partially finished print, with the embedded animation

Flip Book Animations On The Inside Of 3D Prints

May 4, 2022 by Anne Ogborn 5 Comments

We’ve all seen 3D printed zoetropes, and drawn flip book animations in the corner of notebooks. The shifting, fluid shape of the layers forming on a 3D printer is satisfying. And we all know the joy of hidden, nested objects.

Hackaday alumnus [Caleb Kraft] has a few art pieces that all reflect all these. He’s been making animations by recording a 3D printer. The interesting bit is that his print is made of two objects. An outer one with normal infill that gives a solid form, and a layer cake like inner one with solid infill. It’s documented in this video on YouTube.

There are lots of things to get right. The outer object needs to print without supports. The thickness of the “layer cake” layers determines the frame rate. I had to wonder how he triggered the shutter when the head wasn’t in the way.

His first, experimental, piece is the classic ‘bouncing ball’ animation, inside a ball, and his mature piece is Eadward Muybridge’s “The Horse, In Motion” inside a movie camera.

We’ve covered [Caleb Kraft] before, of course. His Moon On A Budget piece is wonderful. And we’ve covered a number of 3D printer animations. and 3D zoetropes. We particularly were drawn to this one.

Thanks [jmc] for the tip!

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Wearable Electronics Takes The 3D Printing Route

May 3, 2022 by Jenny List 6 Comments

There was a time when a cheap 3D printer was almost certain to mean an awful kit of parts, usually a so-called “Prusa i3”, which was of course as far away in quality from the machines supplied by [Josef Průša] himself as it’s possible to get. But as Chinese manufacturers such as Creality have brought machines with some quality and relaibility into the budget space these abominations have largely been crowded out. There are still cheap 3D printers to be found though, and it’s one of these that [3D Printing Professor] has mounted on his wrist (Nitter) for the ultimate in portable manufacturing.

The Easythreed K7 is a novel take on a 3D printer that positions the device more as a child’s toy than a desktop manufacturing solution. It’s somewhat limited in its capabilities by its tiny size but by all accounts it’s a usable machine, and at around $100 USD it’s about the cheapest 3D printer for sale on the likes of AliExpress. The wearable mount is probably best described as a forearm mount rather than a wrist mount, but has provision for a battery pack and a small roll of filament. And this contraption is claimed to work, but we maybe would think before committing to a day-long print with it.

This may be the smallest wearable 3D printer we’ve shown you so far, but it’s not the first. That achievement goes to Shenzhen maker [Naomi Wu], who strapped one on her back way back in 2017.

Thanks [J. Peterson] for the tip!

The eurorack rail piece, just printed in white plastic, not yet folded, with a folded example in the upper right corner

Bend Your Prints To Eliminate Supports

May 1, 2022 by Arya Voronova 37 Comments

When designing even a reasonably simple 3D-printable part, you need to account for all the supports it will require to print well. Strategic offsetting, chamfering, and filleting are firmly in our toolkits. Over time we’ve learned to dial our settings in so that, hopefully, we don’t have to fumble around with a xacto knife after the bed has cooled down. On Twitter, Chris shows off his foldable 3D print experiments (nitter) that work around the support problem by printing the part as a single piece able to fold into a block as soon as you pop it off the bed.

The main components of this trick seem to be the shape of the place where the print will fold, and the alignment of bottom layer lines perpendicular to the direction of the fold lines. [Chris] shows a cross-section of his FreeCad design, sharing the dimensions he has found to work best.

Of course, this is Twitter, so other hackers are making suggestions to improve the design — like this sketch of a captive wedge likely to improve alignment. As for layer line direction alignment, [Chris] admits to winging it by rotating the part in the slicer until the layer lines are oriented just right. People have been experimenting with this for some time now, and tricks like these are always a welcome addition to our toolkits. You might be wondering – what kinds of projects are such hinges useful for?

The example Chris provides is a Eurorack rail segment — due to the kind of overhangs required, you’d be inclined to print it vertically, taking a hit to the print time and introducing structural weaknesses. With this trick, you absolutely don’t have to! You can also go way further and 3D print a single-piece foldable Raspberry Pi Zero case, available on Printables, with only two extra endcaps somewhat required to hold it together.

Foldable 3D prints aren’t new, though we typically see them done with print-in-place hinges that are technically separate pieces. This trick is a radical solution to avoiding supports and any piece separation altogether. In laser cutting, we’ve known about similar techniques for a while, called a “living hinge”, but we generally haven’t extended this technique into 3D printing, save for a few manufacturing-grade techniques. Hinges like these aren’t generally meant to bend many times before they break. It’s possible to work around that, too — last time we talked about this, it was an extensive journey that combined plastic and fabric to produce incredibly small 3D printed robots!

We thank [Chaos] for sharing this with us!

Recycling Plastic Into Filament

April 28, 2022 by Bryan Cockfield 43 Comments

Plastic is a remarkable material in many ways. Cheap, durable, and versatile, it is responsible for a large percentage of the modern world we live in. As we all know, though, it’s not without its downsides. Its persistence in the environment is quite troubling, so any opportunity we can take to reduce its use is welcome. This 3D printed machine, although made out of plastic, is made out of repurposed water bottles that have been turned into the filament for the 3D printer.

While there’s not too much information available on the site, what we gather is that the machine cuts a specific type of plastic water bottle made out of PET plastic into strips, and then feeds the strips into a heated forming tool. The tool transforms the strips into the filament shape and spools them so they are ready to feed back into a 3D printer. As a proof of concept, it seems as though this machine was made from repurposed plastic, but it could also be made using whatever filament you happen to have on hand.

As far as recycling goes, this is a great effort to keep at least some of it out of landfills and oceans. Unfortunately, plastic can’t be recycled endlessly like metal, as it will eventually break down. But something like this could additionally save on some filament costs for those with access to these types of bottles. Other options for creating your own filament also include old VHS tapes, but you will likely need a separate machine for that.

a 3D printed box with a Terminator head watching a camera

Machine Vision Helps You Terminate Failing 3D Print Jobs

April 25, 2022 by Robin Kearey 13 Comments

If you’re a 3D printer user you’re probably familiar with that dreaded feeling of returning to your printer a few hours after submitting a big job, only to find that it threw an error and stopped printing, or worse, turned half a spool of filament into a useless heap of twisted plastic. While some printers come with remote monitoring facilities, [Kutluhan Aktar]’s doesn’t, so he built a device that keeps a watchful eye on his 3D printer and notifies him if anything’s amiss.

The device does this by tracking the movement of the print head using a camera and looking for any significant changes in motion. If, for example, the Y-axis suddenly stops moving and doesn’t resume within a reasonable amount of time, it will generate a warning message and send it to its owner through Telegram. If all three axes stop moving, then either the print is finished or some serious error occurred, both of which require user intervention.

The camera [Kutluhan] used is a HuskyLens AI camera that can detect objects and output a set of 3D coordinates describing their motion. A set of QR-like AprilTags attached to the moving parts of the 3D printer help the camera to identify the relevant components. The software runs on a Raspberry Pi housed in a 3D-printed enclosure with a T-800 Terminator head on top to give it a bit of extra presence.

[Kutluhan]’s description of the project covers lots of detail on how to set up the camera and hook it up to a Telegram bot that enables it to send automated messages, so it’s an interesting read even if you’re not planning to 3D print something to check on your 3D printer. After all, software like Octoprint has many similar features, but having an independent observer can still be a good safety feature to prevent some types of catastrophic failure.

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A Universal, Non-planar Slicer For 3D Printing Is Worth Thinking About

April 23, 2022 by Donald Papp 28 Comments

One may think that when it comes to 3D printing, slicing software is pretty much a solved problem. Take a 3D model, slice it into flat layers equal to layer height, and make a toolpath so the nozzle can create those layers one at a time. However, as 3D printing becomes more complex and capable, this “flat planar slicing” approach will eventually become a limitation because a series of flat slices won’t necessarily the best way to treat all objects (nor all materials or toolheads, for that matter.)

How a 20 mm cube looks when sliced in a cone-shaped plane.

[René K. Müller] works to re-imagine slicing itself, and shows off the results of slicing 3D models using non-planar geometries. There are loads of pictures of a 20 mm cube being sliced with a variety of different geometries, so be sure to give it a look. There’s a video embedded below the page break that covers the main points.

It’s all forward-thinking stuff, and [René] certainly makes some compelling points in favor of a need for universal slicing; a system capable of handling any geometry, with the freedom to process along any path or direction. This is a concept that raises other interesting questions, too. For example, when slicing a 20 mm cube with non-planar geometries, the resulting slices often look strange. What’s the best way to create a toolpath for such a slice? After all, some slicing geometries are clearly better for the object, but can’t be accommodated by normal hot ends (that’s where a rotating, tilted nozzle comes in.)

Such worries may not be an issue for most users at the moment, but it’s worth trying to get ahead of the curve on something like this. And lest anyone think that non-planar slicing has no practical purpose, we previously covered [René]’s demonstration of how non-planar slicing can reliably create 90° overhangs with no supports.

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Add Conductive Traces On Vacuum Formed Plastic With 3D Printing

April 22, 2022 by Anne Ogborn 3 Comments

Surface conductors on vacuum formed parts appear in many hacks, from cosplay armor to 3D touch pads and smart objects. But making them has always been painful. Either they had to be hand painted after forming, which looked sloppy and was labor intensive, or they had to be printed with some difficult to use stretchable ink tech. [Freddie Hong] and his group have another solution, using tech most hackers already have – a 3D printer and a vacuum former.

plastic tray with electrodes to sense foil wrapped chocolates — Smart tray created by this method.

They 3D print the traces with conductive PLA filament directly onto a base plastic sheet, and then vacuum form the whole thing. The filament is happy to deform when heated – it’s printer filament.

We like this process. We’ve found conductive filament isn’t reliably resistive across vertical layers, but is reliable in the XY plane. Their method only requires one layer. Also, they suggest 3D printing a layer of non conductive PLA atop most of the conductor, like a PCB solder mask.

Conductive filament has a fair bulk resistance. They suggest electroplating it before applying the top mask layer. They also are exploring 3D printing logos, stripes, and such with colored filament, or even making surface detail like rivets on model parts or adding thickness where the plastic thins during vacuum forming.

Designing the 3D print requires guessing what bit of plastic sheet ends up where in the vacuum formed final part. His group used a commercial program, t-sim, to do the prediction and Grasshopper to import the result into Rhino3D. This seems a lot for a home hacker. Drawing lines on a test sheet and vacuum forming seems simpler.

We’ve looked at vacuum forming before. We did a piece on 3D printing bucks , and covered [Ted Brull]’s Kevo vacuum former back in 2015.

Thanks to [howielowe] for the tip.