The Kilopixel Display

August 9, 2025 by Jenny List 6 Comments

Despite the availability of ready-made displays never being better, there are still some hardy experimenters who take on the challenge of making their own. In [Ben Holmen]’s case the display he built is somewhat unusual and not the most practical, but for us a giant-sized wooden kilopixel display is exactly what the world needs.

It’s a kilopixel display because it has a resolution of 40 by 25 pixels, and it takes the form of a rack of wooden cubes, each of which can be turned by a tool on a gantry to expose either a black or a white side. It’s very slow indeed — he has an over nine hour long video of it in operation — but it is an effective device.

His write-up goes into great detail about the steps taken in its design, starting with spherical pixels rotated by a LEGO wheel and progressing to cubes poked at their corner to rotate. The pusher in this case is a hot glue stick, for the required flexibility. For practicality we’re reminded of this serial oil-and-water display.

The whole thing is online, and if you want you can submit your own images for it to draw. Whether a Wrencher in 25 pixel resolution has enough detail, we’ll leave to you.

The LumenPnP Pasting Utility: Never Buy Solder Stencils Again?

July 30, 2025 by John Elliot V 11 Comments

Over on his YouTube channel the vivacious [Stephen Hawes] tells us that we never need to buy solder stencils again!

A big claim! And he is quick to admit that his printed solder paste isn’t presently quite as precise as solder stencils, but he is reporting good success with his technique so far.

[Stephen] found that he could print PCBs with his fiber laser, populate his boards with his LumenPnP, and reflow with his oven, but… what about paste? [Stephen] tried making stencils, and in his words: “it sucked!” So he asked himself: what if he didn’t need a stencil? He built a Gerber processing, G-code generating, machine-vision implemented… website. The LumenPnP Pasting Utility: https://paste.opulo.io/

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Skateboard Wheels Add Capabilities To Plasma Cutter

July 28, 2025 by Bryan Cockfield 4 Comments

Although firmly entrenched in the cultural zeitgeist now, the skateboard wasn’t always a staple of popular culture. It had a pretty rocky start as surfers jankily attached roller skating hardware to wooden planks searching for wave-riding experiences on land. From those rough beginnings it still took decades of innovation until Rodney Mullen adapted the ollie for flatground skating before the sport really took off. Skateboard hardware is quite elegant now too; the way leaning turns the board due to the shape of the trucks is immediately intuitive for even the most beginner riders, and bearing technology is so high-quality and inexpensive now that skateboard hardware is a go-to parts bin grab for plenty of other projects like this plasma cutter modification.

[The Fabrication Series]’s plasma cutter is mounted to a CNC machine, allowing for many complex cuts in much less time than it would take to do by hand. But cutting tubes is a more complicated endeavor for a machine like this. This is where the skateboard hardware comes in: by fabricating two custom pivoting arms each with two skateboard wheels that push down on a tube to hold it in place, the CNC machine can roll the tube along the table in a precise way as the plasma cutter works through it.

Of course, cutting a moving part is a little more complicated for the CNC machine than cutting a fixed piece of sheet metal, so [The Fabrication Series] walks us through a few ways of cutting pipe for various purposes, including miters and notches. The first step is to build a model of the pipes, in this case using Onshape, and then converting the 3D model of the pipes into a sheet metal model that the CNC machine can use. It does take a few cuts on the machine to fine-tune the cuts, but in no time the machine is effortlessly cutting complex shapes into the pipe. Don’t have a plasma cutter at all? You can always build your own from scratch.

Thanks to [JohnU] and [paulvdh] for the tip!

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Engrave A Cylinder Without A Rotary Attachment? No Problem!

July 26, 2025 by Donald Papp 3 Comments

Laser-engraving a cylindrical object usually requires a rotary attachment, which is a motorized holder that rotates a cylindrical object in sync with the engraver. But [Samcraft] shows that engraving all around a mug can be done without a motorized rotary holder.

Separating a design into elements thin enough to engrave individually without losing focus is the key.

The basic idea is to split the design into a number of separate engraving jobs, each containing one element of the overall design, then setting the mug into a 3D printed jig and manually rotating it between jobs. To demonstrate, [Samcraft] selects a series of line-art flowers and plants which are ideal for this approach because there’s no need to minutely register the individual engravings with one another.

What about focus? [Samcraft] found that a design up to 45 mm wide could be engraved onto the curved surface of his mug before focus suffers too much. It’s true that this technique only works with certain types of designs — specifically those with individual elements that can be separated into tall and thin segments — but the results are pretty nice.

Laser engravers are a very serious potential eye hazard, and we are not delighted to see the way the shield around [Samcraft]’s engraver cannot close completely to accommodate the mug while the laser is active. But we’re going to assume [Samcraft] has appropriate precautions and eye protection in place off-camera, because laser radiation and eyeballs absolutely do not belong together, even indirectly.

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Human In The Loop: Compass CNC Redefines Workspace Limits

July 25, 2025 by Matt Varian 15 Comments

CNCs come in many forms, including mills, 3D printers, lasers, and plotters, but one challenge seems universal: there’s always a project slightly too large for your machine’s work envelope. The Compass CNC addresses this limitation by incorporating the operator as part of the gantry system.

The Compass CNC features a compact core-XY gantry that moves the router only a few inches in each direction, along with Z-axis control to set the router’s depth. However, a work envelope of just a few inches would be highly restrictive. The innovation of the Compass CNC lies in its reliance on the operator to handle gross positioning of the gantry over the workpiece, while the machine manages the precise, detailed movements required for cutting.

Most of the Compass CNC is constructed from 3D printed parts, with a commercial router performing the cutting. A Teensy 4.1 serves as the control unit, managing the gantry motors, and a circular screen provides instructions to guide the operator on where to position the tool.

Those familiar with CNC routers may notice similarities to the Shaper Origin. However, key differences set the Compass CNC apart. Primarily, it is an open source project with design files freely available for those who want to build their own. Additionally, while the Shaper Origin relies on a camera system for tracking movement, the Compass CNC uses four mouse sensors to detect its position over the workpiece.

The Compass CNC is still in development, and kits containing most of the necessary components for assembly are available. We’re excited to see the innovative creations that emerge from this promising new tool.

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A photo of a Stirling Engine attached to a bike

Building A Stirling Engine Bike

July 17, 2025 by John Elliot V 27 Comments

Over on his YouTube channel [Tom Stanton] shows us how to build a Stirling Engine for a bike.

A Stirling Engine is a heat engine, powered by the expansion and contraction of a working fluid (such as air) which is heated and cooled in a cycle. In the video [Tom] begins by demonstrating the Stirling Engine with some model engines and explains the role of the displacer piston. His target power output for his bike engine is 150 watts (about 0.2 horsepower) which is enough power to cycle at about 15 mph (about 24 km/h). After considering a CPU heatsink as the cooling system he decided on water cooling instead.

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Head To Print Head: CNC Vs FDM

June 23, 2025 by Tyler August 18 Comments

It’s a question new makers often ask: “Should I start with a CNC machine or a 3D Printer?”– or, once you have both, every project gets the question “Should I use my CNC or 3D printer?” — and the answer is to both is, of course, “it depends”. In the video embedded below by [NeedItMakeIt] you can see a head-to-head comparison for one specific product he makes, CRATER, a magnetic, click-together stacking tray for tabletop gaming. (He says tabletop gaming, but we think these would be very handy in the shop, too.)

[NeedItMakeIt] takes us through the process for both FDM 3D Printing in PLA, and CNC Machining the same part in walnut. Which part is nicer is absolutely a matter of taste; we can’t imagine many wouldn’t chose the wood, but de gustibus non disputandum est–there is no accounting for taste. What there is accounting for is the materials and energy costs, which are both surprising– that walnut is cheaper than PLA for this part is actually shocking, but the amount of power needed for dust collection is something that caught us off guard, too.

Of course the process is the real key, and given that most of the video follows [NeedItMakeIt] crafting the CNC’d version of his invention, the video gives a good rundown to any newbie just how much more work is involved in getting a machined part ready for sale compared to “take it off the printer and glue in the magnets.” (It’s about 40 extra minutes, if you want to skip to the answer.) As you might expect, labour is by far the greatest cost in producing these items if you value your time, which [NeedItMakeIt] does in the spreadsheet he presents at the end.

What he does not do is provide an answer, because in the case of this part, neither CNC or 3D Printing is “better”. It’s a matter of taste– which is the great thing about DIY. We can decide for ourselves which process and which end product we prefer. “There is no accounting for taste”, de gustibus non disputandum est, is true enough that it’s been repeated since Latin was a thing. Which would you rather, in this case? CNC or 3D print? Perhaps you would rather 3D Print a CNC? Or have one machine to do it all? Let us know in the comments for that sweet, sweet engagement.

While you’re engaging, maybe drop us a tip, while we offer our thanks to [Al] for this one.

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