Stop Silicone Cure Inhibition, No Fancy Or Expensive Products Required

Casting parts in silicone is great, and 3D printing in resin is fantastic for making clean shapes, so it’s natural for an enterprising hacker to want to put the two together: 3D print the mold, pour in the silicone, receive parts! But silicone’s curing process can be inhibited by impurities. What’s cure inhibition? It’s a gross mess as shown in the image above, that’s what it is. Sadly, SLA-printed resin molds are notorious for causing exactly that. What’s a hacker to do?

Firstly: there are tin-cure and platinum-cure silicones, and for the most part tin-cure silicone works just fine in resin-printed molds. Platinum-cure silicones have better properties, but are much more susceptible to cure inhibition. Most workarounds rely on adding some kind of barrier coating to molds, but [Jan Mr├ízek] has a cheap and scalable method of avoiding this issue that we haven’t seen before. Continue reading “Stop Silicone Cure Inhibition, No Fancy Or Expensive Products Required”

laser cut acrylic coaster with rgb leds inside

Your Mug Will Like This Glowy Coaster

[Charlyn] wanted to highlight their friends beautiful mug collection, so the Glowy Coaster was born.

The coaster is made up of six layers of laser cut acrylic. The top and bottom layer are cut out of clear acrylic, providing a flat surface for the coaster. A top pattern layer made of pearl acrylic has a thin piece of vellum put underneath it to provide diffusion for the LED strip sandwiched inside. The middle layers are made of peach acrylic and have their centers hollowed out to provide room for the electronics inside. The top pearl acrylic layer gives the coaster, as [Charlyn] writes, a “subtle touch of elegance”. The coaster itself is screwed together by an M3 screw at each point of the hexagon that feed through to heat-set inserts.

inside of glowy coaster with electronics exposed

The electronics consist of a short NeoPixel strip, cut to include 12 LEDs pointed in towards the center of the coaster. The LEDs are driven by a Trinket M0 microcontroller with a LiPo “backpack” to provide power, attachment points for the exposed power switch and recharging capability to the 110 mAh 3.7 V battery. The code is a slightly modified NeoPixel “rainbow” wheel loop (source available as a gist). The design files are available through Thingiverse.

Creations like these highlight how much care and work goes into a project with minimal beauty, where decisions, like the opacity and thickness of the acrylic or countersinking the M3 screws, can have huge consequences for the overall aesthetic. [Charlyn] has an attention to detail that brings an extra touch of professionalism and polish to the project.

Coasters are a favorite for laser cutting and we’ve covered many different types, including
coaster bots, coaster engravers and even a color changing, drink sensing coasters.

Continue reading “Your Mug Will Like This Glowy Coaster”

DIY Retrograde Clock Is 3D Printed

Retrograde clocks are unique, in that they eschew the normal fully-circular movement for the hands. Instead, the hands merely sweep out a segment of a circular arc, before jumping back to their start position to begin again. They’re pretty rare to find, but [Jamie Matthews] decided he had to have one. Thusly, he elected to build his own!

For his build, [Jamie] started with a regular off-the-shelf clock movement you might find in any hobbyist clock build. From there, he affixed his own witches’ brew of racks and gears to the output in order to create the desired semi-circular mechanism. The arcane mechanism enables the clock to tell time over roughly a 180-degree arc.

It’s relatively simple to make one of your own, too. The parts are all readily 3D printable, with [Jamie] reporting it took less than 8 meters of filament to produce the geartrain for his build. You can even print the clock face if you don’t want to CNC cut it out of acrylic.

Overall, it’s a fun look at an often-forgotten part of our horological history. Desktop 3D printing really does enable the creation of some exciting, different clock designs. Video after the break.

Continue reading “DIY Retrograde Clock Is 3D Printed”

Hackaday Prize 2022: Upcycling Acrylic Scraps

Living and working in a remote rain forest may sound idyllic to those currently stuck in bland suburbia, and to be sure it does have plenty of perks. One of the downsides, though, is getting new materials and equipment to that remote location. For that reason, [Digital Naturalism Laboratories], also known as [Dinalab], has to reuse or recycle as much as they can, including their scraps of acrylic leftover from their laser cutter.

The process might seem straightforward, but getting it to actually work and not burn the acrylic took more than a few tries. Acrylic isn’t as thermoplastic as other plastics so it is much harder to work with, and it took some refining of the process. But once the details were ironed out, essentially the acrylic scraps are gently heated between two steel plates (they use a sandwich press) and then squeezed with a jack until they stick back together in one cohesive sheet. The key to this process is to heat it and press it for a long time, typically a half hour or more.

With this process finally sorted, [Dinalab] can make much more use of their available resources thanks to recycling a material that most of us would end up tossing out. It also helps to keep waste out of the landfill that would otherwise exist in the environment indefinitely. And, if this seems familiar to you, it’s because this same lab has already perfected methods to recycle other types of plastic as well.

Continue reading “Hackaday Prize 2022: Upcycling Acrylic Scraps”

Transparent Framedeck Is Clearly Capable

When the universe tells you to build a cyberdeck, then build a cyberdeck you must. The lucky [Richard Sutherland] got an email from user-serviceable laptop purveyors Framework about the availability of their main board for use as a single-board computer. They agreed to send him a laptop and some extra modules as long as he promised to build something awesome with it. There was just one fabulous caveat: whatever design he came up with had to be released to the public.

[Richard] took this capable board with four USB ports and built an all-in-one that pays homage to the slab-style computers like the TRS-80 Model 100, which [Richard] really wanted as a kid. It looks lovely in layered acrylic and brass, and even though we pretty much always think that see-through is the best design choice you can make, transparency really works here. Tucked into those layers is a custom 36-key split running on an Elite-C microcontroller with Gazzew Boba U4 Silent-but-tactile switches, and a trackball in between. Be sure to take the build tour and check out all the process pictures.

Acrylic looks great and seems great on paper, but what about actual use? [Richard] put rubbery SKUF feet on the front, and a pair of repositionable feet on the back. Not only will it stay in place on the table, but he’ll be able to see the screen better and type at an angle greater than zero.

As cool as it would be to have Framedeck in the apocalypse, it will be hard to hide and could get looted. You might want to build something a bit more concealed.

Building An Edge Lit Sign From The Scrap Pile

Whether in a shop window or mounted to the top of consoles in NASA’s Mission Control Center, edge lit acrylic is a popular choice for making high visibility signs. Partly because of their striking hologram-like appearance, but also because they’re exceptionally cheap and easy to produce. Just how cheap and easy? Take a look at this recent video from [Hack Modular] for a perfect example.

Now you might think you’d need something like a CNC router to produce a sign like this, and for more complex images, that’s arguably the case. But if you’re only concerned with text, and have a fairly steady hand, you can pull off the etching step with nothing more exotic than a printed template and a razor blade. Of course, the LCD style font that [Hack Modular] picked for this sign is particularly well suited to hand cutting — if you’re interested in edge lit calligraphy, this method probably isn’t what you’re looking for.

This linear LED provides a more consistent light.

With the text carved into the acrylic, the only missing ingredient is light. For that, [Hack Modular] is using a 12 volt linear LED strip light. That is, instead of being dotted with individual LEDs like traditional strips, it provides a continuous band of light that’s perfect for this application. That gets stuck down to a scrap piece of wood, and a rusty angle bracket from an old Meccano set is used to hold the acrylic right on the center-line. If you think the final product looks like something that was created from trash, don’t feel bad, that was the intent.

The end result looks great. In fact, if we’re being honest, it’s a lot better than we would have thought was possible using hand tools. Granted the choice of font has a lot to do with that, but then again, we wouldn’t mind if all our edge lit acrylic signs ended up looking like big seven-segment displays either.

Continue reading “Building An Edge Lit Sign From The Scrap Pile”

fiber matrix

Big LED Matrix Becomes Tiny LED Matrix Thanks To Fiber Optics

Everyone loves LED matrices, and even if you can’t find what you like commercially, it’s pretty easy to make just what you want. Need it big? No problem; just order a big PCB and some WS2812s. Need something tiny? There are ridiculously small LEDs that will test your SMD skills, as well as your vision.

But what if you want a small matrix that’s actually a big matrix in disguise? For that, you’ll want to follow [elliotmade]’s lead and incorporate fiber optics into your LED matrix. The build starts with a 16×16 matrix of WS2812B addressable LEDs, with fairly tight spacing but still 160 mm on a side. The flexible matrix was sandwiched between a metal backing plate and a plastic bezel with holes directly over each LED. Each hole accepts one end of a generous length of flexible 1.5-mm acrylic light pipe material; the other end plugs into a block of aluminum with a 35 by 7 matrix of similar holes. The small block is supported above the baseplate by standoffs, but it looks like the graceful bundle of fibers is holding up the smaller display.

A Raspberry Pi Pico running a CircutPython program does the job of controlling the LEDs, and as you can see in the video below, the effect is quite lovely. Just enough light leaks out from the fibers to make a fascinating show in the background while the small display does its thing. We’ve seen a few practical uses for such a thing, but we’re OK with this just being pretty. It does give one ideas about adding fiber optics to circuit sculptures, though.

Continue reading “Big LED Matrix Becomes Tiny LED Matrix Thanks To Fiber Optics”