A 3D printer hotend with four filament leads in positioned on an arm above a hole in a glass plate. Wires lead from a carbon fiber frame under the glass to four stepper motors with pulleys.

The Final Steps To A Sub-Minute Benchy

May 30, 2026 by Aaron Beckendorf No comments

In 2024, [Jan Roetz] decided to see whether he could 3D print a Benchy – the boat-shaped benchmarking tool used in 3D printer calibration – in less than one minute. Two years later, after experiments with air bearing print beds, dry ice cooling, multi-filament hotends, and more, he’s finally broken the one-minute mark.

There are three primary factors limiting the speed of the printer: the extrusion flow rate, the cooling rate for extruded plastic, and the motion system itself. The printer’s hotend combines four strands of filament in one hotend and can extrude about 400 cubic millimeters of plastic per second. For cooling, an air duct around the nozzle could deliver about 400 liters of air per minute, which left the motion system as the only bottleneck.

The original print bed was on top of an air bearing on a granite base, and its motion could be controlled by cords connected to stepper motors. This whole system had very low friction, but its inertia was too high. [Jan] therefore replaced the build plate with a lighter carbon-fiber frame. This had no air bearing, but it slid between the base granite slab and a glass plate above it, which had an opening above the portion used as a build plate. Even the metal pulleys used on the stepper motors had too much inertia, so [Jan] replaced them with smaller, semi-circular plastic pulleys.

The first test was a sub-60-second dry run to make sure nothing would break. This revealed the need for cable guides to keep them from whipping around (not surprising when they were pulling the bed at an acceleration of 225 G). Finally, [Jan] was able to successfully print several successive 59-second Benchies. The prints weren’t photogenic, but they were mechanically sound and dimensionally correct. [Jan] could have gone even faster, but this degraded the print quality too much.

It’s quite an accomplishment, and an impressive conclusion to a major project; we covered the beginning of the project back when [Jan] was going for parallelization rather than speed. The final print didn’t use it, but he also experimented with dynamic temperature control.

Continue reading “The Final Steps To A Sub-Minute Benchy” →

Testing Various Ways To Waterproof FDM Printed Parts

May 30, 2026 by Maya Posch 8 Comments

Along with layer lines, FDM printers are notorious for being neither air- nor water-tight due to the countless very small gaps between the layers. This is very unfortunate if you are trying to FDM print something that should keep water either inside or outside. Although a variety of potential solutions exist, it’s hard to easily compare them. Correspondingly [Half-Baked-Research] decided that the best approach here was to just try everything and pit them against each other.

These solutions include various coatings either in- or outside the part, as well as the foam solution that he tried previously joined by a number of community-suggested alternatives that should not get waterlogged. To properly test them, the water pressure at a depth of about 10 meters would be good enough, but rather than find a really deep swimming pool or try his luck at nearby bodies of water, compressed air was used to ramp up the pressure of a what is basically a big bucket of water.

For the pressure chamber a Vevor vacuum chamber was modified to contain the 1 bar (103 kPa) of pressure, which was a fair bit of work and required a CNCed metal top plate. Among the printed and treated samples were also a couple of wild cards: a PETG cube with a TPU printed cover, a PU molded part and PETG with thicker walls.

Along with the long soak, percussive testing was also performed to see how it’d affect the water intrusion resistance. After all that, there were three winners: internal epoxy coating and two types of internal PU coating, though epoxy held up the best after repeated abuse. PU rubber also got a thumbs-up if you don’t need as high a pressure resistance but are more concerned with resisting physical abuse.

Continue reading “Testing Various Ways To Waterproof FDM Printed Parts” →

A person is standing in front of an acrylic enclosure, lowering a door on the enclosure. The enclosure contains the space between two sets of cabinets, and has three doors on the front. Inside the enclosure is an air filter and a washing station.

A Fume-Control Cabinet For Resin 3D Printing

May 29, 2026 by Aaron Beckendorf 6 Comments

For a certain kind of intricate, highly-detailed manufacturing, there’s really no substitute for a resin 3D printer, and it’s therefore unfortunate that they require so many poisonous chemicals. The resin itself usually contains irritating acrylates and methacrylates, it can emit a wide spectrum of volatile organic compounds (VOCs) during printing, and even the isopropyl alcohol used in cleaning is moderately toxic. [Allie Katz] accordingly built this fume-control enclosure for resin printing and other ventilation-critical processes.

The biggest constraint was space: [Allie]’s workspace had a fairly limited volume available, and the enclosure needed to hold an SLA printer, an isopropyl alcohol washing station, a UV curing chamber, and miscellaneous supplies. Most of the enclosure was made out of IKEA cabinets, using some large cabinets at the base to hold the printer and curing station, a countertop over these to hold the washing station, and more cabinets above to hold supplies. An MDF backing panel and acrylic side panels enclose the workspace between the cabinets. There was no safe way to exhaust fumes, so the enclosure recycles its air: a fan pulls air in through an activated-carbon filter mounted above the work area and into the plenum behind the chamber, from which it passes through the printer’s cabinet back into the workspace enclosure. Panel filters surround the carbon filter to catch particulate matter.

The enclosure uses four ESP32-based boards for automation: one uses a touchscreen to display data, and three are paired with BME680 sensors, primarily to report VOC concentrations. One, which also has a particulate matter sensor, senses air quality in the main chamber and plenum, one monitors air quality in the rest of the shop, and the third detects clogging from within the filter enclosure. The first real test of the chamber was to 3D print and paint some handles for the cabinets. It worked as expected, detecting the increased VOCs and ramping up the fan to keep them in check.

We’ve seen a ventilated printer enclosure before, that time for an FDM printer. Although their hazards are less blatant, they too can produce dangerous fumes, which could possibly be carcinogenic.

Thanks to [Keith Olson] for the tip!

Designing A Printable Cyclone Dust Separator For 99.95% Efficiency

May 24, 2026 by Maya Posch 15 Comments

Filtering sawdust out of an airflow is easy until you try to do it with cyclone separation, but the obvious appeal here is of course not spending a fortune on filters. Over the years we have thus seen a lot of DIY takes on this concept alongside commercial offerings. Recently [Ruud] of the [Capturing Dust] YouTube channel gave it a fresh shake with a claimed 99.95% filtering efficiency that outperforms a commercial solution.

As a starting point the commercial and very succinctly named Oneida Air Super Dust Deputy Cyclone Separator was used, which retails for about $179 and claims a 99.9% filtrating rate of fine dust and debris. Based on its design a 3D model was created and printed with an FDM printer.

Initially only about a 98% rate was measured, but after some investigation this appeared to be due to the incoming and exciting airflows interfering. One tweak later to add some separation between the flows and a lot of testing of different configurations a final design was settled on that would seem to be rather quite efficient compared to the commercial option.

Continue reading “Designing A Printable Cyclone Dust Separator For 99.95% Efficiency” →

Putting Version 7.1 Of The Direct Granules FDM Extruder Through Its Paces

May 23, 2026 by Maya Posch 11 Comments

Whether you’re using granules or filament, FDM printing relies heavily on a consistent flowrate of the extruder. This is also the challenge with [HomoFaciens]’s direct granule extruder. Version 7.1 here refines some parameters before being put through a number of printing tests to see how close it comes to something you’d want to use for production.

There’s also an accompanying blog post, on which the project files can be found for those who are playing along at home.

A big part of this V7.1 change was to simplify the design for manufacturing, removing the brass insert of V7.0, instead requiring some manual labor using a drill bit and a hand reamer to get the inside of the extruder tube just right.

The section with the heating element was also extended, though this didn’t have as much of an effect as expected. During testing the overall results were actually pretty good, with the extruder able to keep up with bridging tests while the feared air bubbles from air intruding into the tube remained absent.

On the Prusa Mk4 FDM printer, there are some definite limitations on testing features like input shaping resulting in wavy patterns in some rest prints, but for upcoming tests a different FDM printer will be used which should more clearly show the potential of this extruder design.

Continue reading “Putting Version 7.1 Of The Direct Granules FDM Extruder Through Its Paces” →

Investigating The Health Impacts Of UFPs And VOCs From FDM Printers

May 20, 2026 by Maya Posch 22 Comments

FDM 3D printing is fairly messy on a molecular scale, with the filament being heated up to temperatures high enough to melt it, which produces ultra-fine particles (UFPs) and volatile organic compounds (VOCs) in addition to the new plastic item on the build plate. Recently [Simon Pow] got somewhat worried about this pollution considering that he spends a considerable amount of time in the same room as FDM printers, sharing air.

While there is a lot of context within the topic, it’s notable that even ‘low risk’ PLA already emits formaldehyde, a group 1 carcinogen. Studies like this 2022 one by [Taehun Kim] et al. on formaldehyde, PM10 and PM2.5 show that common filaments like PLA, ABS and TPU score pretty bad here, even compared to the often maligned resin printing, also in the study. Having good ventilation in a room helps a lot, but it doesn’t reduce the levels to zero.

As noted by [Simon], PETG is much better in the VOC area, while TPU emits siloxanes, some of which are dangerous but most are considered harmless. Once you hit nylon (e.g. PA6), you’re adding caprolactam, which is mildly toxic but mostly just an irritant. Where things get serious is with ABS and ASA, when you add styrene to the mix. This substance is very dangerous, being toxic, mutagenic and possibly carcinogenic, but on the plus side it smells kind of sweet.

Polycarbonate (PC) emits BPA, with its worrying long-term health implications, while carbon fibers in particular can have asbestos-like long-term effects, as we covered previously. Definitely wear PPE while doing things like sanding CF parts and safely dispose of any debris.

Of course, you can do something about this problem, such as having an enclosure around the printer, with HEPA filtration and activated carbon, potentially exhausting into the outside air. The options here are covered in the video, including a BentoBox filter. For [Simon] the biggest improvement – as measured by a whole room sensor – came from a big fan in the window, while the default activated carbon filter in the Bambu Lab printer did effectively nothing.

The problem here is mostly one of long-term exposure, so even basic precautions like filtration and ventilation can already make all the difference. Ideally you’d not have the printer in the same room as where you work, of course, but adding a good filtration setup doesn’t have to be expensive or hard.

Continue reading “Investigating The Health Impacts Of UFPs And VOCs From FDM Printers” →

A DIY 3D Printing Filament Dryer

May 20, 2026 by Maya Posch 23 Comments

In a recent video [Saša Karanović] revisits the DIY filament dryer that he gave a shot a couple of years ago. Back then he reused an existing filament dryer, adding a custom controller and such to improve its performance.

This technically-not-fully-DIY dryer got some feedback since then, and thus the V2 version is an example of how to better DIY such a dryer, including a custom PCB and a GitHub project for all the details.

Those who just want to dive into the documentation for assembly and the BOM can look at the available documentation. At its core the whole assembly consists of some kind of container like the shown 5L food storage type, along with an SHT30 temperature and humidity sensor and 100 K NTC temperature sensor. These connect to the controller board which then switches on or off the 12 V polyimide resistive heater.

One thing that could be improved here is that the saturated warm air has nowhere to go. This is a common issue with filament dryers and why it’s recommended with even commercial filament dryers like the common Sunlu types to leave them slightly ajar so that the moist air can be replaced with cooler air that can much more readily absorb moisture.

Continue reading “A DIY 3D Printing Filament Dryer” →