3D Printed Machine Shows How Braiding Is Done

If there’s something more fascinating than watching cleverly engineered industrial machines do their work, we don’t know what it could be. And at the top of that list has to be the machines that do braiding. You’ve probably seen them, with spools of thread or wire dancing under and around each other in an endless ballet that somehow manages to weave a perfect braid. It’s kind of magical.

For those who haven’t seen such a thing, now’s your chance, with this twelve-spool braiding machine. The building methods that [Fraens] used — mainly 3D printing and laser-cut acrylic — make the workings on this machine plain, even to those of us who never learned to manually braid even three strands. It’s far easier to understand by watching the video below than by trying to describe it, but basically, each vertical supply spool runs along a continuous track around a central point by a series of six meshed gears, passing under each other as they progress around the carousel and forming the braid.

There are a ton of details that go into making this work. Chief among them is the thread tensioning mechanism, which is a lever arm and spring-loaded axle that lives at the very center of each spool. The gears that form the inside-outside tracks are quite clever too, as are the worm-gear-driven takeup reel and output tensioner. We also appreciated the gate used to load the spool carriers into the track.

We can recall a couple of braiding machines before, including this one made entirely from Lego Technics.

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Polar Platform Spins Out Intricate String Art Portraits

We have semi-fond memories of string art from our grade school art class days. We recall liking the part where we all banged nails into a board, but that bit with wrapping the thread around the nails got a bit tedious. This CNC string art machine elevates the art form far above the grammar school level without all the tedium.

Inspired by a string art maker we recently feature, [Bart Dring] decided to tackle the problem without using an industrial robot to dispense the thread. Using design elements from his recent coaster-creating polar plotter, he built a large, rotating platform flanked by a thread handling mechanism. The platform rotates the circular “canvas” for the portrait, ringed with closely spaced nails, following G-code generated offline. A combination of in and out motion of the arm and slight rotation of the platform wraps the thread around each nail, while rotating the platform pays the thread out to the next nail. Angled nails cause the thread to find its own level naturally, so no Z-axis is needed. The video below shows a brief glimpse of an additional tool that seems to coax the threads down, too. Mercifully, [Bart] included a second fixture to drill the hundreds of angled holes needed; the nails appear to be inserted manually, but we can think of a few fixes for that.

We really like this machine, both in terms of [Bart]’s usual high build-quality standards and for the unique art it creates. He mentions several upgrades before he releases the build files, but we think it’s pretty amazing as is.

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Homebrew Attachment Turns Angle Grinder Into Slimline Belt Sander

If there’s a small power tool as hackable as the angle grinder, we haven’t found it yet. These versatile tools put a lot of power in the palm of your hand, and even unhacked they have a huge range of functionality, from cutting to grinding to polishing and cleaning, just by choice of what goes on the arbor.

With a simple homebrew attachment, [Darek] turned his angle grinder into a micro-belt sander that’s great for those hard-to-reach places. The attachment that clamps where the disc guard normally lives adds a drive roller to the grinder’s arbor; idler rollers ride on the end of a small pneumatic spring that keeps the belt under tension. The belts themselves are cut down from wider sanding belts, and the attachment can take belts of various widths. And best of all, he did it all without any fancy machine tools. No lathe? No problem – the drive roller was ground to the proper crowned profile needed to keep belts centered using the angle grinder itself. The only problem we see is that the attachment can’t be easily removed from the grinder, but that’s OK. Grinders are like potato chips, after all – you can’t stop at one.

This isn’t [Darek]’s first angle grinder hacking rodeo, of course. And if you’re looking for inspiration on how to hack yours, look no further: a floor sander, a precision surface grinder, or even an e-bike can be built.

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