When we think about sending an STL off on the Internet for processing, we usually want someone to print it for us or we want mesh repair. But [Chuck] found an interesting project on GitHub from [Andrew Sink] that will let you add a variable amount of twist to any STL and then return it to you for printing or whatever else you use STLs for. If you don’t get what we mean, check out the video below.

The site that does the work initially loads a little gnome figure if you are too lazy to upload your own model. That’s perfect, though, because the little guy is a good example of why you might want to twist a model. With just a little work, you can make the gnome look in one direction or even look behind him.

[Chuck] shows how to use the tool for artistic effect by twisting his standard cube logo. The result is something that looks like it would be difficult to create, but could hardly be easier. The tool lets you rotate the object, too, so you can get the twist effect in the right orientation for what you want to accomplish. A great little tool for making more artistic 3D prints without learning new software. If you want some fun, you can try the version that uses sound from your microphone to control the twist.

If you’d rather twist in CAD, we can help. If you really want artsy 3D printing, you probably need to learn Blender.

Hydraulics are incredibly versatile, but due to the pressures at which they operate, they are also rather expensive and not very DIY-friendly. This isn’t to say that you cannot take a fair shot at a halfway usable 3D-printed set of hydraulics, as [Indeterminate Design] demonstrates in a recent video. Although not 100% 3D-printed, it does give a good idea of how far you can push plastic-based additive manufacturing in this field.

Most interesting is the integration of the gear pump, 4-way selector valve, and relief valve into a single structure, which was printed with a resin printer (via the JLC3DP 3D print service). After bolting on the (also 3D printed) clear reservoir and assembling the rest of the structure including the MR63 ball bearings, relief spring valve, and pneumatic fittings it was ready to be tested. The (unloaded) gear pump could pump about 0.32 L/minute, demonstrating its basic functionality.

For the hydraulic cylinder, mostly non-3D printed parts were used, with a brass cylinder forming the main body. During these initial tests, plain water was used, followed by CHF11 hydraulic oil, with a pressure of about 1.3 bar (19 PSI) calculated afterward. This fairly low pressure is suspected to be caused by leaky seals (including the busted shaft seal), but as a basic proof of concept, it provides an interesting foundation for improvements.

Want a primer on hydraulics? We got you. MIT likes 3D printing with hydraulics, too (dead link, but the underlying paper link is still good).

Developing free and open source software can be a thankless experience. Most folks do it because it’s something they’re passionate about, with the only personal benefit being the knowledge that there are individuals out there who found your work useful enough to download and install. So imagine how you’d feel if it turns out somebody was playing around with the figures, and the steady growth in the number of installs you thought your software had turned out to be fake.

That’s what happened just a few days ago to OctoPrint developer [Gina Häußge]. Although there’s no question that her software for remotely controlling and monitoring 3D printers is immensely popular within the community, the fact remains that the numbers she’s been using to help quantify that popularity have been tampered with by an outside party. She’s pissed, and has every right to be.

[Gina] discovered this manipulation on June 26th after taking a look at the publicly available usage stats on data.octoprint.org. She noticed that an unusually high number of instances appeared to be running an old OctoPrint release, and upon closer inspection, realized what she was actually seeing was a stream of bogus data that was designed to trick the stat counter. Rolling back the data, she was able to find out this spam campaign has been going on since late 2022. Tens of thousands of the users she thought she’d gained over the last two years were in fact nothing more than garbage spit out by some bot. But why?

Here’s where it gets interesting. Looking at the data being reported by these fake OctoPrint instances, [Gina] could tell the vast majority of them claimed to be running a specific plugin: OctoEverywhere. The perpetrators were clever enough to sprinkle in a random collection of other popular plugins along with it, but this specific plugin was the one most of them had in common. Sure enough this pushed OctoEverywhere to the top of the charts, making it seem like it was the most popular plugin in the community repository.

So what do the developers of OctoEverywhere have to say for themselves? In a statement that [Gina] posted on the OctoPrint blog, they claim they were able to determine a member of the community had performed the stat manipulation of their own accord, but as of this writing are unwilling to release this individual’s identity. A similar statement now appears on the OctoEverywhere website.

On June 27th, Gina Häußge, the developer behind OctoPrint, informed us of an incident involving the OctoPrint usage stats. Gina had observed that the stats were being manipulated to boost OctoEverywhere’s rankings.

We took the report very seriously and quickly started an investigation. Using private community channels, we determined a community member was responsible for manipulating the OctoPrint stats. We had a private conversation with the individual, who didn’t realize the impact they were having but apologized and promised never to do it again.

From a journalistic perspective, it would be inappropriate for us to leap to any conclusions based on the currently available information. But we will say this…we’ve heard more convincing stories on a kindergarten playground. Even if we take the statement at face value, the fact that they were able to figure out who was doing this within 48 hours of being notified would seem to indicate this person wasn’t exactly a stranger to the team.

In any event, the bogus data has now been purged from the system, and the plugin popularity charts are once again showing accurate numbers. [Gina] also says some safeguards have been put into place to help prevent this sort of tampering from happening again. As for OctoEverywhere, it slid back to its rightful place as the 6th most popular plugin, a fact that frankly makes the whole thing even more infuriating — you’d think legitimately being in the top 10 would have been enough.

On Mastodon, [Gina] expressed her disappointment in being fooled into thinking OctoPrint was growing faster than it really was, which we certainly get. But even so, OctoPrint is a wildly popular piece of software that has become the cornerstone of a vibrant community. There’s no question that her work has had a incredible impact on the world of desktop 3D printing, and while this turn of events is frustrating, it will ultimately be little more than a footnote in what is sure to be a lasting legacy.

[Teaching Tech] got an interesting e-mail from [Johan] showing pictures of 3D prints with a dye-sublimated color image on the surface. Normally, we think of dye sublimation, we think of pressing color pictures onto fabric, especially T-shirts. But [Johan] uses a modified Epson inkjet printer and has amazing results, as you can see in the video below.

The printers use separate tanks for ink, which seems to be the key. If you already have an Espon “tank” printer, you are halfway there, but if you don’t have one, a cheap one will set you back less than $200 and maybe even less if you pick one up used.

You have to fill bottles with special dye, of course. You can also use the printer to make things like T-shirts. The idea is to print a dye transfer page and place it on the bed before you start printing. The sublimation dye is activated with heat, and, of course, you are shooting out hot plastic, so the image will transfer to the plastic.

[Teaching Tech] explains the best settings to make it all work. The results look great and we’re interested to try this ourselves. Transferring bed images is old hat, but this is something else. Beats liar’s color printing.

When you first unwrap a shiny new roll of filament for your FDM printer, it typically has a bag of silica gel inside. While great for keeping costs low on the manufacturing side, is silica gel the best solution to keep your filament dry at home?

Frustrated with the consumable nature and fussy handling of silica gel beads, [Build It Make It] sought a more permanent way to keep his filament dry. Already familiar with activated alumina beads, he crafted a desiccant cylinder that can be popped into the oven all at once instead of all that tedious mucking about with emptying and refilling plastic capsules.

A length of aluminum intake pipe, some high temperature epoxy, and aluminum mesh are all combined to make a simple, sealed cylinder. During the process, he found that using a syringe filled with the epoxy led to a much more precise application to the aluminum cylinder, so he recommends starting out that way if you make these for yourself.

We suspect something with a less permanent attachment at one end would let you periodically swap out the beads if you wanted to try this hack with the silica beads you already had. Perhaps some kind of threaded pipe fitting? If you want a more active dryer, try making one with a Peltier. If you want to know just how dry your filament is getting, you could also put in a sensor. You might also wonder, do you really need to dry filament at all?

Have you ever read about something and thought, “Gee whiz! Why did I never think about that?” That was my reaction to reading about a feature commonly associated with Klipper called adaptive bed leveling or adaptive mesh leveling. Too bad I don’t typically use Klipper, but it all worked out, and I’ll show you how it might work for you.

What Is It?

Once a luxury, most 3D printers now come with some kind of bed level sensor. The idea is that the printer can probe the bed to determine the shape of the build plate and then adjust the build plate accordingly. So if a particular spot on the bed is 0.5 mm too high, the nozzle can rise 0.5 mm when it is in that area. There are several techniques Marlin firmware uses, including what I usually use: UBL. Some people scan the bed once and hope it won’t change much. Others will do a time-consuming scan before each print.

However, adaptive bed leveling is a bit different. The idea is that the printer only probes the area where the part is going to print. If your print bed is 235 mm x 235 mm but your part is 50 mm square, you could just probe the points under the 50 mm square.

This does several things. For a given number of points, there is less motion, so it should be faster. Also, for the same number of points, you will have a much denser mesh and, thus, a better idea of what the bed is at any given point. You could even reduce the number of points based on the size of the part you are printing.

When you think about it, it is a dead simple idea. What’s not to love? For most print jobs, you’ll have less work for the printer, faster prints, and a denser mesh. But how do you do it?

How Do You Do It?

Can you make this work with your printer? Maybe. The trick is you need a way to tell your printer firmware to restrict the mesh area. You also need a way to have the slicer output a bounding box for the part, but that’s usually not hard. If you had to, you could even post process your Gcode and figure that out, but you probably won’t have to.

I

f you use linear or bilinear leveling, you are in business. That’s because the G29 command for bilinear accepts an L, R, F, and B parameter that lets you set the left, right, front, and back measurements of the probing grid. You can also set the number of probe points with H. Actually, H sets one side of the square, so if H=5, you will probe 25 points in the area.

However, I use UBL, and on one of my printers, I think I’m out of luck without changing something in the firmware. While there is a mesh inset setting, it is set when you build the firmware, so it won’t be practical to change it on the fly.

However, two of my printers are Ender 3 v2 Neo machines. By themselves, they use some odd variant of normal leveling, but I long ago flashed them with the excellent “professional” firmware by [mriscoc]. This is Marlin configured for these machines and — at least the version I use — has UBL set. But, there’s a catch.

The firmware has some custom Gcodes that start with C. C29 sets the mesh size and location very much like other versions. For some reason, it also sets the temperature. Here’s the documentation:

C29 Ln Rn Fn Bn Tn Nn Xn Ym : set probing mesh inset (Left, Right, Front, Back) in mm. T is the probing temperature (T0 doesn’t change the current bed temperature) and N is the density or amount of grid points NxN, it is posible to set a NxM density by using X and Y. In UBL use G29 S# to save to a mesh slot number #.

Try It!

Just as an experiment, I sent the following to the printer via a terminal:

C29 L100 R150 F100 B150 T0 N5

Nothing happened. But when I performed a G29 P1 to probe the bed, it obeyed the new restriction. All that was left was to make the slicer output the correct startup code. Of course, if you are using bilinear levelling, you’ll use G29 instead and have to change a few of the arguments.

Engage Start Up Sequence

Most slicers allow you to put placeholder variables in your Gcode scripts. You may have to look it up for your slicer. There are also plugins that can do the work, but you’d need to change their G29 to C29 (in my case). I mostly use SuperSlicer, which is forked from PrusaSlicer, which is forked from Slic3r.

Here’s part of my startup code:

G28 ; home all
C29 L{first_layer_print_min[0]} R{min(190,first_layer_print_max[0])} F{first_layer_print_min[1]} B{min(180,first_layer_print_max[1])} T0 N5
G29 P1  ; probe
G29 A   ; activate (may not be needed?)
G29 F2  ; Fade height 2mm (or whatever you want)

That’s it. If you have a line that purges your nozzle, you might want to correct it using similar logic or just add a few skirt loops in the slicer and forget about it. Note that I probe 25 points, which might be a bit much for a small part. It would be nice to write a script to detect how big a part is and adjust things. Note that Prusa has enough power to do this totally in the start code, but it would be different in Slic3r or Cura. If you look around, there are a few different examples of doing this for both slicers and various firmware that you will — no doubt — have to adapt to your circumstances.

I need to crack into the firmware for my other printer to see if a similar C command is feasible to add. But that’s for another day, especially since the C29 command is provided as object code only, so I’ll have to start from scratch. Luckily, I’m used to building (and rebuilding) Marlin for all the machines, especially that one, since it is a custom blend of many parts. I may switch out to bilinear leveling. Or, I could break down and go to Klipper, I suppose.

We want to try fast scanning next. Of course, things are simple if you tram your flat bed once and forget it. That is until something changes.

It seems to make sense. If you have a 3D printer, you might wish you could just scan some kind of part and print it — sort of like a 3D photocopier. Every time we think about this, though, we watch a few videos and are instantly disappointed by the results, especially with cheap scanners. If you go the hardware route, even cheap is relative. However, you can — in theory — put an app on your phone to do the scanning. Some of the apps are free, and some have varying costs, but, again, it seems like a lot of work for an often poor result. So we were very interested in the video from [My 3D Print Lab] where he uses his phone and quite a few different apps and objectively compares them.

Unsurprisingly, one of the most expensive packages that required a monthly or annual subscription created an excellent scan. He didn’t print from it, though, because it would not let you download any models without a fee. The subject part was an ornate chess piece, and the program seems to have captured it nicely. He removed the background and turntable he was using with no problems.

Other apps didn’t fare as well, either missing some of the parts or failing to omit background elements. You may have to do some post-processing. Some of the other expensive options have free trials or other limits, but you can at least try them for free. One of the free trials let you do three free scans, but each scan took about 8 hours to process.

There are some free options, too, and while they aren’t great, most of the paid ones aren’t very good either. The apps tested are: Widar, Polycam, xOne, RealityScan, MagiScan, Qlone, Kiri Engine, and MakerWorld AI Scanner. Not all of these would provide a free download, but for the ones that did, he tried to print the resulting model from each. Qlone didn’t work on Android, so it didn’t get tested either.

Of the phone apps, Kiri Engine looks like the best. However, he also shows MakerWorld AI Scanner, a Web app that converts videos. It had a few minor issues, but it did a great job and looks like something that might be fun to try, especially since it is free. They also have a tool on that same website that has a limited number of uses per month that claims it can create a 3D model from a single photograph (and not just an extrusion of the flat image). There’s some science behind that.

If you just want the results, you can skip to about 14:50 to learn the reasoning behind the top three picks in each evaluation category. We know sometimes it is just as easy to design a part as scan it. We’ve used one of those cheap turntable scanners before, but they have gotten somewhat better recently.

[Joel] picked up a wireless mouse kit. The idea is you get some 3D printing files and hardware. You can print the shell or make modifications to it. You can even design your own shell from scratch. But [Joel] took a different approach. He created a case with transparent resin. You can see the impressive result in the video below.

While the idea of buying the mouse as a kit simplifies things, we would be more inclined to just gut a mouse and design a new case for it if we were so inclined. We were more impressed with the results with the transparent resin.

Having transparent 3D printing capabilities opens up some artistic possibilities, like the benchy inside a glass bottle that makes a guest appearance on the video. The only limitation we can see is that your entire print has to be clear unless you do some hacky workarounds. For example, it would have been cool to have a mouse that was only transparent through a window. Short of painting the finished product, this would be tough to do with modern printers.

Even though you can get transparent filament, FDM printers have to work hard to get even sort of transparent. Even then, the results can be impressive, but nothing like what [Joel] is doing in resin, of course.

[3DJake] likes putting textures on 3D prints using things like patterned build plates and fuzzy skin. However, both of those techniques have limitations. The build plate only lets you texture the bottom, and the fuzzy skin texture isn’t easy to control. So he shows how to use Blender to create specific textures to produce things like wood-like or leather-like surfaces, for example. You can see how it works in the video below.

As [Jake] points out, you might be able to use other artistic programs to do this, but the kind of things we use like FreeCAD of Fusion360 aren’t going to cut it.

He uses a bag with a leather texture as an example. The resulting model is too detailed and contains around 1.4 million triangles. Your printer isn’t that detailed, and your slicer will probably choke on a model with that many triangles. Decimating the model makes it more manageable.

The resulting bags, when printed using TPU and painted, hardly look like 3D prints. Well, other than the strap, perhaps. The textures were just pulled from the Internet, so there are, potentially, many to choose from as long as they are seamless.

One interesting build plate texture is a diffraction grating. You can also add special textures manually. Textures are good at hiding layer lines, even just the fuzzy skin textures you find in many slicers.

We touched on the open source SLS4All DIY SLS 3D printer a year or two ago when the project was in the early stages. Finally, version one is complete, with a parts kit ready to ship and all design data ready for download if a DIY build or derivative is your style. As some already mentioned, this is not going to be cheap: with the full parts kit running at an eye-watering $7K before tax. But it’s possible to build or source almost all of it a bit at a time for those on a budget.

It’s important to note that to access the detailed information, you’ll need to create an account, which is a bit inconvenient for an open source design. However, all the essential components seem to be available, so it’s forgivable. In terms of electronics, there are two custom PCBs: the GATE1 (GAlvo and Temperature Control) and the ZERO1 (Zero-crossing dimming) controller. Other than that, all the electronics seem to be standard off-the-shelf components. Both of these PCBs are designed using EasyEDA.

Unfortunately we couldn’t find access to the PCB Gerbers, nor does there appear to be a link to their respective EasyEDA projects, just the reference schematics. This is a bit of a drawback, but it’s something that could easily be reproduced with enough motivation. Control is courtesy of a Radxa Rock Pi, as there were ‘problems’ with a Raspberry Pi. This is paired with a 7-inch touchscreen to complete the UI. This is running a highly modified version of the Klipper together with their own control software, which is still undergoing testing before release.

The laser head is built around a 10 W 450 nm laser module from China and a high-end galvanometer set. Two 200 W halogen tube heaters heat the print bed, and 200 W silicone heating pads heat both the powder bed and the print bed.

The upper and lower frames are basic boxes made from 2020 profile aluminium extrusions, with aluminium sheets for the panels. There are no big surprises here. As expected, numerous custom-made aluminium parts are involved, and this is where most of the cost lies. This might be a significant challenge for those who don’t have access to a CNC milling machine. The mechanics can be viewed in-browser via Fusion 360 Live or downloaded as a STEP model for later import.

We last checked in on this project back in 2022, and we’re glad to see it finally cross the finish line. Is this the first open source SLS printer? Of course not! But we’re always glad to see more options out there.

While 3D printers have evolved over the past two decades from novelties to powerful prototyping tools, the amount of support systems have advanced tremendously as well. From rudimentary software that required extensive manual input and offered limited design capabilities, there’s now user-friendly interfaces with more features than you could shake a stick at. Hardware support has become refined as well with plenty of options including lighting, ventilation, filament recycling, and tool changers. It’s possible to automate some of these subsystems as well like [Caelestis Workshop] has done with this relay control box.

This build specifically focuses on automating or remotely controlling the power, enclosure lighting, and the ventilation system of [Caelestis Workshop]’s 3D printer but was specifically designed to be scalable and support adding other features quickly. A large power supply is housed inside of a 3D printed enclosure along with a Raspberry Pi. The Pi controls four relays which are used to control these various pieces hardware along with the 3D printer. That’s not the only thing the Pi is responsible for, though. It’s also configured to run Octoprint, a piece of open-source software that adds web interfaces for 3D printers and allows their operation to be monitored and controlled remotely too.

With this setup properly configured, [Caelestis Workshop] can access their printer from essentially any PC, monitor their prints, and ensure that ventilation is running. Streamlining the print process is key to reducing the frustration of any 3D printer setup, and this build will go a long way to achieving a more stress-free environment. In case you missed it, we recently hosed a FLOSS Weekly episode talking about Octoprint itself which is worth a listen especially if you haven’t tried this piece of software out yet.

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.

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.

[Thanks to Keith Olson for the tip!]

Imagine you want to iterate on a shock-absorbing structure design in plastic. You might design something in CAD, print it, then test it on a rig. You’ll then note down your measurements, and repeat the process again. But what if a robot could do all that instead, and do it for years on end? That’s precisely what’s been going on at Boston University.

Inside the College of Engineering, a robotic system has been working to optimize a shape to better absorb energy. The system first 3D prints a shape, and stores a record of its shape and size. The shape is then crushed with a small press while the system measures how much energy it took to compress. The crushed object is then discarded, and the robot iterates a new design and starts again.

The experiment has been going on for three years continuously at this point. The MAMA BEAR robot has tested over 25,000 3D prints, which now fill dozens of boxes. It’s not frivolous, either. According to engineer Keith Brown, the former record for a energy-absorbing structure was 71% efficiency. The robot developed a structure with 75% efficiency in January 2023, according to his research paper.

Who needs humans when the robots are doing the science on their own? Video after the break.

[Thanks to Frans for the tip!]

Accessibility devices are a wonder of modern technology, allowing people with various needs to interact more easily with the world. From prosthetics to devices to augment or aid someone’s vision or hearing, devices like these can open up many more opportunities than would otherwise exist. A major problem with a wide array of these tools is that they can cost a fortune. [3D Printy] hoped to bring the cost down for Braille trainers which can often cost around $1000.

Braille trainers consist of a set of characters, each with six pins or buttons that can be depressed to form the various symbols used in the Braille system. [3D Printy]’s version originally included six buttons, each with a set of springs, that would be able to pop up and down. After some work and real-world use, though, he found that his device was too cumbersome to be effective and redesigned the entire mechanism around flexible TPU filament, allowing him to ditch the springs in favor of indentations and buttons that snap into place without a dedicated spring mechanism.

The new design is modular, allowing many units to be connected to form longer trainers than just a single character. He’s also released his design under the Creative Commons public domain license, allowing anyone to make and distribute these tools as they see fit. The design also achieves his goal of dramatically reducing the price of these tools to essentially just the cost of filament, provided you have access to a 3D printer of some sort. If you need to translate some Braille writing and don’t want to take the time to learn this system, take a look at this robotic Braille reader instead.

Thanks to [George] for the tip!

As desktop 3D printers have inched towards something resembling the mainstream, manufacturers have upped their game across the board. Even the quality of filament that you can get today is far better than what was on the market in the olden days, back when a printer made out of laser-cut birch wasn’t an uncommon sight at the local makerspace. Now, even the cheap rolls are wound fairly well and are of a consistent diameter. For most folks, you just need to pick a well-reviewed brand, buy a roll, and get printing.

But as with everything else, there are exceptions. Some people are producing their own filaments, or want to make sure their extrusion rate is perfectly calibrated. For those that need the capability, the WInFiDEL from [Sasa Karanovic] can detect filament diameter in real-time while keeping the cost and complexity as low as possible. Even better, with both the hardware and software released as open source, it makes an excellent starting point for further development and customization.

In fact, the WInFiDEL itself was developed from the earlier InFiDEL sensor designed by [Thomas Sanladerer]. This new version uses the same basic mechanism: a pair of bearings, with one fixed in position and the other attached to an arm with a magnet on the end. As the filament passes between the bearings, the arm raises and lowers the magnet, which is detected by a linear Hall-effect sensor. The resulting raw deflection data, once properly calibrated, provides a highly accurate readout of the filament diameter as it passes through the sensor and into the extruder.

What’s changed is how the sensor is utilized. [Thomas] imagined the original sensor as being connected directly to the 3D printer’s motherboard, with its data being used to modify the extrusion rate during printing. In other words, it wasn’t really designed for humans to use. For the WInFiDEL, [Sasa] dropped the anemic ATTiny85 and replaced it with an ESP32 that can connect to your WiFi network and offer up a slick web interface, complete with a easy to use calibration tool and a rolling graph that plots out the data as it comes in. There’s also an API that allows you to hit the sensor with a web request to get current diameter and calibration data should you want to virtually connect it up to something like OctoPrint.

Most of us don’t need the WInFiDEL. But looking at the exceptional hardware and software of this project, we sure as hell want one anyway. Of course, we’d expect no less from [Sasa]. Whether its his OS-agnostic fan controller or ESP32 powered camera slider, his creations always exhibit a sort of simplistic elegance that we’re big fans of.

These days, you can get a fully remote-control helicopter that you can fly around your house for about $30. Maybe less. Back in the day, kids had to make do with far simpler toys, like spinning discs that just flew up in the air. [JBV Creative] has built a toy just like that with his 3D printer. It may be simple, but it also looks pretty darn fun.

The design is straightforward. It uses a power drill to spin up a geartrain, which in turn drives a small disc propeller. Spin the propeller fast enough and it’ll launch high into the air. The geartrain mounts to the drill via the chuck, and it interfaces with the propeller with a simple toothed coupler. Alternatively, there’s also a hand-cranked version if you don’t have a power drill to hand.

Launching is easy. First, the drill spins the propeller up to speed. Then, when the drill’s trigger is released, it slows down, and the propeller spins free of the toothed coupler, with the lift it generates carrying it into the sky.

Files are available online for those interested. We could imagine this toy could make the basis for a great design competition. Students could compete to optimise the design with more effective gear ratios or better airfoils. We’ve seen similar designs before, too. Video after the break.

[Stefan] from CNC Kitchen explored an unusual approach to a multi-material print by making custom PLA filament with a TPU core to make it super-tough. TPU is a flexible filament whereas PLA is hard almost to the point of being brittle. The combo results in a filament with some unusual properties, inviting some thoughts about what else is possible.

[Stefan]’s video covers a few different filament experiments, but if you’d like to see the TPU-PLA composite you can skip ahead to 18:15. He first creates the composite filament by printing an oversized version on a 3D printer, then re-forming it by running it through a Recreator to resize it down to 1.75 mm.

We have seen this technique of printing custom filaments before, which is useful to create DIY multi-color filaments in small quantities right on a 3D printer’s print bed with no special equipment required. This is an effective method but results in filament with a hexagonal profile, which works but isn’t really ideal. By printing his custom composite at 4 mm diameter then resizing the filament down to 1.75 mm, [Stefan] was able to improve overall printability.

That being said, TPU and PLA have very different characteristics and don’t like to adhere to one another so the process was pretty fiddly. TPU-cored PLA might be troublesome and uncooperative to make, but it can be done with some patience and fairly simple equipment.

Despite the difficulties, test prints were pretty interesting. PLA toughness was roughly doubled and under magnification one can see a lattice of TPU strands throughout the prints which are unlike anything else. Check it out in the video, embedded below.

A common way to visualize that a 3D printer’s extruder motor — which feeds the filament into the hot end — is moving is to attach a small indicator to the exposed end of the motor’s shaft. As the shaft turns, so does the attached indicator.

Small movements of the motor are therefore turned into larger movements of something else. So far, so simple. But what about visualizing very small extrusions, such as those tiny ones made during ironing?

[Jack]’s solution is a Vernier indicator for the extruder. Even the smallest movements of the extruder motor’s shaft are made clearly visible by such a device, as shown in the header image above. Vernier scales are more commonly found on measurement tools, and the concept is somewhat loosely borrowed here.

The usual way these lightweight indicators are attached is with a small magnet, and you can read all about them and see examples here.

This new design is basically the same, it simply has a background in a contrasting color added into the mix. [Jack]’s design is intended for the Bambu A1 printer, but the idea can be easily adapted. Give it a look if you find yourself yearning for a bit more visibility in your extruder movements.