Songbird, A Mostly 3D Printed Pistol That Appears To Actually Work

September 28, 2016 by Gerrit Coetzee 132 Comments

[Guy in a garage] has made a 3D printed gun that not only appears to fire in the direction pointed, it can also do it multiple times. Which, by the standard of 3D printed guns, is an astounding feat. He started with .22 rifle cartridges but has since upgraded and tested the gun with .357 rounds. The link above is a playlist which starts of with an in-depth explanation of the .22 version and moves through design iterations

This gun prints on a standard FDM printer. Other 3D printable guns such as the infamous Liberator or the 3D printed metal gun need more exotic or precise 3D printing to work effectively. The secret to this gun’s ability is the barrel, which can be printed in nylon for .22 cartridges, or in ABS plus a barrel liner for .22 and .357 caliber.

A barrel liner is one way to repair a gun that has aged and is no longer shooting properly. Simply put, it is a long hardened metal tube with rifling on the inside. Some guns come out of the factory with one, and a gunsmith simply has to remove the old one and replace it. Other guns need to be bored out before a liner can be installed.

The metal liner surrounded by plastic offers enough mechanical strength for repeat firings without anyone losing a hand or an eye; though we’re not sure if we recommend firing any 3D printed gun as it’s still risky business. It’s basically like old stories of wrapping a cracked cannon in twine. The metal tries to expand out under the force of firing, but the twine, which would seem like a terrible material for cannon making, is good in tension and when wrapped tightly offers more than enough strength to hold it all together.

This is also how he got the .357 version to work. The barrel slots into the gun frame and locates itself with a rounded end. However, with the higher energy from a .357 round, this rounded end would act as a wedge and split the 3D printed frame. The fix for this was simple. Glue it back together with ABS glue, and then wrap the end of the assembly with a cable tie.

This is the first 3D printed gun we’ve seen that doesn’t look like a fantastic way to instantly lose your hand. It’s a clever trick that took some knowledge of guns and gunsmithing to put together. Despite the inevitable ethical, moral, and political debate that will ensue as this sort of thing becomes more prevalent, it is a pretty solid hack and a sign that 3D printing is starting to work with more formidable engineering challenges.

Hackaday Prize Entry: The Strength Of 3D Printed Parts

August 6, 2016 by Gerrit Coetzee 16 Comments

[Sam Barrett] is doing something that is sorely needed. He’s doing real materials research on FDM parts.

There’s nothing wrong with the rough experiments like hanging a 1 L bottle of water from the end of a rectangular test print to compare strengths. We also have our rules-of-thumb, like expecting the print to perform at 30% of injection molded strength. But these experiments are primitive and the guidelines are based on hearsay. Like early metallurgy or engineering; 3D printing is full of made-up stuff.

What [Sam] has done here is really amazing. He’s produced a model of a printed ABS part and experimentally verified it to behave close enough to the real thing. He’s also set a method for testing and proposed a new set of questions. If it couldn’t be better, he also included his full research notebook. Make sure to read the FDMProperties-report (PDF) in the files section of Hackaday.io.

Sam finally answered a question we've had of what it looks like when the printer over extrudes. — Sam finally answered a question we’ve had of what it looks like when the printer over extrudes.

If research like this is being done elsewhere, it’s either internal to a large 3D printer manufacturer, or it’s behind a paywall so thorough only the Russians can help a regular peasant get through to them. Anyone with access to a materials testing lab can continue the work (looking at you every single engineering student who reads this site) and begin to help everyone achieve an understanding of 3D printed parts that could lead to some really cool stuff one day.

Are Your 3D Prints Toxic?

November 11, 2015 by Dan Maloney 78 Comments

With the rising popularity and increasing availability of 3D printers, it was inevitable that someone would start looking into the potential environmental impact presented by them. And now we have two researchers from the University of California Riverside sounding the alarm that certain plastics are toxic to zebrafish embryos (abstract only; full paper behind a paywall).

As is often the case with science, this discovery was serendipitous. Graduate student [Shirin Mesbah Oskui] was using 3D printed tools to study zebrafish embryos, a widely used model organism in developmental biology, but she found the tools were killing her critters. She investigated further and found that prints from both a Stratasys Dimension Elite FDM printer and from a Formlabs Form 1+ stereolithography printer were “measurably toxic” to developing zebrafish embryos. The resin-based SLA printed parts were far worse for the fish than the fused ABS prints – 100% of embryos exposed to the Form 1+ prints were dead within seven days, and the few that survived that long showed developmental abnormalities before they died. Interestingly, the paper also describes a UV-curing process that reduces the toxicity of the SLA prints, which the university is patenting.

Of course what’s toxic to zebrafish is not necessarily a problem for school kids, as the video below seems to intimate. Still, this is an interesting paper that points to an area that clearly needs more investigation.

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Codename Colossus: The HMC Boudicca

June 25, 2015 by Theodora Fabio 15 Comments

[Michael Sng], founder of [Machination Studio], wanted to create a toy line unlike anything the world has seen. He has recently completed the first production prototype in the Codename Colossus toy line: the HMC Boudicca. The egg-shaped HMC Boudicca is tank-like with a definite Metal Slug vibe, but it’s almost a disservice calling it a toy.

The HMC Boudicca is over 20″ tall. It is composed of over 400 parts, a majority of which are 3D-printed or laser-cut. Internal parts are FDM while the external pieces are SLS printed. It is a kinetic piece that walks in a hexapodal fashion, so there are lots of servos, motors, sensors, and LEDs, that are controlled by an Arduino. A lot of work and attention to detail was put into this prototype. The HMC Boudicca was designed to be easily disassembled with a Phillips screwdriver. The electronic components are all plug-in devices, so no soldering is required when it comes time to replace a sensor or servo.

Codename Colossus is a toy line that is made to order and intended to be artisanal in nature. Each piece will be individually hand-painted and assembled like the HMC Boudicca. While no official prices are posted yet on the site, we assume these are not going to be cheap. In fact, the site states that each piece will have a 2% markup from the previously sold price to help maintain the value of the pieces and control cost inflation. This could be a source of contention for potential buyers. It underscores [Michael’s] philosophy that Codename Colossus is meant to be a collectible work of art, an antithesis to mass production.

Regardless of the business strategy, we are interested in seeing any additional designs for this series. It would be fun to see a whole bunch of these marching as one robot army!

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