If you want a big CNC machine you need a strong, vibration-resistant base. They build bells out of metal, so that might not be the best if you want something that doesn’t shake. Epoxy granite is your best bet, but what epoxy granite is the best? That’s the question [Adam Bender] answered in a series of experiments that resulted in a great-looking CNC machine.
While this is a project that resulted in a completed base for a CNC machine, this is also an experiment to determine the best formula for creating your own epoxy granite. The purpose of the experiment is effectively to determine the best-looking epoxy granite and uses four variables in the composition of this composite. Play sand, gravel, dye (in the form of iron oxide and liquid epoxy dye), and two-part epoxy were used to create seven different samples. Samples using rock didn’t turn out that great and still had trapped air. This was true even if the epoxy was put in a vacuum chamber for degassing. The winning combination turned out to be a mix of 80% sand and 20% epoxy with a bit of black dye, vibrated for 30 minutes on a DIY shaker table.
With the correct formula for epoxy granite, [Adam] set up his mold and waxed everything liberally. The internal skeleton, or what the CNC machine will be bolted to, is assembled inside the mold and the epoxy is poured in. The result is fantastic, and an excellent base for a machine that turns metal into chips. You can check out the video below.
The build is one that could be readily achieved in any decently equipped makerspace. [John] used lasercut steel parts to construct the molds for the epoxy base, with some custom turned parts as well. The precision cut parts fit together with great accuracy, and with proper control of the casting process there is minimal post-processing of the final cast piece required. The mold is built with zero draft angle, and is designed to be taken apart to remove the finished pieces. By using steel, the same mold can be used many times, though [John] notes that MDF could be used for a one-off build.
The base is cast in epoxy, mixed with granite aggregate and sand to create a strong, heavy, and vibration damping material. There are also steel reinforcements cast in place consisting of threaded rods, and conduits for various electrical connections. After casting, [John] has spent much time measuring and truing up the mill to ensure the best possible results from the outset.
The keyboard and mouse are great, we’re big fans. But for some tasks, such as seeking around in audio and video files, a rotary encoder is a more intuitive way to get the job done. [VincentMakes] liked the idea of having a knob he could turn to adjust his system volume or move forward and backwards through a stream in VLC, but he also wanted to be able to repeatedly enter keyboard commands with it; something commercial offerings apparently weren’t able to do.
So he decided to build his own USB knob that not only looks fantastic, but offers the features he couldn’t find anywhere else. It’s another project which proves that DIY projects don’t have to look DIY. In fact, they can often give their commercial counterparts a run for their money. But this “Infinity USB Knob” isn’t just a pretty face, it allows the user to do some very interesting things such as quickly undo and redo changes to see how they compare.
As you might imagine, the electronics for this project aren’t terribly complex. The main components are the Adafruit Trinket M0 microcontroller and the EC11 rotary encoder itself. To provide nice visual feedback he added in a NeoPixel ring, but that’s not strictly necessary if you’re trying to rig this up yourself. Though we have to say the lighting effects are a big part of what makes this build look so good.
Though certainly not the only part. The aluminum enclosure, combined with the home theater style knob on the encoder, really give the finished product a professional look. We especially like his method of drilling out the top of the case and filling in the holes with epoxy to create easy and durable LED diffusers. Something to keep in mind for your next control panel build, perhaps.
[VincentMakes] has done an excellent job of documenting the hardware and software sides of this build on Hackaday.io, and gives the reader enough information that replicating this project should be pretty straightforward for anyone who’s interested. While we’ve seen several rotary encoder peripherals for the computer in the past, we have to admit this is one of the most compelling yet from a visual and usability standpoint. If this build doesn’t make you consider adding a USB knob to your arsenal, nothing will.
[Black Beard Projects] sealed some pine cones in colored resin, then cut them in half and polished them up. The results look great, but what’s really good about this project is that it clearly demonstrates the necessary steps and techniques from beginning to end. He even employs some homemade equipment, to boot.
Briefly, the process is to first bake the pine cones to remove any moisture. Then they get coated in a heat-activated resin for stabilizing, which is a process that infuses and pre-seals the pine cones for better casting results. The prepped pine cones go into molds, clear resin is mixed with coloring and poured in. The resin cures inside a pressure chamber, which helps ensure that it gets into every nook and cranny while also causing any small air bubbles introduced during mixing and pouring to shrink so small that they can’t really be seen. After that is cutting, then sanding and polishing. It’s an excellent overview of the entire process.
The video (which is embedded below) also has an outstanding depth of information in the details section. Not only is there an overview of the process and links to related information, but there’s a complete time-coded index to every action taken in the entire video. Now that’s some attention to detail.
Word clocks use natural language to display the time. They’ve been in vogue in the last 20 years or so, as low-cost digital technology makes them particularly cost effective and easy to build for the average maker. The hardware and software is a solved problem, so presentation is everything. Luckily, [watsaig]’s effort does not disappoint.
The build began with a timeframe of just seven days — a narrow window given [watsaig]’s lack of experience with lasercutting and woodworking. Not content to let that get in the way, it was time to get to work. Wood was sourced from Amazon and designs laid out, before lasercutting began in earnest.
[watsaig] decided to fill all of the letters with epoxy to achieve a flat finished surface that also served as diffuser for the LEDs. To avoid using an unsightly stencil font, the centers (the cut out portion) of letters like O, A, and R had to be placed by hand. Unfortunately his turned out quite badly. When using a squeegee method to work epoxy into the letters, the inserts tended to shift, ruining the face plate.
Undeterred, the clock face was recreated from scratch, and it was determined that a pipette was a far more suitable tool, allowing the letters to be filled with epoxy without unduly disturbing the letter inserts. The final result is visually attractive, finished with a wonderful stain and giving a pleasing glow thanks the careful attention to diffusion and masking. The hidden Happy Birthday message may have been lost in the rush, but it’s the thought that counts, after all.
The world of glues is wide and varied, and it pays to use the right glue for the job. When [Eric] needed to stick a wide and flat 3D printed mount onto the back of a PCB that had been weatherproofed with an uneven epoxy coating, he needed a gap-filling adhesive that would bond to both surfaces. It seemed like a job for the hot glue gun, but the surface was a bit larger than [Eric] was comfortable using with hot glue for. The larger the surface to be glued, the harder it is to do the whole thing before hot glue cools too much to bond properly.
What [Eric] really wanted to use was a high quality two-part epoxy that he already had on hand, but the stuff was too runny to work properly for this application. His solution was to thicken it with a thixotropic filler, which yields a mixture that is akin to peanut butter: sticky, easily spread to where it’s needed, but otherwise stays in place without dripping or sagging and doesn’t affect bonding.
Common thixotropic fillers include ground silica or plastic fibers, but [Eric]’s choice was wood flour. Wood flour is really just very fine sawdust, and easily obtained from the bag on his orbital sander. Simply mix up a batch of thin two-part epoxy and stir in some wood flour until the sticky mixture holds its shape. Apply as needed, and allow it to cure.
Thanks to this, [Eric] was able to securely glue a 3D printed pad to the back of his animated LED snowflakes to help mount them in tricky spots. Whether for small projects or huge installations, LEDs, PCBs, and snowflakes are a good combination.
For most of human history, our inventions and innovations have been at a scale that’s literally easy to grasp. From the largest cathedral to the finest pocket watch, everything that went into our constructions has been something we could see with our own eyes and manipulate with our hands. But in the middle of the 20th century, we started making really, really small stuff: semiconductors. For the first time, we were able to create mechanisms too small to be seen with the naked eye, and too fine to handle with our comparatively huge hands. We needed a way to scale these devices up somewhat to make them useful parts. In short, they needed to be packaged.
We know that the first commercially important integrated circuits were packaged in the now-familiar dual in-line package (DIP), the little black plastic millipedes that would crawl across circuit boards for the next 50 years. As useful and versatile as the DIP was, and for as successful as the package became, its design was anything but obvious. Let’s take a look at the dual in-line package and how it got that way.