Array Of Useless Machines Is Useless

What’s the collective noun for a group of useless machines? A passel of useless machines? A failure? A waste? A 404?  Whatever you want to call it, [Martin Raynsford] has produced one here with this collection of 24 useless machines arranged into a 5 by 6 array. He produced it for an event at a hackerspace to amuse visitors, and it certainly seems to do the job in the video after the break.

[Martin] built the case by modifying the design of his Useless Machine kit, stretching out the case to hold multiple mechanisms. The original plan was to use a 6 by 6 matrix, but that wouldn’t fit into the laser cutter, so it ended up with 24 mechanisms in a 5 by 6 array. All of those are driven by 2 AAA batteries, and the mechanisms are efficient enough that it survived a full day of button flipping before it began to run out of juice.

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Stackable Open Source 3D Printer Enclosure

One of the unfortunate realities of desktop FDM 3D printing is that environmental factors such as ambient temperature and humidity can have a big impact on your results. Even with the exact same settings, a part that printed beautifully in the summer can warp right off the bed during the winter months. The solution is a temperature-controlled enclosure, but that can be a daunting project without some guidance. Luckily, [Jay Doscher] has spent the last few months designing a very impressive enclosure that he’s released to the community as open source.

While we’ve seen no shortage of DIY printer enclosures over the years, they tend to be fairly lightweight. But that’s not the case here. Obviously not wanting to leave anything to chance, [Jay] designed this enclosure with 2020 extrusion and aluminum side panels. You could probably sit on the thing with no ill-effects, which is good, since he also designed the enclosure to be stackable should your print farm need to expand vertically.

Of course, there’s more to this enclosure than just an aluminum box. It’s packed with features like an integrated Raspberry Pi for running Octoprint, internal and external environmental monitoring with the Adafruit SHT31-D, and a Logitech Brio 4K video camera to watch the action. While not currently implemented, [Jay] says he’s also working on an internal fire suppression system and a fan controller system which will circulate air inside the enclosure should things get a little too toasty.

The enclosure has been designed around the ever-popular Prusa i3 MK3/S, even going so far as to relocate the printer’s display to the outside so you don’t have to open the door to fiddle with the settings. But adapting it to whatever rig you happen to be running shouldn’t be a problem. Though admittedly, perhaps not as easy as adjusting an enclosure made out of metal shelving.

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Manual 3D Digitizer Works A Bit Like 3-Dimensional Measuring Tape

Digitizing an object usually means firing up a CAD program and keeping the calipers handy, or using a 3D scanner to create a point cloud representing an object’s surfaces. [Dzl] took an entirely different approach with his DIY manual 3D digitizer, a laser-cut and 3D printed assembly that uses rotary encoders to create a turntable with an articulated “probe arm” attached.

Each joint of the arm is also an encoder, and by reading the encoder values and applying a bit of trigonometry, the relative position of the arm’s tip can be known at all times. Manually moving the tip of the arm from point to point on an object therefore creates measurements of that object. [Dzl] successfully created a prototype to test the idea, and the project files are available on GitHub.

We remember the earlier version of this project and it’s great to see how it’s been updated with improvements like the addition of a turntable with an encoder. DIY 3D digitizing takes all kinds of approaches, and one example was this unit that used four Raspberry Pi Zeros and four cameras to generate high quality 3D scans.

Behold The WT-220: A ‘Clever’ VT-220 Terminal

[John Whittington] failed to win a bid for an old VT-220 serial terminal on eBay, so he decided to make his own version and improve it along the way. The result is the Whitterm-220 (or WT-220) which has at its core a Raspberry Pi and is therefore capable of more than just acting as a ‘dumb’ serial terminal.

Rear of the WT-220 with paint-filled laser engraving and all necessary connectors.

The enclosure is made from stacked panels of laser-cut plywood with an acrylic plate on the back for labels and connectors, where [John] worked paint into the label engravings before peeling off the acrylic’s protective film. By applying paint after laser-engraving but before peeling off the film, it acts as a fill and really makes the text pop.

Near the front, one layer of clear acrylic among the plywood layers acts as a light guide and serves as a power indicator, also doing double duty as TX/RX activity lights. When power is on, that layer glows, serving as an attractive indicator that doesn’t interfere with looking at the screen. When data is sent or received, a simple buffer circuit tied to the serial lines lights up LEDs to show TX or RX activity, with the ability to enable or disable this functionality by toggling a GPIO pin. A video overview is embedded below, where you can see the unit in action.

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Young Entrepreneurs Learn What Really Goes Into Making A Product

Just to be clear, the primary goal of the Papas Inventeurs (Inventor Dads) was to have the kids make something, have fun, and learn. In that light, they enjoyed a huge success. Four children designed, made, and sold laser-cut napkin rings from a booth at the Ottawa Maker Faire as a fun learning process (English translation, original link in French.) [pepelepoisson] documented the entire thing from beginning to end with plenty of photos. Things started at proof of concept, then design brainstorming, prototyping, manufacture, booth design, and finally sales. While adults were involved, every step was done by the kids themselves.

It all began when the kids were taken to a local fab lab at the École Polytechnique and made some laser-cut napkin holders from plywood for personal use. Later, they decided to design, manufacture, and sell them at the Ottawa Maker Faire. Money for the plywood came from piggy banks, 23 different designs made the cut, and a total of 103 rings were made. A display board and signs made from reclaimed materials rounded out the whole set.

In the end, about 20% of people who visited and showed interest made a purchase, and 60 of the 103 pieces were sold for a profit of $126. Of course, the whole process also involved about 100 hours of combined work between the kids and parents and use of a laser cutter, so it’s not exactly a recipe for easy wealth. But it was an incredibly enriching experience, at least figuratively, for everyone involved.

Possibly the biggest takeaway was the way manufacturing involved much more than just pressing “GO” on a laser cutter. Some pieces needed sanding after laser cutting, and each piece got two coats of varnish. If you missed it, [Bob Baddeley] showed how labor, and not materials, ends up being the most expensive part of a product.

Extreme Pi Overclocking With Mineral Oil

Liquid cooling is a popular way to get a bit of extra performance out of your computer. Usually this is done in desktops, where a special heat sink with copper tubing is glued to the CPU, and the copper tubes are plumbed to a radiator. If you want dive deeper into the world of liquid cooling, you can alternatively submerge your entire computer in a bath of mineral oil like [Timm] has done.

The computer in question here is a Raspberry Pi, and it’s being housed in a purpose-built laser cut acrylic case full of mineral oil. As a SoC, it’s easier to submerge the entire computer than it is to get a tiny liquid-cooled heat sink for the processor. While we’ve seen other builds like this before, [Timm] has taken a different approach to accessing the GPIO, USB, and other connectors through the oil bath. The ports are desoldered from the board and a purpose-built header is soldered on. From there, the wires can be routed out of the liquid and sealed off.

One other detail used here that  we haven’t seen in builds like this before was the practice of “rounding” the flat ribbon cable typically used for GPIO. Back in the days of IDE cables, it was common to cut the individual wires apart and re-bundle them into a cylindrical shape. Now that SATA is more popular this practice has been largely forgotten, but in this build [Timm] uses it to improve the mineral oil circulation and make the build easier to manage.

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SandBot Happily And Tirelessly Rolls Patterns In Sand

The patience and precision involved with drawing geometric patterns in sand is right up a robot’s alley, and demonstrating this is [rob dobson]’s SandBot, a robot that draws patterns thanks to an arm with a magnetically coupled ball.

SandBot, SCARA version. The device sits underneath a sand bed, and a magnet (seen at the very top at the end of the folded “arm”) moves a ball bearing through sand.

SandBot is not a cartesian XY design. An XY frame would need to be at least as big as the sand table itself, but a SCARA arm can be much more compact. Sandbot also makes heavy use of 3D printing and laser-cut acrylic pieces, with no need of an external frame.

[rob]’s writeup is chock full of excellent detail and illustrations, and makes an excellent read. His previous SandBot design is also worth checking out, as it contains all kinds of practical details like what size of ball bearing is best for drawing in fine sand (between 15 and 20 mm diameter, it turns out. Too small and motion is jerky as the ball catches on sand grains, and too large and there is noticeable lag in movement.) Design files for the SCARA SandBot are on GitHub but [rob] has handy links to everything in his writeup for easy reference.

Sand and robots (or any moving parts) aren’t exactly a natural combination, but that hasn’t stopped anyone. We’ve seen Clearwalker stride along the beach, and the Sand Drawing Robot lowers an appendage to carve out messages in the sand while rolling along.