Active Strain Relief For 3D-Printer Filament

February 19, 2019 by Dan Maloney 26 Comments

Buying 3D-printer filament is little like eating potato chips: you can’t stop at just one. You start with basic black PLA, then you need a particular color for a special project, then you start experimenting with different plastics, and before you know it, you’ve got dozens of reels lined up. Trouble is, unless you move the in-use reel right over the printer, the filament can get a bit unruly as the printer sucks it up. What to do?

How about building an active strain relief system for your filament collection? That what [Daniel Harari] chose to do, and we have to say that it looks pretty slick. The idea is to keep the filament slack before it enters the printer’s extruder no matter where the reel is positioned relative to the printer. The active bit is a little like a low-force extruder, using a couple of pinch rollers from an old 2D-printer to pay out filament when needed. A clever sensor, consisting of a 3D-printed funnel and a copper wire contact loop, detects when the printer has taken up all the slack in the filament and triggers a payout from the feeder. In a nice touch, the feeder motor is controlled by a couple of 555s rather than a microcontroller. The short clip below shows the feeder being triggered and paying out a little more slack.

In the final analysis, this is just another in a long series of filament management projects, from dry-boxes to filament meters to end-of-spool alarms. It may be overkill, but [Daniel] put a lot of thought into it, which we always appreciate.

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Entry-Level SLA Printer Gets Upgrades, Prints Better

February 18, 2019 by Dan Maloney 12 Comments

Fused-deposition modeling (FDM) printers have the lion’s share of the 3D-printing market, with cheap, easy-to-use printers slurping up thousands of kilos of filament every year. So where’s the challenge with 3D-printing anymore? Is there any room left to tinker? [Physics Anonymous] thinks so, and has started working on what might be the next big challenge in additive manufacturing for the hobbyist: hacking cheap stereolithography (SLA) printers. To wit, this teardown of and improvements to an Anycubic Photon printer.

The Photon, available for as little as $450, has a lot going for it in the simplicity department. There’s no need to worry about filament and extruder issues, since the print is built up a layer at a time by photopolymerization of a liquid resin. And with but a single moving part – the build platform that rises up gradually from the resin tank on a stepper-driven lead screw – SLA printers don’t suffer from the accumulated errors of three separate axes. But, Anycubic made some design compromises in the motion control area to meet their price point for the Photon, leaving a perfect target for upgrades. [Physics Anonymous] added quality linear bearings to each side of the OEM vertical column and machined a carrier for the build platform. The result is better vertical positioning accuracy and decreased slop. It’s a simple fix that greatly improves print quality, with almost invisible layers.

Sadly, the Photon suffered a major, unrelated injury to its LCD screen, but it looks like [PA] will be able to recover from that. We hope so, because we find SLA printing very intriguing and would like to dive right in. But maybe we should start small first.

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Identifying A 3D Printer From A 3D Print

February 17, 2019 by Richard Baguley 37 Comments

A TV crime show I saw recently centered on the ability of forensic scientists to identify a plastic bag as coming from a particular roll: it’s all down to the striations, apparently. This development isn’t fiction, though: researchers at the University of Buffalo have figured out how to identify the individual 3D printer that produced a particular print. The development, called PrinTracker, uses unique differences in the way a printer lays down print material to identify a printer with a claimed 94 percent accuracy.

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The Magnetic Rubik’s Cube

February 16, 2019 by Lewin Day 6 Comments

Ernő Rubik has much to answer for when it comes to the legacy of his namesake cube. It has both enthralled and tormented generations, allowing some to grandstand in the playground while others are forced to admit defeat in the face of a seemingly intractable puzzle. It just so happens that [Tom Parker] has been working on a Rubik’s cube with a novel magnetic design.

Yes, that’s right – [Tom]’s cube eschews the traditional rotating and sliding mechanism of the original cube, instead replacing it all with magnets. Each segment of the cube, along with the hidden center piece, is 3D printed. Through using a fused deposition printer, and pausing the print at certain layers, it’s possible to embed the magnets inside the part during the printing process.

[Tom] provides several different versions of the parts, to suit printers of different capabilities. The final cube allows both regular Rubik’s cube movements, but also allows for the player to cheat and reassemble it without having to throw it forcefully against the wall first like the original toy.

It’s an interesting build, and a great one to get to grips with the techniques involved in embedding parts in 3D prints. It may not be capable of solving itself, but we’ve seen another build that can pull off that impressive feat. Video after the break.

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Understanding Math Rather Than Merely Learning It

February 15, 2019 by Al Williams 45 Comments

There’s a line from the original Star Trek where Khan says, “Improve a mechanical device and you may double productivity, but improve man and you gain a thousandfold.” Joan Horvath and Rich Cameron have the same idea about improving education, particularly autodidacticism or self-learning. They share what they’ve learned about acquiring an intuitive understanding of difficult math at the Hackaday Superconference and you can watch the newly published video below.

The start of this was the pair’s collaboration on a book about 3D printing science projects. Joan has a traditional education from MIT and Rich is a self-taught guy. This gave them a unique perspective from both sides of the street. They started looking at calculus — a subject that scares a lot of people but is really integral (no pun intended) to a lot of serious science and engineering.

You probably know that Newton and Leibniz struck on the fundamentals of calculus about the same time. The original papers, however, were decidedly different. Newton’s approach was more physical and less mathematical. Leibniz used formal logic and algebra. Although both share credit, the Leibniz notation won out and is what we use today.

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This 3D Printed LED Softbox Really Shines

February 10, 2019 by Tom Nardi 8 Comments

Generally speaking, objects made on desktop 3D printers are pretty small. This is of course no surprise, as filament based printers are fairly slow and most don’t have very large beds to begin with. Most people don’t want to wait days for their project to complete, so they use 3D printed parts where it makes sense and supplement them with more traditional components such as aluminum extrusion wherever possible. But not always…

This 3D printed photography softbox created by [Nicholas Sherlock] doesn’t take the easy way out for anything. With the exception of the LEDs and the electronics to drive them, everything in the design has been printed on his Prusa i3. It wasn’t the easiest or fastest way to do it, but it’s hard to argue with the end result. Perhaps even more impressive than the final product is what it took to get there: he actually had to develop a completely new style of part infill he’s calling “Scattered Rectilinear” to pull it off.

Overall the design of the light itself isn’t that complex, ultimately it’s just a box with some LEDs mounted at the back and a pretty simple circuit to control their intensity. The critics will say he could have just used a cardboard box, or maybe wood if he wanted something a little bit stronger. But the point of this project was never the box itself, or the LEDs inside it. It’s all about the diffuser.

[Nicholas] forked Prusa’s version of Slic3r to add in his “Scattered Rectilinear” infill pattern, which is specifically designed to avoid the standard “ribs” inside of a 3D printed object. This is accomplished with randomized straight infill passes, rather than the traditionally overlapped ones. The inside of the print looks very reminiscent of fiberglass mat, which is perhaps the best way to conceptualize its construction. In terms of the final part strength, this infill is abysmal. But on the plus side, the light from the LEDs passing through it emerges with a soft pleasing look that completely obscures the individual points of light.

Anyone with a big enough 3D printer can run off their own copy of his light, as [Nicholas] has released not only his forked version of Slic3r but all of the STL files for the individual components. He’s also put together an exceptionally well documented Thingiverse page that has instructions and detailed build photos, something that’s unfortunately very rare for that platform.

If you’re in the market for a DIY softbox and don’t have a 3D printer handy, fear not. We’ve covered a few that you can build with more traditional methods, as well as several tips and tricks which you can use to get the most out of your photos and videos.

Kinematic Mount For 3D Printer Bed Shows Practical Design

February 9, 2019 by Donald Papp 8 Comments

Aluminum bed with new kinematic mount and base on printer *Son of Megamax*, at the Milwaukee Makerspace

[Mark Rehorst] has been busy designing and building 3D printers, and Son of Megamax — one of his earlier builds — needed a bed heater replacement. He took the opportunity to add a Kelvin-type kinematic mount as well. The kinematic mount and base efficiently constrain the bed in a controlled way while allowing for thermal expansion, providing a stable platform that also allows for removal and repeatable re-positioning.

After a short discussion regarding the heater replacement, [Mark] explains the design and manufacture of his kinematic mount. Of particular note are the practical considerations of the design; [Mark] aimed to use square aluminum tubing as much as possible, with machining requirements that were easily done with the equipment he had available. Time is a resource after all, and design decisions that help one get something working quickly have a value all their own.

If you’re still a bit foggy on kinematic mounts and how they work, you’re not alone. Check out our coverage of this 3D-printed kinematic camera mount which should make the concept a bit clearer.