Instant Filament Drying Satisfies An Immediate Need

July 2, 2024 by Bob Baddeley 33 Comments

Most 3D printer filament soaks up water from the air, and when it does, the water passing through the extruder nozzle can expand, bubble, and pop, causing all kinds of mayhem and unwanted effects in the print. This is why reels come vacuum sealed. Some people 3D print so much that they consume a full roll before it can soak up water and start to display these effects. Others live in dry climates and don’t have to worry about humidity. But the rest of us require a solution. To date, that solution has been filament dryers, which are heated elements in a small reel-sized box, or for the adventurous an oven put at a very specific temperature until the reel melts and coats the inside of the oven. The downside to this method is that it’s a broad stroke that takes many hours to accomplish, and it’s inefficient because one may not use the whole roll before it gets soaked again.

In much the same way that instant water heaters exist to eliminate the need for a water heater, [3DPI67] has a solution to this problem, and it involves passing the filament through a small chamber with a heating element and fan circulating air. The length of the chamber is important, as is the printing speed, since the filament needs to have enough time in the improvised sauna to sweat out all its water weight. The temperature of the chamber can’t get above the glass transition temperature of the filament, either, which is another limiting factor for the dryer. [3DPI67] wrote up a small article on his improvised instant filament heater in addition to the video.

So far, only TPU has been tested with this method, but it looks promising. Some have suggested a larger chamber with loops of filament so that more can be exposed for longer. There’s lots of room for innovation, and it seems some math might be in order to determine the limits and optimizations of this method, but we’re excited to see the results.

Studying The Finer Points Of 3D Printed Gears

June 12, 2024 by Dave Rowntree 31 Comments

[How to Mechatronics] on YouTube endeavored to create a comprehensive guide comparing the various factors that affect the performance of 3D printed gears. Given the numerous variables involved, this is a challenging task, but it aims to shed light on the differences. The guide focuses on three types of gears: the spur gear with straight teeth parallel to the gear axis, the helical gear with teeth at an angle, and the herringbone gear, which combines two helical gear designs. Furthermore, the guide delves into how printing factors such as infill density impact strength, and it tests various materials, including PLA, carbon fiber PLA, ABS, PETG, ASA, and nylon, to determine the best options.

The spur gear is highly efficient due to the minimal contact path when the gears are engaged. However, the sudden contact mechanism, as the teeth engage, creates a high impulse load, which can negatively affect durability and increase noise. On the other hand, helical gears have a more gradual engagement, resulting in reduced noise and smoother operation. This leads to an increased load-carrying capacity, thus improving durability and lifespan.

It’s worth noting that multiple teeth are involved in power transmission, with the gradual engagement and disengagement of the tooth being spread out over more teeth than the spur design. The downside is that there is a significant sideways force due to the inclined angle of the teeth, which must be considered in the enclosing structure and may require an additional bearing surface to handle it. Herringbone gears solve this problem by using two helical gears thrusting in opposite directions, cancelling out the force.

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Thermoelectric Module Keeps Printer Filament Cool And Dry

June 5, 2024 by Dan Maloney 57 Comments

Anyone who has left their car windows open during a rainstorm will tell you the best way to dry the upholstery is to crank the AC and close the windows. A couple of hours later, presto — dry seats. The same can be said for 3D printer filament, and it’s pretty much what [Ben Krejci] is doing with this solid-state filament dryer.

The running gear for this build is nothing fancy; it’s just a standard thermoelectric cooling module and a fan. The trick was getting the airflow over the module right. [Ben] uses two air inlets on his printed enclosure to pull air from the cold side of the Peltier, which allows the air enough time in contact with the cold to condense out the water. It also allows sufficient airflow to keep the hot side of the module from overheating.

Water collection was a challenge, too. Water always finds a way to leak, and [Ben] came up with a clever case design incorporating a funnel to direct water away. The module is also periodically run in reverse to defrost the cold side heatsink.

The dehumidifier lives in a large tool cabinet with plenty of room for filament rolls and is run by an ESP32-C3 with temperature and humidity sensors, which allowed [Ben] to farm most of the control and monitoring out to ESPHome. The setup seems to work well, keeping the relative humidity inside the cabinet in the low 20s — good enough for PETG and TPU.

It’s an impressively complete build using off-the-shelf parts. For a different approach to solid-state filament drying, check out [Stefan]’s take on the problem.

Building An 8-Color Automated Filament Changer

May 24, 2024 by Lewin Day 12 Comments

Multi-filament printing can really open up possibilities for your prints, even more so the more filaments you have. Enter the 8-Track from [Armored_Turtle], which will swap between 8 filaments for you!

The system is modular, with each spool of filament installed in a drybox with its own filament feeder .The dryboxes connect to the 8-Track changer via pogo pins for communication and power. While [Armored_Turtle] is currently using the device on a Voron printer, he’s designed it so that it can be easily modified to suit other printers. As it’s modular, it’s also not locked into running 8 filaments. Redesigning it to use more or less is easy enough thanks to its modular design.

The design hasn’t been publicly released yet, but [Armored_Turtle] states they hope to put it on Github when it’s ready. It’s early days, but we love the chunky design of those actively-heated drybox filament cassettes. They’re a great step up from just keeping filament hanging on a rod, and they ought to improve print performance in addition to enabling multi-filament switching.

We’ve seen some other neat work in this space before, too. Video after the break.

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Wear Testing Different 3D Printer Filaments

April 2, 2024 by Jenny List 5 Comments

Over the couple of decades or so since it started to be available at an affordable level, 3D printing has revolutionized the process of making custom objects. But as anyone with a 3D printer will know, sometimes the materials don’t quite live up to the application. There is a huge variety of available filaments to help make better prints, but which one really is the most hard-wearing? [My Tech Fun] set out to measure the resistance to wear of a variety of different 3D printed materials.

The test takes a standard print made across a variety of different materials, and several of each using different manufacturers’ offerings. These are then put on a test rig that moves backward and forward twice a second, with the test piece rubbing against a steel shaft under pressure from a 2.5 kg weight.

As might be expected, the common and cheap PLA performed the worst while PETG, PA, and TPU performed the best. But for us the interesting part comes in the variance between brands; the best PLA sample outperforms the worst ABS and nearly equals the worst of the PETG. Proof that maybe you do get what you pay for.

The whole test is well worth a watch, and if you 3D print anything that might be subjected to mechanical stress you should find it to be of interest. If comparing filaments is something you’d like to see more of, we’ve featured some tests before.

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3D Printing With (Ersatz) Moon Dust

March 27, 2024 by Al Williams 29 Comments

When the people of Earth set up bases on the moon, you can imagine that 3D printing will be a key enabling technology. Of course, you could ship plastic or other filament at great cost. But what if you could print with something you can already find on the moon? Like moon dust. NASA thinks it is possible and has been doing tests on doing just that. Now [Virtual Foundry] wants to let you have a shot at trying it yourself. It doesn’t really contain moon dust, but their Basalt Moon Dust Filamet has a similar composition. You can see a video about the material below.

It isn’t cheap, but it is probably cheaper than going up there to get some yourself. At least for now. The company is known for making PLA with various metal and ceramic materials. Like their other filaments, you print it more or less like PLA, although you need a large hardened nozzle, and they suggest a prewarmer to heat the filament before going to the hot end.

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3D Printing A Nifty Sphere Without Supports

November 26, 2023 by Donald Papp 6 Comments

[DaveMakesStuff] demonstrates a great technique for 3D printing a sphere; a troublesome shape for filament-based printers to handle. As a bonus, it uses a minimum of filament. His ideas can be applied to your own designs, but his Giant Spiralized Sphere would also just happen to make a fine ornament this holiday season.

Printing two interlocking parts and using vase mode ensures a support-free print that uses a minimum of filament.

The trick is mainly to print the sphere in two parts, but rather than just split the sphere right down the middle, [Dave] makes two hollow C-shaped sections, like a tennis ball. This structure allows the halves to be printed in vase mode, which minimizes filament use while also printing support-free.

Vase (or spiral) mode prints an object using a single, unbroken line of extruded filament. The resulting object has only one wall and zero infill, but it’s still plenty strong for an ornament. Despite its size, [Dave]’s giant ball uses only 220 grams of filament.

A video (also embedded below) shows the design in better detail. If you’d like to experiment, we’ve previously covered how PETG’s transparency is best preserved when 3D printing by using vase mode, slightly overextruding, and printing at a higher temperature to ensure solid bonding between each layer. Continue reading “3D Printing A Nifty Sphere Without Supports” →