A Six-year Adventure Into The World Of CNC Fabrication

April 11, 2012 by Brian Benchoff 51 Comments

Hackaday doesn’t always get the entire back story of a build. The usual assumption is that someone decided to build something, and with just a little bit of effort the project makes it into the Hackaday tip line. This doesn’t do justice to the builder, with skills honed after years of practice and experience. A 200-word summary is deceiving, and makes everything look almost too easy. [Michal] decided to buck that trend and sent in his half-decade long adventure of becoming one of the best micro-scale machinists we’ve ever seen.

In 2006, with years of robots made out of hot glue and cardboard behind him, and the quality of 3D printers not up to his exacting specifications, [Michal] snapped. He sunk the better part of $3000 into a Roland MDX-15 desktop mill. After several months of futzing about with acrylic sheet, [Michal] came across the wonderful machining properties of modeling board.

Determined to do something useful with this modeling board, [Michal] started looking into resin casting. Casting in resin is a common technique in the artist and model maker communities to mass produce small plastic parts. After getting his hands on eight liters of polyurethane resin, [Michal] made a useful part guiding the direction his skill set would grow in the coming years.

After years of experimenting with techniques, materials, and mediums, [Michal] eventually honed his craft and was able to finally start building real robots. These projects were a far cry from the cardboard and milk jug contraptions made earlier in his career. [Michal] was now producing incredibly precise gear assemblies with accuracies within 0.002 mm.

You may remember [Michal] from his robot with pivoting wheels we showcased last week. He got a lot of email from people wanting to know how to start delving into his unique blend of artistry, engineering, and craftsmanship. The good news is you can now learn from his mistakes, so a planetary gearbox shouldn’t take more than a few months to finish.

Who Needs Mecanum Wheels?

April 3, 2012 by Mike Szczys 36 Comments

Skills are all that’s needed to solve a problem. Take this four-wheeled robot as an example. [Michal Zalewski] wanted it to be omnidirectional but wasn’t very satisfied with the concept of mecanum wheels and the like. So he designed a chassis with wheels at each corner that can pivot as one to change orientation. The image may look like a rendering at first glance, but this is actually the physical prototype. See what we mean about skills?

Okay, so the robot design is pretty cool. But we’re more excited about the build process. We’ve looked at [Michal’s] work before. He wrote a thorough guide about CNC mold making. These parts are all cast from epoxy. This starts with a rough milled mold, which is given a second pass for the fine details before being painted with a release agent and used to make a silicone mold. From this the parts are produced. Check out the Flickr set showing the casting process for the planetary gear box on each motor. If only these results were as easy to achieve as he makes it look.

[via Reddit]

Color Changing Door Handles

August 10, 2011 by Mike Szczys 22 Comments

This color changing door handle was made using a very simple manufacturing process. [Barmak] already had experience working with polyester resins when making passive component filled drawer pulls (he included a couple of pictures at the end of his post). The same process was used here except that instead making it from one solid chunk of clear resin he decided to use alternating layers of dyed resin.

The build begins with a mold made out of MDF. This material has a very smooth surface finish which will help with the final look of the door handle. Threaded rod is inserted through carefully placed holes in the side of the mold — these will serve as the mounting hardware when complete. He then pours thin coats of resin to build up the complete handle.

An RGB LED strip is incorporated in the side of the handle that will go toward the door. It seems like the wires to control the device pass through a hollow spacer surrounding the threaded rod. He makes some mention of using a 555 timer to control the colors, but there’s not much more information than that. Still, the reflected light is a unique feature if you’ve got a place in your home that needs to be spiced up.

Once you’re done, you can use any leftover resin to make your own project boxes.

Devil Horns Adorn The Hood Of My Truck

June 1, 2011 by Mike Szczys 31 Comments

When you’re hunting zombies you’ve got to give them something to fear. [Shannon Larratt] is getting ready for that eventuality by adding devil horns as his hood ornament. It looks awesome from afar, but when you see the close-up images you realize how lifelike this is. That’s because it’s not a sculpture. [Shannon] cast the ornament in a mold made from his own hand.

The process started with some dental alginate which he slobbered all over his hand as he held the devil horns pose. After the mold had hardened he cast the ornament using fast-curing black plastic resin.

With the ornament now in hand he needed a way to secure it to the hood of his vehicle. He picked up a threaded U-bolt. A hole and a slot were carved in the base of the ornament to receive the U-bold and a straight bolt for a trio of anchor points. More of the black resin fills the holes, securing the bolts and making it a snap to mount the ornament by drilling through the hood.

We also find it awesome that during this process [Shannon] took the time to cast his daughter’s fist for use as a door knob at home.

3D Printer Gets A Big Resolution Improvement

April 1, 2011 by Mike Szczys 48 Comments

[Jose Carlos Veloso Junior] has been working on his 3D printer to improve the resolution. We looked in on his project back in October when he was printing the blue busts like the one seen above.

We were impressed by the resolution he was able to achieve back then, using liquid resin that is cured with visible light. The resin creates a thin layer on a glass tray, and is cured when a projector shines precisely positioned light from below. The cured resin is then lifted on the Z-axis, and the next layer in the printing process is hardened by the projector’s light.

Well, this newest rendition far outperforms the initial iteration. The bust on the right looks like it’s been hand-buffed to remove the layer lines, but it actually just came off of the printer. [Jose] made a video of the new equipment in action, which you can watch after the break. He’s keeping most of the juicy bits to himself but he did tell us that the improvement he achieved were due to multiple changes in the process. He tweaked the software to use a more precise curing time, the resin formula has been improved, the ability to isolate pixels without hardening resin around them has been stepped up, and he’s made changes to the way the printer is calibrated and how it lifts the hardened model.

This is fantastic. Kudos to you sir!

Continue reading “3D Printer Gets A Big Resolution Improvement” →

3D Printing With Visible Light

October 15, 2010 by Mike Szczys 14 Comments

This 3D printer manages some pretty fantastic resolution, and these are just the early results of [Junior Veloso’s] build. He put together a machine that prints objects in resin that cures in visible light. To print, a thin layer of raw liquid resin self-levels across a printing surface and a DLP-based projector shines light from below, onto the portion to be hardened. The z-axis then pulls that layer up and the next to be printed will become the newest bottom layer. Horizontally the printer yields 1024×768 resolution with a layer thickness as small as 0.01 mm. No wonder he’s turning out this kind of quality.

The model above took 5 hours to print, with eight-second exposure for each layer, and 0.1mm layer thickness. There is lots of good information on his blog, from the early planning, to the finished hardware so take some time to learn about this fascinating project.

Update: Thanks to reader [Nave.notnilc] for pointing out that we’ve seen a chemical 3D printing technique before.

Daft Punk Replica Helmet

October 13, 2009 by Phil Burgess 12 Comments

daftpunkhelmet

For all their varied and entertaining uses, circuits and code comprise only part of the complete hacking experience. To really put your project over the top, sooner or later you’ll want to possess some physical fabrication skills. Consider the works of [Ben Heckendorn]: He’s always done a fantastic job with the electronics, but it’s the fit and finish of the enclosures that make him a legend.

“Fabrication” usually conjures images of shop tools — saws and sanders and drills — all tremendously useful skills worth learning, and easily within reach of most home shops or garages. Recently, the techniques of mold making and casting have seen something of a DIY renaissance. Mold making is nothing new, the basic concepts go back millennia, but in just the past few years the materials for extremely high-quality molds have become safer, simpler to use, and easier to acquire.

This being Halloween month, what better example of the medium than this impeccable replica helmet styled after half of the musical duo Daft Punk (a recurring theme among Hack a Day contributors), created by prop maker [Harrison Krix]. After sculpting an original master part (from common hardware store and art store materials, we might add), a one-piece flexible mold is built up from silicone, which captures every minute detail, and later the helmet form is cast from a thin layer of resin. The visor is vacuum formed. A follow-up with the internal electronics build is yet to be posted, but even at this stage the shell alone is so refined it looks straight off a showroom floor. If mold making can do this for someone’s noggin, imagine what it can do for your next creative hardware project. Smooth-On, a major supplier of these materials, has a free PDF introduction and a set of tutorials on their web site.

[thanks Wolf]