Just When You Thought Magnets Weren’t Magic; Magnets Are Mechanisms

March 21, 2016 by James Hobson 127 Comments

This is magic, big news, both, or neither. It’s so exciting to see magnets behave in this bizarre and wonderful way that we think it’s hard to forecast where this will go. Shown above is a pair of magnets that have several modes of operation. They attract each other, but repel when less than a centimeter apart. However, give one a twist and the two will strongly attract.

The behavior is thanks to a new process of 3D printing magnets to manipulate where the fields occur. With the behavior just described, they would function well as a cabinet latch which has soft close and positive lock, all built into two magnets.

This comes from one of our favorite YouTube channels, [SmarterEveryDay], who just toured Polymagnet — a company that has figured out how to actually print magnetic fields.

So how the heck does it work? Well, your standard magnet has a north face on one side, and a south face on the other — creating a magnetic loop between the two. But what if you could put north and south on the same side of the magnet, and vary their position and size? It means you can control the magnetic field down to the magnetic pixel, or as Polymagnet calls them — a Maxel.

Here you can see some magnetic film (which reacts visually to magnetic fields) put on top of the two parts of the demo magnet. The printed design is very similar to a mechanical mechanism. We’d explain more, but [Destin] does a great job teaching about the tech in the video found below.

Is this the dawn of magnetic mechanisms? We certainly have never seen anything like it.

Continue reading “Just When You Thought Magnets Weren’t Magic; Magnets Are Mechanisms” →

Ask Hackaday MRRF Edition: 3D Printers Can Catch Fire

March 21, 2016 by Gerrit Coetzee 79 Comments

[Jay] out of the River City Labs Hackerspace in Peoria, IL cleared out a jam in his printer. It’s an operation most of us who own a 3D printer have performed. He reassembled the nozzle, and in a moment forgot to tighten down the grub nut that holds the heater cartridge in place. He started a print, saw the first layer go down right, and left the house at 8:30 for work. When he came back from work at 10:30 he didn’t see the print he expected, but was instead greeted by acrid smoke and a burnt out printer.

The approximate start time of the fire can be guessed by the height of the print before failure.

As far as he can figure, some time at around the thirty minute mark the heater cartridge vibrated out of the block. The printer saw a drop in temperature and increased the power to the cartridge. Since the cartridge was now hanging in air and the thermistor that reads the temperature was still attached to the block, the printer kept sending power. Eventually the cartridge, without a place to dump the energy being fed to it, burst into flame. This resulted in the carnage pictured. Luckily the Zortrax is a solidly built full metal printer, so there wasn’t much fuel for the fire, but the damage is total and the fire could easily have spread.

Which brings us to the topics of discussion.

How much can we trust our own work? We all have our home-builds and once you’ve put a lot of work into a printer you want to see it print a lot of things. I regularly leave the house with a print running and have a few other home projects going 24/7. Am I being arrogant? Should I treat my home work with a lesser degree of trust than something built by a larger organization? Or is the chance about the same? Continue reading “Ask Hackaday MRRF Edition: 3D Printers Can Catch Fire” →

MRRF 3D Printing Spectacular

March 19, 2016 by Brian Benchoff 18 Comments

MRRF, the Midwest RepRap Festival, is in full swing right now. The venue is packed, attendance is way up this year, and the panorama is impressive:

Panoramamini — The 2016 Midwest RepRap Festival. Click to embiggen.

New Printers

MRRF is not really a trade show. Yes, there are companies here (Google is picking up the tab for Chinese food tonight), but this is assuredly a community-based event around open source hardware. That said, Lulzbot is here, SeeMeCNC is hosting, E3D, and Ultimachine are all here. This year, there are a few new printers.

Lulzbot’s Taz 6 – the latest update to their flagship printer made its first public appearance at MRRF this year. A product update from Lulzbot isn’t like a product announcement from a normal company. Lulzbot is using rapid prototyping for manufacturing (!). They can iterate quickly and release two new printers in the time it takes Stratasys to come up with a design. This also means the releases are incremental.

Click past the break for more photos and updates.

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MRRF: Jellybox, A STEM-Oriented Printer

March 19, 2016 by Kristina Panos 24 Comments

It’s the first full day of fun here at the Midwest RepRap Festival. This year’s turnout is quite impressive—as I’m writing this, we’re an hour or so in and there are already hundreds of people and a couple of R2D2 units milling about.

The talks will begin in a few hours. This year MRRF has expanded to another building, which should tell you something about the growth of this festival. We are excited to hear [Filip] and [Ladi] give a presentation about Jellybox, a STEM-driven project he started to bring 3D printing into education in a comprehensive and hands-on way. The initial idea was based on [Jean Piaget]’s theory of constructionism. [Piaget] was a clinical psychologist who helped advance the idea that human learning is greatly influenced by connecting a person’s ideas with their experiences.

Building a Jellybox printer is about as easy as it gets, and takes about 4-6 hours depending on your skill level. The laser-cut clear acrylic panels are connected with zip ties that lock around 90° plastic brackets. The back panel even has a etched diagram that shows where all the connectors should go, and the wiring is neat and tidy by design. It’s meant to be easy to tear down so that teachers can use them again and again with middle and high school-aged students. The Jellybox is open-source; both the extruder and the hot end can be swapped out in a flash.

IMade3D offers one- and two-day intensive courses in the DC area that cover building a Jellybox and learning some things about 3D modeling. The kit is included in the price of admission. Jellybox kits will be available in a few weeks, but can be preordered today for $799.

Posture Sensor Reminds You To Sit Up Straight!

March 11, 2016 by James Hobson 24 Comments

Hey you! Are you slouching? Probably. It might not seem like such a bad thing to do, but if you plan on sitting comfortably at that desk for the next 5-10 years or so, you’ve really gotta watch your posture. This is a problem [Max] has been trying to solve for a while now — and now he’s attempting to do it with a posture sensor.

His first take on this project utilized an ultrasound range finder, mounted to the back of a chair. Once calibrated, you would have to maintain a certain distance from the back of your head to the sensor, thus, keeping your back straight. It worked, but it wasn’t the greatest.

Next up, he tried utilizing a webcam and facial recognition software to determine if he was slouching forwards, backwards, or (however unlikely), maintaining good posture. It was better than the first prototype, but still needed some refinement. Now he’s onto his third iteration — this time, a wearable posture sensor!

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Join Us At The Greatest 3D Printing Festival On Planet Earth

March 11, 2016 by Brian Benchoff 10 Comments

Winter is hanging on like clinical depression, which means it’s that time again for the greatest 3D-printing festival on the planet Earth. It’s time for the Midwest RepRap Festival, next weekend, March 18-20th in Goshen, Indiana.

I can’t explain why, but for some reason the Midwest RepRap Festival is an oasis of building, doing, and hacking right in the middle of the county fairgrounds for Elkhart County, Indiana. It’s free for everyone to attend. The event isn’t choked with vendors, leaving the people who actually do stuff left to fight over a few picnic tables on the outskirts of the venue. It is, by far, the most community-centered event we go to every year.

If you’re wondering what you can expect at a 3D printer convention in the middle of nowhere, check out a few of the posts we’ve published from MRRF over the last few years. We’ve seen 3D printed waffles, resin casting with 3D printed molds, bizarre movement platforms, Bioprinting, and stuff from Lulzbot. That’s just the stuff that has deserved its own Hackaday post: we’ve seen the world’s largest 3D printed trash can, R2D2, battle droids (it’s even money if BB-8 is going to show up this year), a Printer made out of K’nex, and the most beautiful 3D printer we’ve ever seen. There was a T-shirt cannon powered by 300 psi shop air.

Every year I write a post announcing that we’ll be heading to MRRF next week, simultaneously praising the event as one of the greatest ‘maker’ and ‘DIY’ meetups, while pointing out the local WalMart parking lot has a place to park horse-drawn buggies. Both observations are true. For one weekend a year, Goshen, Indiana is the place everyone reading Hackaday should go to, and that is why we are once again proud to sponsor this glorious event.

Ask Hackaday: Is PLA Biodegradable?

March 8, 2016 by Brian Benchoff 79 Comments

The most popular plastic for 3D printers is PLA – polylactic acid – a plastic that’s either derived from corn starch, inedible plant detritus, or sugar cane, depending where in the world it was manufactured. Being derived from natural materials, PLA is marketed as being biodegradable. You don’t need to worry about low-poly Pokemon and other plastic trinkets filling landfills when you’re printing with PLA, all these plastic baubles will return to the Earth from whence it came.

3D printers have been around for a few years now, and now objects printed in PLA have been around the sun a few times. A few of these objects have been completely forgotten. How’s that claim of being biodegradable holding up? The results are mixed, and as always, more data is needed.

A few weeks ago, [LazyGecko] found one of his first experiments in 3D printing. In 2012, he was experimenting with tie dying PLA prints by putting his prints in a jar filled with water and blue dye. This jar was then placed in the back of his cupboard and quickly forgotten. 3.5 years later, [LazyGecko] remembered his experiment. Absolutely nothing happened, save for a little bit of blue dye turning the print a pastel baby blue. The print looks and feels exactly like the day it came off the printer.

[LazyGecko]’s blog post was noticed by [Bill Waters], and he has one datum that points to PLA being biodegradable. In 2015, [Bill] printed a filter basket for his fish tank. The first filter basket worked well, but made a small design change a week later, printed out another, and put the first print in storage. He now has two nearly identical prints, one in constant use in a biologically interesting environment, the other sitting on a shelf for a year.

[Bill]’s inadvertent experiment is very close to the best possible experimental design to make the case for PLA biodegradability. The 3D printed filter basket in constant use for a year suffered significant breakdown, and the honeycomb walls are starting to crumble. The ‘inert’ printed filter basket looks like it just came off the build plate.

If that’s not confusing enough, [Bill] also has another print that has spent a year in a fish tank. This end cap for a filter spray bar didn’t see any degradation, despite being underwater in a biologically active environment. The environment is a little different from a filter basket, though; an aquarium filter is designed to break down organics.

To answer the question, ‘is PLA biodegradable,’ the most accurate answer is, ‘maybe’. Three data points in uncontrolled environments isn’t enough to draw any conclusions. There are, undoubtedly, more forgotten 3D prints out there, and more data to back up the claim of PLA being biodegradable.

This is where you come in. Do you have some forgotten prints out there? Your input is needed, the fruits of your labors are evidence, your prints might be decaying and we want to know about it below.