Wrapping Up The Last Midwest RepRap Festival

The Midwest RepRap Festival is over – forever. This was the last one. Apparently enough people complained that Goshen, Indiana wasn’t in the midwest. The number of Dairy Queens I passed contradicts this, but whatever. Next year, there’s going to be a different con in Goshen. Same content, different name. If you have a suggestion, you know where to put it.

I promised the world’s largest 3D printed trash can, and I gave you the world’s largest 3D printed trash can. This gigantic orange vase was printed on the PartDaddy, SeeMeCNC’s 18-foot tall delta printer a few months ago at the NYC Maker Faire. I have been using this as a trash can in my basement since then, making me one of the only people who have their trash can on Wikipedia.

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A failed print on Saturday morning

Speaking of the PartDaddy, this is what a fail looks like. The first PartDaddy print was a Groot, a 13-hour long print job. It was left running overnight, but it ran out of PLA pellets sometime around 4 in the morning. If you’re wondering what the black band is around the Groot’s face is, here’s the breakdown:

The PartDaddy sucks PLA pellets up from a trash can (that’s not 3D printed), and dispenses it into a hopper above the print head. This hopper was 3D printed on the PartDaddy, and there is still a little bit of colarant dust in there. When the PLA pellets run out, that dust is embedded in the extrusion. When you realize that masterbatch is only about 5% of the finished plastic, it doesn’t take much black dust to discolor a print.

Yes, this is a print fail that could have been fixed by having an all-night bash. A few other people left their printers running overnight including [The Great Fredini] and his Scan-A-Rama. This was a Rostock Max that had something wonky happen with the Bowden. There was filament everywhere.

How about some Star Wars droids? An R2 from the Droid Builder’s Club was there, but there was also the beginnings of a completely 3D printed Roger. While we’re on the subject of plastic robots that will fall apart at a moment’s notice, there was a K’NEX 3D printer. Yes, it’s made almost entirely out of K’NEX, and it did work at one time. Those orange parts sitting next to it? Those came out of the K’NEX printer.  If you’re looking for the definitive RepStrap, there ‘ya go.

 

NEW FILAMENTS

For the last few months, metal filaments – PLA with tiny particles of copper, brass, bronze, iron, or aluminum have been available. MRRF was the first place where you could see them all together. A few things of note: these filaments are heavy – the printed objects actually feel like they’re made out of metal. They’re actually metal, too: the iron-based filaments had a tiny bit of red corrosion, and the Lincoln death mask above was treated with acetic acid. These filaments are also expensive, around $100 for 1kg. Still, if you want to print something that will be around in 100 years, this is what you should get.

The most beautiful printer ever

MRRF should have had a contest for the best looking 3D printer at the show. A beautiful delta from Detroit Rock City would have won:

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DSC_0075That white hexagon in the center is a ceramic PCB that I’m told cost an ungodly amount of money. Underneath the ceramic build plate, there’s a few Peltiers between the bed and the large copper heat sink. The heat sink is connected to the three risers by heat pipes, making the entire printer one gigantic heat sink. Why would anyone make such an amazing art deco printer? For this.

Because you can use Peltiers to heat and cool a bed, a little bit of GCode at the end of a print will cool the bed to below room temperature. If you do your design right, this means the print will just fall over when it’s done. When the print bed is cooling, you can actually hear the bond between the bed and print cracking. It’s beautiful, it’s cool, and I’m told this printer will make its way to hackaday.io soon.


There you go, the best and coolest from the last Midwest RepRap Festival ever. There will never be another one. It only needs a better name, and [John] at SeeMeCNC is great at coming up with names. Just ask what VIP is a backronym of.

I told you there would be a T-shirt cannon. That’s 300 PSI shop air.

Before Film There Were Zoetropes. Now We Have 3D Printed Zoetropes!

Reddit user [eyelandarts] has produced a rather unique 3D printing project. A 3D printed Zoetrope.

You see, a zoetrope was a device that created an animation effect that pre-dates film technology. It would create the illusion of motion much like a flip book does, but with a spinning cylindrical wall with slots cut into it. As the cylinder spins, you catch a glimpse of the animation through the slots. But, it’s just a 2-dimensional animation — what if you replaced it with an ever changing 3D model?

It’s actually been done before. A long time ago in fact. In 1887, [Etienne-Jules Marey] created a large zoetrope to animate plaster models of a bird in flight. Fast forward to today, and [eyelandarts] has 3D printed something similar — but ditched the cylindrical wall. Instead, a strobe light is used to see the animation!

The end result is quite awesome if we do say so our-selves. For another fun take on Zoetropes — how about a digital one made out of tiny LCD screens?

Siezure-warning… there’s a very flash-tastic demo gif embedded after the break if you’re brave enough to view such a thing.

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MRRF: Hot Ends, Extruders, Extremely Posh Brits, And Stoic Swedes

As far as locations for the Midwest RepRap Festival go, it’s not exactly ideal. This is a feature, not a bug, and it means only the cool people come out to the event. There were a few people travelling thousands of miles across an ocean, just to show off some cool things they built.

Two Colors, One Nozzle

[Sanjay] and [Josh] from E3D came all the way from merry olde England to show off a few of their wares. The star of their show was the Cyclops extruder, a dual-extrusion hot end that’s two input, one output. Yes, two colors can come out of one nozzle.

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If you see a printer advertised as being dual extrusion, what you’re going to get is two extruders and two hot ends. This is the kludgy way to do things – the elegant solution is to make two colors come out of one nozzle.

The guys from E3D were showing off a few prints from their Cyclops nozzle that does just that, including a black and red poison dart frog, and a blue and white octopus. The prints looked amazing, and exactly what you would expect from a two-color print.

Rumor has it the development of the Cyclops involved extruding two colors, freezing the nozzle, and putting it in the mill just to see how the colors mixed. I didn’t see those pictures, but there’s a lot of work that went into this hot end.

The Power of Two Extruders

[Martin] of bondtech.se came to MRRF all the way from Sweden. He was there showing off his new extruder.

The extruder uses a normal stepper motor, but instead of the usual knurled or threaded feed wheel and bearing to push filament though, he’s using two counter-rotating feed wheels attached to a planetary gear system. That’s a lot of torque that doesn’t distort or strip the filament. When you consider all the weird filaments that are coming out – ninjaflex, and even 3D printable machinable wax filament, this is extremely interesting.

Even if your filament isn’t exactly 1.75 or 3mm in diameter, this setup will still reliably push plastic; there is a bolt that will move one of the feed wheels in and out 0.4mm.

[Martin] had a pair of his extruders hooked up to a strain gauge, and it’s strong enough to lift your printer off the table without stripping the filament. Here’s a video of that demo from the bondtech page.

MRRF: Flexible 3D Printing

The concession stand at the Midwest Rep Rap Festival did not disappoint when it came to the expected fare: hot dogs, walking tacos, and bananas for scale. But the yummiest things there could not be bought—the Nutella prints coming off the Ultimaker² at the structur3D booth.

3D printed gasket
Flexible gasket printed in silicone atop a rigid 3D printed engine block.

Hey, what? Yes, an Ultimaker² that can print in Nutella, icing sugar, silicone, latex, wood filler, conductive ink, polyurethane, peanut butter, and a growing list to which you should contribute. This is possible because of their Discov3ry Universal Paste Extruder add-on, which is compatible with most filament printers, especially those that use a RAMPs or Arduino control board.

A large syringe containing the substance of your choice is loaded business end up in the Discov3ry. It gets pushed through tubing that runs to the print head and out through one of many commonly available polypropylene or stainless steel tips. The structur3D team has found that printing on waxed paper works best for the materials they’ve proven out. Each syringe holds 60cc of stuff, and the Discov3ry comes with three of them. They are currently available for pre-order, with a shipping forecast of early summer.

3D printed motorcycle

3D Printed Motorcycle Weighs Only 18kg

After discovering 3D printing a few years ago, [Jonathan Brand] was hooked. He loved the ability to design things on a computer, and then have them realized as a real 3D object he can touch — sometimes within hours of doing the CAD work. He’s always wanted a motorcycle, but it was never the right time so at long last he decided to print one.

First off — no, it doesn’t actually work — it’s a 1:1 scale model of a 1972 Honda CB500. But it is an amazing testament to 3D printing and prototyping. He’s been working on it for almost as long as he’s had a 3D printer, and while he didn’t quote exactly how long it took to print everything, we’re guessing its in the thousands of hours.

In fact, he printed tons of components, labeled them, and organized them for up to a year before even being able to assemble them together. Talk about project dedication.

He’s even designed loose fits for moving parts — the wheels spin! To give it the cool transparent look, each part is actually almost completely hollow — with thin wall thickness of only about a millimeter. Because of this, the whole bike only weighs 18kg.

For a slightly more functional large-scale 3D print — how about printing your own colorful kayak?

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MRRF: Mostly Harmless 3D Printed Arms

The Midwest RepRap Festival isn’t just people hanging out with their 3D printers all weekend; There are also people bringing all the things they made with their 3D printers. There was an R2D2 and half of a B1 Battle Droid, a 3D printed quadcopter and of course 3D printed weaponry. [Ryan] and [Kane] from Mostly Harmless Arms brought a collection of their totally not trademark infringing not-Nerf guns.

The guys have a few designs for guns that shoot silicone-tipped extruded foam darts much further than a Nerf gun. There’s a bow, a more traditional spring-powered blaster, and a crossbow. All the designs with the exception of a few pipes and tubes and springs are 3D printed, and all the parts are small enough to fit on an 8″ bed. The darts are made with a dome mold for silicon and insulation foam that’s normally wedged in window and door frames. They’re dusted with cornstarch to prevent sticking, although in the video below there were a few jams. That’s to be expected; there was a camera around.

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Take A Spin On This Voice-Controlled 3D Scanning Rig

[Aldric Negrier] wanted to make 3D-scanning a person streamlined and simple. To that end, he created this voice-controlled 3D-scanning rig.

[Aldric] used a variety of hacking skills to make this project, and his thorough Instructable illustrates this nicely. Everything from CNC milling to Arduino programming to 3D-printing was incorporated into the making of this rig. Plywood was used to construct the base and the large toothed gear. A 12″ Lazy Susan bearing was attached to this gear to allow smooth rotation. In order to automate the rig, a 12V DC geared motor was attached to a smaller 3D-printed gear and positioned on the base. When the motor is on, the smaller gear’s teeth take the larger gear for a spin. He used a custom dual H-bridge motor driver made by a friend, which is connected to an Arduino Nano. The Nano is also connected to a Bluetooth module and an ultrasonic range finder. When an object within 1-35cm is detected on the rig for 3 seconds, the motor starts to spin, stopping when the object is no longer detected. A typical scan takes about 60 seconds.

This alone would have been a great project, but [Aldric] did not stop there. He wanted to be able to step on the rig and issue commands while being scanned. It makes sense if you want to scan yourself – get on the rig, assume the desired position, and then initiate the scan. He used the Windows speech recognition SDK to develop an application that issues commands via Bluetooth to Skanect, a 3D-scanning software. The commands are as simple as saying “Start Skanect.” You can also tell the motor to switch on or off and change its speed or direction without breaking form. [Aldric] used an Asus Xtion for a 3D-scanner, but a Kinect will also work. Afterwards, he smoothed his scans using MeshMixer, a program featured in previous hacks.

Check out the videos of the rig after the break. Voice commands are difficult to hear due to the background music in one of the videos, but if you listen carefully, you can hear them. You can also see more of [Aldric’s] projects here or on this YouTube channel.

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