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.

[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.

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.

[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.

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!]

So often, we see 3D printers used to create some nifty little tool for a tricky little job. Maybe it’s to lock cams together for a timing belt change, or to work as a jig for soldering some complex device. However, some hacks are even simpler than that. [maker_guy] realized that eating nuggets in the car could be easier than ever with a little printed adapter.

The print is simple. It’s a round caddy for the nugget sauces given out by Chick-fil-A restaurants. Why round? Because it lets the nugget sauce sit neatly in your car’s cupholder at an accessible height. Put the sauce tub in the adapter, peel it open, and you can dip to your heart’s content.

No more delicately balancing Zesty Buffalo by the gearstick while you try and chow down. Nor will your seat covers be tainted with Honey Mustard!

“Not a hack!” you scream. “It’s frivolous nonsense!” To that I say, are you a nugget eater or not? I myself partake, and I can absolutely see the value in this. You see, us journalists work hard. We’re often stuck eating substandard food in our cars on the way from one thing to another, like so many others in busy professions. If a smart little 3D-printed adapter can make mealtime easier and save some mess, I’m calling that a win.

You should never be afraid to use your creativity to make tools to improve your life. Parts are on Thingiverse if you need to print your own. Mod it to suit McDonald’s product if you need. Heck, print in black and it’d look like a stock part of the car!

You don’t have to like this simple adapter, but you can’t deny its utility! Share your own nifty little adapter ideas in the comments.