Powder Coating With A Fluidized Bed

December 25, 2017 by Dan Maloney 16 Comments

There’s no beating the beauty and durability of a high-quality powder-coated part. There’s just something about the look and feel of the finish that goes far beyond mere painting and makes it worth the effort and expense. The typical electrostatic spray powder-coating setup can be expensive, though, and not necessarily suitable for every workpiece.

Enter the fluidized-bed powder coating chamber, perfect for limited runs of small parts, and the brainchild of [Andrew Mayhall]. With a business providing furniture kits based on iron pipe, [Andrew] needed a way to finish flanges and fittings, and powder coating provided the best look. The fluidizer he built is a great alternative to spray coating; it blows air through a bed of fine thermoplastic granules, which causes them to act like a fluid. It’s similar to the fluidized-bed hot tub we recently featured, but on a much smaller scale and with different requirements based on the ultrafine particle size and aggregation properties of the powder. [Andrew] had to add mechanical agitation to achieve a homogeneous fluid bed, and after much experimentation he’s now able to dip preheated parts into the bed and achieve one-step powder coating. The video after the break shows some of the operational details.

Does electrostatic powder-coating sound like more of your thing? No problem – DIY solutions abound, and a homebrew oven to bake your parts may be as close as the nearest file cabinet.

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Robot Graffiti

September 13, 2017 by James Hobson 11 Comments

There’s talk of robots and AIs taking on jobs in many different industries. Depending on how much stock you place in that, it might still be fair to say the more creative fields will remain firmly in the hands of humans, right?

Well, we may have some bad news for you. Robots are now painting our murals.

Estonian inventor [Mihkel Joala] — also working at SprayPainter — successfully tested his prototype by painting a 30m tall mural on a smokestack in Tartu, Estonia. The creative procedure for this mural is a little odd if you are used to the ordinary painting process: [Joala] first takes an image from his computer, and converts it into a coordinate grid — in this case, about 1.5 million ‘pixels’. These pixels are painted on by a little cart loaded with five colours of spray paint that are able to portray the mural’s full palette once combined and viewed at a distance. Positioning is handled by a motor at the base of the mural controlling the vertical motion in conjunction with tracks at the top and bottom which handle the horizontal motion.

For this mural, the robot spent the fourteen hours trundling up and down a set of cables, dutifully spraying the appropriate colour at such-and-such a point resulting in the image of a maiden cradling a tree and using thirty cans of spray paint in the process.

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Making Metal Dominoes

April 11, 2017 by James Hobson 14 Comments

Nearly as versatile as a deck of playing cards, dominoes are a great addition to any rainy-day repertoire of game sets. [Apollo] from the Youtube channel [carbide3d] has manufactured for themselves a custom set of domino tiles replete with brass pips.

Cutting the bar stock to the appropriate size, [Apollo] ran a few test engravings and hole sizes for the brass pips. That done, all they had to do was repeat the engraving and milling process another couple dozen times, as well as all the requisite wet and dry sanding, and buffing. [Apollo] opted to use paint marker to add a little extra style to the tiles, and advises any other makers who want to do the same to set their engraving depth to .01″ so the paint marker won’t be rubbed off when buffing the pieces.

When it came to installing the brass balls, [Apollo] undersized the holes by .001″-.002″ for a snug press fit — adding that the hole depth is a little greater than half the ball’s diameter. They used 1/8″ balls for the pips, and 3/16 balls for the center of the tiles which also allows the tiles to be spun for a bit of fidgeting fun during play. Check out the build video after the break.

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A Look Into The Future Of Slicing

April 7, 2016 by Gerrit Coetzee 48 Comments

I’ve had a few conversations over the years with people about the future of 3D printing. One of the topics that arises frequently is the slicer, the software that turns a 3D model into paths for a 3D printer. I thought it would be a good idea to visualize what slicing, and by extension 3D printing, could be. I’ve always been a proponent of just building something, but sometimes it’s very easy to keep polishing the solution we have now rather than looking for and imagining the solutions that could be. Many of the things I’ll mention have been worked on or solved in one context or another, but not blended into a cohesive package.

I believe that fused deposition modelling (FDM), which is the cheapest and most common technology, can produce parts superior to other production techniques if treated properly. It should be possible to produce parts that handle forces in unique ways such that machining, molding, sintering, and other commonly implemented methods will have a hard time competing with in many applications.

Re-envisioning the slicer is no small task, so I’m going to tackle it in three articles. Part One, here, will cover the improvements yet to be had with the 2D and layer height model of slicing. It is the first and most accessible avenue for improvement in slicing technologies. It will require new software to be written but does not dramatically affect the current construction of 3D printers today. It should translate to every printer currently operating without even a firmware change.

Part Two will involve making mechanical changes to the printer: multiple materials, temperatures, and nozzle sizes at least. The slicer will need to work with the printer’s new capabilities to take full advantage of them.

Finally, in Part Three, we’ll consider adding more axes. A five axis 3D printer with advanced software, differing nozzle geometries, and multi material capabilities will be able to produce parts of significantly reduced weight while incorporating internal features exceeding our current composites in many ways. Five axis paths begin to allow for weaving techniques and advanced “grain” in the layers put down by the 3D printer.

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Mythical Game Boy Advance Colors Hacked Into Reality

September 15, 2015 by Brian Benchoff 6 Comments

When it was announced in 2000 at a Nintendo trade show, the Game Boy Advance was clad in beautiful silver plastic, accented with brilliant orange buttons. As is usually the case with product introductions, the first color and style displayed to be public became the most popular. There was one problem with this silver and orange GBA; Nintendo never put it into production. Fast forward fifteen years, and [Michael Choi] decided it was time to make his own silver and orange Game Boy. It’s a great introduction to mold making and very detailed painting, and a useful guide for turning engineering prototypes into beautiful objects.

[Michael]’s build began with an aftermarket shell, painted with Tamiya spray paints. The color is remarkably accurate, considering the only pictures for the silver and orange Game Boy are fifteen years old, and with the right painting technique, these colors are indistinguishable from a properly colored, injection molded piece of plastic.

The buttons were not as easy as the shell. [Michael] originally decided casting would be the best solution, but after multiple attempts, he couldn’t get the color right. Even with opaque dyes in the resin, the buttons would still come out slightly translucent. In the end, [Michael] decided to paint the original buttons.

This casemod isn’t just about changing the color of the enclosure. [Michael] also wanted is Game Boy to have the backlight found in the second revision clamshell GBA. This was easily acquired on eBay, and with a few slight hardware modifications and a beautiful glass lens to replace the plastic occupying the bezel, [Michael] has a gorgeous Game Boy Advance, taken straight from a press event fifteen years ago.

“Arduino Borealis” Combines LEDs And Paint

August 6, 2015 by Rick Osgood 6 Comments

[Stef Cohen] decided to combine three different artistic mediums for her latest project. Those are painting, electronics, and software. The end goal was to recreate the aurora borealis, also known as the northern lights, in a painting.

The first step was to make the painting. [Stef] began with a shadow box. A shadow box is sort of like a picture frame that is extra deep. A snowy scene was painted directly onto the front side of the glass plate of the shadow box using acrylic paint. [Stef] painted the white, snowy ground along with some pine trees. The sky was left unpainted, in order to allow light to shine through from inside of the shadow box. A sheet of vellum paper was fixed to the inside of the glass pane. This serves to diffuse the light from the LEDs that would eventually be placed inside the box.

Next it was time to install the electronics. [Stef] used an off-the-shelf RGB LED matrix from Adafruit. The matrix is configured with 16 rows of 32 LEDs each. This was controlled with an Arduino Uno. The LED matrix was mounted inside the shadow box, behind the vellum paper. The Arduino code was easily written using Adafruit’s RGB Matrix Panel library.

To get the aurora effect just right, [Stef] used a clever trick. She took real world photographs of the aurora and pixelated them using Photoshop. She could then sample the color of each pixel to ensure that each LED was the appropriate color. Various functions from the Adafruit library were used to digitally paint the aurora into the LED matrix. Some subtle animations were also included to give it an extra kick.

Fail Of The Week: Silicone Molding That Won’t Cure

February 13, 2014 by Mike Szczys 60 Comments

fotw-uncured-silicone

Mold making is a hacking skill we see pop up around here from time to time. But rarely do we hear about problems in the process, and they must happen. Here’s proof. This Fail of the Week focuses on [Michael’s] unfortunate experience with failed mold making due to uncured silicone around the master mold. It’s worse than it may sound, since he lost about a pound of silicone to the fail, and we’re unsure of whether he can even use the master again (how do you clean uncured silicone off of something?). Not to mention the time lost from setting up the pour and waiting 20 hours for it to cure.

Soon after the issue presented itself [Michael] started researching to see what had gone awry and noticed that the master should have been sealed with acrylic lacquer. This gave him the opportunity to test several different finishes before making a run at the full mold once again. He picked up a variety of the paint products he could find locally, used them to coat some scraps, and globbed on some silicone to see which worked the best. He found a couple of different primers worked well, as did both glossy and matte acrylic coatings.

If you’ve never had a reason for mold making before, keep it in mind. You’d be surprised what kind of factory-production-type things can be pulled off by 3D printing a master, and casting a silicone mold of it.

Fail of the Week is a Hackaday column which runs every Wednesday. Help keep the fun rolling by writing about your past failures and sending us a link to the story — or sending in links to fail write ups you find in your Internet travels.