage, and aerospace applications and are attainable for home 3D printers. Just make sure to take some basic safety precautions first.

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3D Filament lizards show decomposable joints

Sustainable 3D Prints With Decomposable Filaments

May 30, 2025 by 24 Comments

What if you could design your 3D print to fall apart on purpose? That’s the curious promise of a new paper from CHI 2025, which brings a serious hacker vibe to the sustainability problem of multi-material 3D printing. Titled Enabling Recycling of Multi-Material 3D Printed Objects through Computational Design and Disassembly by Dissolution, it proposes a technique that lets complex prints disassemble themselves via water-soluble seams. Just a bit of H2O is needed, no drills or pliers.

At its core, this method builds dissolvable interfaces between materials like PLA and TPU using water-soluble PVA. Their algorithm auto-generates jointed seams (think shrink-wrap meets mushroom pegs) that don’t interfere with the part’s function. Once printed, the object behaves like any ordinary 3D creation. But at end-of-life, a water bath breaks it down into clean, separable materials, ready for recycling. That gives 90% material recovery, and over 50% reduction in carbon emissions.

This is the research – call it a very, very well documented hack – we need more of. It’s climate-conscious and machine-savvy. If you’re into computational fabrication or environmental tinkering, it’s worth your time. Hats off to [Wen, Bae, and Rivera] for turning what might otherwise be considered a failure into a feature.

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Bar of conductive filament with leds and a battery

Putting Conductive TPU To The Test

March 15, 2025 by 3 Comments

Ever pried apart an LCD? If so, you’ve likely stumbled at the unassuming zebra strip — the pliable connector that makes bridging PCB pads to glass traces look effortless. [Chuck] recently set out to test if he could hack together his own zebra strip using conductive TPU and a 3D printer.

[Chuck] started by printing alternating bands of conductive and non-conductive TPU, aiming to mimic the compressible, striped conductor. Despite careful tuning and slow prints, the results were mixed to say the least. The conductive TPU measured a whopping 16 megaohms, barely touching the definition of conductivity! LEDs stayed dark, multimeters sulked, and frustration mounted. Not one to give up, [Chuck] took to his trusty Proto-pasta conductive PLA, and got bright, blinky success. It left no room for flexibility, though.

It would appear that conductive TPU still isn’t quite ready for prime time in fine-pitch interconnects. But if you find a better filament – or fancy prototyping your own zebra strip – jump in! We’d love to hear about your attempts in the comments.

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