Origami-Inspired, Self-locking Structures With 3D Printing

December 13, 2024 by Donald Papp 1 Comment

Researchers recently shared details on creating foldable, self-locking structures by using multi-material 3D printing. These origami-inspired designs can transition between flat and three-dimensional forms, locking into place without needing external support or fasteners.

The 3D structure of origami-inspired designs comes from mountain and valley fold lines in a flat material. Origami designs classically assume a material of zero thickness. Paper is fine, but as the material gets thicker things get less cooperative. This technique helps avoid such problems.

An example of a load-bearing thick-film structure.

The research focuses on creating so-called “thick-panel origami” that wraps rigid panels in a softer, flexible material like TPU. This creates a soft hinge point between panels that has some compliance and elasticity, shifting the mechanics of the folds away from the panels themselves. These hinge areas can also be biased in different ways, depending on how they are made. For example, putting the material further to one side or the other will mechanically bias that hinge to fold into either a mountain, or a valley.

Thick-panel origami made in this way paves the way towards self-locking structures. The research paper describes several different load-bearing designs made by folding sheets and adding small rigid pieces (which are themselves 3D printed) to act as latches or stoppers. There are plenty of examples, so give them a peek and see if you get any ideas.

We recently saw a breakdown of what does (and doesn’t) stick to what when it comes to 3D printing, which seems worth keeping in mind if one wishes to do some of their own thick-panel experiments. Being able to produce a multi-material object as a single piece highlights the potential for 3D printing to create complex and functional structures that don’t need separate assembly. Especially since printing a flat structure that can transform into a 3D shape is significantly more efficient than printing the finished 3D shape.

Printing In Multi-material? Use These Filament Combos

December 7, 2024 by Donald Papp 15 Comments

If one has a multi-material printer there are more options than simply printing in different colors of the same filament. [Thomas Sanladerer] explores combinations of different filaments in a fantastic article that covers not just which materials make good removable support interfaces, but also which ones stick to each other well enough together to make a multi-material print feasible. He tested an array of PLA, PETG, ASA, ABS, and Flex filaments with each in both top (printed object) and bottom (support) roles.

A zero-clearance support where the object prints directly on the support structure can result in a very clean bottom surface. But only if the support can be removed easily.

People had already discovered that PETG and PLA make pretty good support for each other. [Thomas] expands on this to demonstrate that PLA doesn’t really stick very well to anything but itself, and PETG by contrast sticks really well to just about anything other than PLA.

One mild surprise was that flexible filament conforms very well to PLA, but doesn’t truly stick to it. Flex can be peeled away from PLA without too much trouble, leaving a very nice finish. That means using flex filament as a zero-clearance support interface — that is to say, the layer between the support structure and the PLA print — seems like it has potential.

Flex and PETG by contrast pretty much permanently weld themselves together, which means that making something like a box out of PETG with a little living hinge section out of flex would be doable without adhesives or fasteners. Ditto for giving a PETG object a grippy base. [Thomas] notes that flexible filaments all have different formulations, but broadly speaking they behave similarly enough in terms of what they stick to.

[Thomas] leaves us with some tips that are worth keeping in mind when it comes to supported models. One is that supports can leave tiny bits of material on the model, so try to use same or similar colors for both support and model so there’s no visual blemish. Another tip is that PLA softens slightly in hot water, so if PLA supports are clinging stubbornly to a model printed in a higher-temperature material like PETG or ABS/ASA, use some hot water to make the job a little easier. The PLA will soften first, giving you an edge. Give the video below a watch to see for yourself how the combinations act.

Continue reading “Printing In Multi-material? Use These Filament Combos” →

Make Multi-Material Resin Prints With A Syringe (And A Bit Of Patience)

August 22, 2022 by Donald Papp 15 Comments

Resin printing is a fantastic way to create parts, but multi-material printing isn’t really a possibility with resin. That is, unless you use [Cameron Coward]’s method for creating multi-material resin prints.

[Cameron]’s idea relies on the fact that handling and curing UV resin can easily be done outside of the printer itself. First, one prints what we’ll call the primary object. This object has empty spaces representing the secondary object. Once the primary object is printed and finished, these voids are carefully filled with a different resin, then cured with UV light. The end result is a single multi-material object that is, effectively, made from two different resins.

Continue reading “Make Multi-Material Resin Prints With A Syringe (And A Bit Of Patience)” →

Prusa XL Goes Big, But That’s Only Half The Story

November 29, 2021 by Tom Nardi 44 Comments

For a few years now it’s been an open secret that Prusa Research was working on a larger printer named, imaginatively enough, the Prusa XL. Positioned at the opposite end of their product spectrum from the wildly popular Prusa Mini, this upper-tier machine would be for serious hobbyists or small companies that need to print single-part objects that were too large for their flagship i3 MK3S+ printer. Unfortunately, the global COVID-19 pandemic made it difficult for the Czech company to focus on bringing a new product to market, to the point that some had begun to wonder if we’d ever see this mythical machine.

But now, finally, the wait is over. Or perhaps, it’s just beginning. That’s because while Prusa Research has officially announced their new XL model and opened preorders for the $1,999+ USD printer, it’s not expected to ship until at least the second quarter of 2022. That’s already a pretty substantial lead time, but given Prusa’s track record when it comes to product launches, we wouldn’t be surprised if early adopters don’t start seeing their machines until this time next year.

So what do you get for your money? Well, not an over-sized Prusa i3, that’s for sure. While many had speculated the XL would simply be a larger version of the company’s popular open source printer with a few modern niceties like a 32-bit control board sprinkled in, the reality is something else entirely. While the high purchase price and ponderous dimensions of the new machine might make it a tough sell for many in the hacker and maker communities, there’s little question that the technical improvements and innovations built into the Prusa XL provide a glimpse of the future for the desktop 3D printer market as a whole.

Continue reading “Prusa XL Goes Big, But That’s Only Half The Story” →

Enraged Rabbit Project Is A Filament Cocktail Special

October 4, 2021 by Sonya Vasquez 18 Comments

As long as 3D printers have been around, it seems as though many of us have dreamed about nozzle-sharing solutions for multicolor 3D prints. Just because Prusa’s MMU has had the spotlight for some time doesn’t mean that there’s no space to design something original. If you’re craving something new to feast your eyes upon, look no further than the EnragedRabbitProject by [EtteGit]. Built for Voron 3D printers, it’s a scalable filament changing solution designed from the ground up that expands to accommodate up to 9 filaments.

EnragedRabbitProject is broken into four main components. First comes the Enraged Rabbit Carrot Feeder (ERCF), the system that handles filament selection, retraction, and loading. Next, comes the Carrot Patch (ERCP), a spool holder/buffer combo that’s needed per spool. For those unfamiliar with filament changers, unspooling filament is easy, but rewinding it back onto the spool is hard. And since the nozzle will retract a significant length of filament when it switches between filaments, it’s important to manage all this extra loose filament to prevent tangles. A filament buffer is the solution; it’s a clever mechanical addition to the spool holder that will manage the extra filament that gets unwound during these filament changes. Beyond these two systems is the King’s Seat (ERKS) a Voron-2 setup that purges extra filament into beads instead of purge blocks, and finally, the filament sensor, which detects filament presence for filament changes.

It’s sometimes hard to appreciate the reliability of these sorts of CNC systems. On that note, keep in mind that the prints on the project’s landing page are the results of hundreds if not thousands of filament swaps — truly an astonishing feat. Beyond reliability is the project’s presentation. [EtteGit] has kindly posted STEP and STL files for all mechanical components, the Klipper configuration files, and a bill-of-materials that will scale according to the number of filaments you’re installing.

We’re thrilled to see folks continue to innovate on the concept of what it means to be a multi-color or multi-material 3D printer. For other takes on multi-filament setups, have a look at [Paul Paukstelis’] microscope-inspired head changer, and [MihaiDesigns’] removable tool head concept.

Continue reading “Enraged Rabbit Project Is A Filament Cocktail Special” →

Dial In Your Multi-Headed 3D Printer With 2020 Machine Vision

June 14, 2020 by Sonya Vasquez 7 Comments

Most folks that have been poking around at multi-tool 3D printing know that lining up nozzles can be a gnarly, but necessary pain point. Existing methods either have us measure offsets with a vernier scale or with a series of pictures taken with an upwards-facing camera. And this step is not to be ignored! Any mismatch between nozzles, and your multicolor prints end up looking like Scotty really screwed up those sliders on that transporter beam console. Fear not, however! [Danal] took this problem as an opportunity to write something that’s completely automated and brought to you by some machine vision.

Dubbed TAMV, for Tool Align Machine Vision, [Danal] added a Raspberry Pi alongside his existing 3D printing motion controller in addition to an upwards facing camera. A few lines of code (and a few hours of compiling OpenCV) later, and he had himself a circle-detecting script that automatically cycles through each tool, detects the nozzle center, and calculates an offset for each tool that’s stored into the machine’s configuration file. If that’s not nifty enough, he’s made the entire setup open-source, and he included both an installation script for compiling OpenCV and a well-written set of step-by-step instructions.

In a world where most hobbyists approaches still solve this problem manually, this is leaps and bounds ahead of what we know, and it’s a great application of machine vision built on top of a stack of recognizable hardware and software. While this project was outfitted for a Jubilee running a Duet3 controller with a Raspberry Pi connected in “single-board computer” mode, the core features are readily adaptable to any other multi-tool machine with a similar control board stack. And for folks willing to poke under the hood, the project could even be extended to a standalone script that you can run on your PC locally to simply print the tool offsets separately.

Alongside TAMV, it’s refreshing that even a decade after 3D printers have been with us, we’re still finding ways to make these machines more capable. For more fresh hacks in this category, check out a new spin on using sharpie ink as a support material release agent.

Sadly, [Danal] has recently passed away in the last week, but we are grateful to capture a snapshot in the history of this person’s life.

Continue reading “Dial In Your Multi-Headed 3D Printer With 2020 Machine Vision” →

Lithophanes Ditch The Monochrome With A Color Layer

August 20, 2019 by Donald Papp 10 Comments

3D printed lithophanes are great, if a bit monochromatic. [Thomas Brooks] (with help from [Jason Preuss]) changed all that with a tool for creating color lithophanes but there’s a catch: you’ll need a printer capable of creating multi-color prints to do it.

A video (embedded below) begins with an intro but walks through the entire process starting around the 1:26 mark. The lithophane is printed as a single piece and looks like most other 3D printed lithophanes from the front, but the back is different. The back (which is the bottom printed layer) is made of up multiple STL files, one for each color, and together creates something that acts as a color filter. When lit from behind, light passes through everything and results in an image that pops with color in ways that lithophanes normally do not.

As seen from the front, which is the top printed layer.

The back of the lithophane is printed in multiple colors, and acts as a color filter.

The demo print was created with a printer equipped with a Palette 2, an aftermarket device that splices together filament from different spools to create multicolored prints, but we think a Prusa printer with an MMU (multi material upgrade) should also do the trick.

[Thomas] already has a lot of ideas on how to improve the process, but these early results are promising. Need a gift? Lithophanes plus LED strips make great lamps, and adding a cheap clock movement adds that little extra something.

Continue reading “Lithophanes Ditch The Monochrome With A Color Layer” →