Autodrop3D Continues Working At 3D Printer Automation

June 6, 2019 by Roger Cheng 2 Comments

It is an unfortunate fact that 3D printers spend most of their time sitting idle, waiting for a human to remove finished prints or waiting for the next print to start. Hackers see such inefficiency as an open invitation to devise a better way, and we’ve seen several innovative ideas come across these pages. Some have since been abandoned, but others have kept going. At Maker Faire Bay Area 2019 we had the chance to revisit one presented as Autodrop3D.

We saw a much earlier iteration entered in our Hackaday Prize in 2017 and it was fascinating to see how the basic ideas have developed over the past few years. The most visible component of the system is their print ejection system, which has greatly improved in robustness. Because the mechanism modifies the print bed and adds significant mass, it is best suited to delta printers as their print bed remains static. The concept might be adaptable to printers where the print bed only has to move along Z axis, but for now the team stays focused on deltas. There were two implementations on display at Maker Faire: a large one built on a SeeMeCNC RostockMAX v4, and a small one built on a Monoprice Mini Delta.

The ejection system is novel enough by itself, but the hardware is only one part of the end-to-end Autodrop3D vision. Their full software pipeline starts with web-based CAD, to integrated slicing, to print queue management, before G-code is fed to a printer equipped with their ejection system.

We admire inventors who keep working away at turning their vision to reality, and we look forward to seeing what’s new the next time we meet this team. In the meantime, if you like the idea of an automated print ejection mechanism but want more cartoon style, look at this invention from MatterHackers.

Assessing Nozzle Wear In 3D-Printers

June 6, 2019 by Dan Maloney 15 Comments

How worn are your nozzles? It’s a legitimate question, so [Stefan] set out to find out just how bad 3D-printer nozzle wear can get. The answer, as always, is “It depends,” but exploring the issue turns out to be an interesting trip.

Reasoning that the best place to start is knowing what nozzle wear looks like, [Stefan] began by printing a series of Benchies with brand-new brass nozzles of increasing diameter, to simulate wear. He found that stringing artifacts, interlayer holes, and softening of overhanging edges and details all worsened with increasing nozzle size. Armed with this information, [Stefan] began a torture test of some cheap nozzles with both carbon-fiber filament and a glow-in-the-dark filament, both of which have been reported as nozzle eaters. [Stefan] found that to be the case for at least the carbon-fiber filament, which wore the nozzle to a nub after extruding only 360 grams of material.

Finally, [Stefan] did some destructive testing by cutting used nozzles in half on the mill and looking at them in cross-section. The wear on the nozzle used for carbon-fiber is dramatic, as is the difference between brand-new cheap nozzles and the high-quality parts. Check out the video below and please sound off in the comments if you know how that peculiar spiral profile was machined into the cheap nozzles.

Hats off to [Stefan] for taking the time to explore nozzle wear and sharing his results. He certainly has an eye for analysis; we’ve covered his technique for breaking down 3D-printing costs in [Donald Papp]’s “Life on Contract” series.

Continue reading “Assessing Nozzle Wear In 3D-Printers” →

3D Prints Turn Any Keyboard Isomorphic

June 1, 2019 by Brian Benchoff 4 Comments

In the history of weird musical instrument interfaces, isomorphic keyboards are a favorite. These keyboards look like a grid of buttons, but when you play them, the relative shapes of chords are always the same. The benefit? Just say no to five hundred years of clavier tradition. It looks cool, too. Theoretically, it’s easier to play independent of whatever key you’re in. [John Moriarty] has built one of these isomorphic keyboards, and unlike everything we’ve ever seen, there are no electronics. It’s all 3D printable and turns any MIDI keyboard into an isomorphic keyboard.

We have seen isomorphic (piano) keyboards before, from a slew of Cherry keyboard switches to a bunch of arcade buttons. There is one downside to these builds, and that is that it’s really just building a MIDI controller. [John]’s build is simply a 3D printable overlay for a traditional piano that turns any standard keyboard into an isomorphic keyboard. The advantage being that this is really just a few pounds of plastic to be printed out and not a mess of wiring and electronics. Simple, removable, reversible. Not bad.

This keyboard effectively adds two differently colored keytops to each key on a keyboard. The best explination of how this keyboard works is in this video, but the basic idea is that all the note names are grouped together by color; C flat, C natural, and C sharp are all blue, for example. This means a third interval is two colors away, and a minor third is two colors to the right and one ‘row’ down. Yeah, it’s weird but that’s what an isomorphic keyboard is.

Since this is just a bunch of 3D printed parts meant to fit on any piano keybed, this is something that’s extremely easy to replicate. All the files for this keyboard overlay are available on Thingiverse, and [John] is offering to print these key tops for others without a 3D printer.

3D Printering: The Past And Future Of Prusa’s Slicer

May 24, 2019 by Tom Nardi 41 Comments

If you own a desktop 3D printer, you’re almost certainly familiar with Slic3r. Even if the name doesn’t ring a bell, there’s an excellent chance that a program you’ve used to convert STLs into the G-code your printer can understand was using Slic3r behind the scenes in some capacity. While there have been the occasional challengers, Slic3r has remained one of the most widely used open source slicers for the better part of a decade. While some might argue that proprietary slicers have pulled ahead in some respects, it’s hard to beat free.

So when Josef Prusa announced his team’s fork of Slic3r back in 2016, it wasn’t exactly a shock. The company wanted to offer a slicer optimized for their line of 3D printers, and being big proponents of open source, it made sense they would lean heavily on what was already available in the community. The result was the aptly named “Slic3r Prusa Edition”, or as it came to be known, Slic3r PE.

Ostensibly the fork enabled Prusa to fine tune print parameters for their particular machines and implement support for products such as their Multi-Material Upgrade, but it didn’t take long for Prusa’s developers to start fixing and improving core Slic3r functionality. As both projects were released under the GNU Affero General Public License v3.0, any and all of these improvements could be backported to the original Slic3r; but doing so would take considerable time and effort, something that’s always in short supply with community developed projects.

Since Slic3r PE still produced standard G-code that any 3D printer could use, soon people started using it with their non-Prusa printers simply because it had more features. But this served only to further blur the line between the two projects, especially for new users. When issues arose, it could be hard to determine who should take responsibility for it. All the while, the gap between the two projects continued to widen.

With a new release on the horizon that promised to bring massive changes to Slic3r PE, Josef Prusa decided things had reached a tipping point. In a recent blog post, he announced that as of version 2.0, their slicer would henceforth be known as PrusaSlicer. Let’s take a look at this new slicer, and find out what it took to finally separate these two projects.

Continue reading “3D Printering: The Past And Future Of Prusa’s Slicer” →

Go Back In Time With A Laser Cut Wood 3D Printer Kit

May 23, 2019 by Tom Nardi 15 Comments

About a decade ago, the only way the average hacker was getting their hands on a desktop 3D printer was by building it themselves from a kit. Even then, to keep costs down, many of these kits were made out of laser cut wood. For a few years, wooden printers from companies like MakerBot and PrintrBot were a common sight in particularly well equipped hackerspaces. But as the market expanded and production went up, companies could afford to bend metal and get parts injection molded; the era of the wooden 3D printer was over nearly as soon as it had started.

But [Luke Wallace] thinks there’s still some life left in the idea. For his entry into the 2019 Hackaday Prize, he’s proposing a revival of the classic laser cut 3D printer kit. But this time, things are a bit different. Today, laser cutters are cheap enough that these kits could conceivably be manufactured at your local hackerspace. With a total bill of materials under $100 USD, these kits could be pumped out for less than the cheapest imports, potentially driving adoption in areas where the current options are too expensive or unavailable.

Of course, just a laser cut wood frame wouldn’t be enough to break the fabled $100 barrier. To drive the cost down even farther, [Luke] has redesigned essentially every component so it could be made out of wood. If its not electronic, there’s a good chance its going to be cut out of the same material the frame is made out of. Probably the biggest change is that the traditional belt and pulley system has been replaced with rack and pinion arrangements.

After cutting all the pieces, essentially all you need to provide is the stepper motors, a RAMPS controller, the hotend, and the extruder. He’s even got a design for a laser cut wood extruder if you want to go back to the real olden days and save yourself another few bucks. Or skip the LCD controller and just run it over USB.

But what do the prints look like? [Luke] has posted a few pictures of early test pieces on the project’s Hackaday.io page, and to be honest, they’re pretty rough. But they don’t look entirely unlike the kind of prints you’d get on one of those early printers before you really got it dialed in, so we’re interested in seeing how the results improve with further refinements and calibration. (Editor’s note: Since writing this, he got backlash compensation up and running, and it looks a ton better already. Very impressive for something running on wooden gears!)

A Compact Strain Wave Gear Assembly

May 20, 2019 by Jenny List 8 Comments

Strain wave gearing is a clever way to produce a high-efficiency, high ratio gearbox within a small space. It involves an outer fixed ring of gear teeth and an inner flexible ring of teeth which are made to mesh with the outer by means of an oval rotor distorting the ring. They aren’t cheap, so [Leo Vu] has had a go at producing some 3D-printable strain wave gearboxes that you could use in your robotic projects.

He’s created his gearbox in three ratios, 1:31, 1:21 and 1:15. It’s not the most miniature of devices at 145mm in diameter and weighing well over a kilogram, but we can still imagine plenty of exciting applications for it. We’d be curious as to how tough a 3D printed gear can be, but we’d expect you’ll be interested in it for modest-sized robots rather than Formula One cars. There’s a video featuring the gearbox which we’ve placed below the break.

This certainly isn’t the first strain wave gearset we’ve brought you, more than one 3D printed project has graced these pages. We’ve even brought you a Lego version. Continue reading “A Compact Strain Wave Gear Assembly” →

Transparent And Flexible Circuits

May 17, 2019 by Al Williams 4 Comments

German researchers have a line on 3D printed circuitry, but with a twist. Using silver nanowires and a polymer, they’ve created flexible and transparent circuits. Nanowires in this context are only 20 nanometers long and only a few nanometers thick. The research hopes to print things like LEDs and solar cells.

Of course, nothing is perfect. The material has a sheet resistance as low as 13Ω/sq and the optical transmission was as high as 90%. That sounds good until you remember the sheet resistance of copper foil on a PCB is about 0.0005Ω.

Continue reading “Transparent And Flexible Circuits” →