A 3D Printed Marble Run Features Neat Elevator Linkage

September 21, 2022 by 20 Comments

There’s seldom anything as joyful and relaxing to watch as a simple marble run. Of course, the thing about letting marbles fall under gravity is that you eventually need to lift them back up again. The Marblevator has a mechanism that does just that.

Overall, the build features a relatively simple marble run. It consists of just six 3D printed ramps which the marble tumbles down in just a few seconds. However, the real magic is in the mechanism that restores the marbles from the bottom of the run all the way back to the top.

A motor turns a gear, which then rotates a crank leading to a multi-link rhombus. On one corner of the rhombus is a small protrusion with a magnet attached, which picks up the marbles from the bottom of the run. As the mechanism turns, the rhombus shifts and brings the marble-carrying arm to the top of the marble run. There, it’s grabbed by another magnet, which holds the marble for a moment before letting it drop back down through the run.

It’s a simple project that nonetheless would make a brilliant desk toy. It’s also a great way to learn about linkage analysis and designing such systems on your own. If you’re big into marble runs, you might also consider procedurally generating them. Video after the break.

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Cutting Metals With A Diode Laser?

September 21, 2022 by 34 Comments

Hobbyist-grade laser cutters can be a little restrictive as to the types and thicknesses of materials that they can cut. We’re usually talking about CO2 and diode-based machines here, and if you want to cut non-plastic sheets, you’re usually going to be looking towards natural materials such as leather, fabrics, and thin wood.

But what about metals? It’s a common beginner’s question, often asked with a resigned look, that they already know the answer is going to be a hard “no. ” However, YouTuber [Chad] decided to respond to some comments about the possibility of cutting metal sheets using a high-power diode laser, with a simple experiment to actually determine what the limits actually are.

Using an XTool D1 Pro 20W as a testbed, [Chad] tried a variety of materials including mild steel, stainless, aluminium, and brass sheets at a variety of thicknesses. Steel shim sheets in thicknesses from one to eight-thousandths of an inch appeared to be perfectly cuttable, with an appropriate air assist and speed settings, with thicker sheets needing a good few passes. You can definitely see the effect of excess heat in the workpiece, resulting in some discoloration and noticeable warping, but those issues can be mitigated. Copper and aluminium weren’t touched by the beam at all, likely due to the extra reflectivity, but we do have to wonder if appropriate surface treatments could improve matters.

Obviously, we’ve seen that diode lasers can have an impact on metals, simply smearing a little mustard on the workpiece seems to make marking a snap. Whilst we’re on the subject of diode lasers, you can get a lot of mileage from just strapping such a laser module onto a desktop CNC.

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Floppy Disk Sales Are Higher-Density Than You Might Think

September 21, 2022 by 53 Comments

Floppies may be big in Japan, but nostalgic and/or needful Stateside floppy enthusiasts needn’t fret — just use AOL keyword point that browser toward floppydisk.com. There, you can buy new floppies of all sizes, both new and old, recycle your disks, or send them in to get all that precious vintage stuff transferred off of them.

That delightfully Web 1.0 site is owned by Tom Persky, who fancies himself the ‘last man standing in the floppy disk business’. Who are we to argue? By the way, Tom has owned that address since approximately 1990 — evidently that’s when a cyber-squatter offered up the domain for $1,000, and although Tom scoffed at paying so much as $1 for any URL, his wife got the checkbook out, and he has had her to thank for it ever since.

My business, which used to be 90% CD and DVD duplication, is now 90% selling blank floppy disks. It’s shocking to me. — Tom Persky

In the course of writing a book all about yours-truly’s favorite less-than-rigid medium, authors Niek Hilkmann and Thomas Walskaar sat down to talk with Tom about what it’s like to basically sell buggy whips in the age of the electric car.

Tom also owns diskduper.com, which is where he got his start with floppies — by duplicating them. In the 80s and 90s, being in this business was a bit like cranking out legal tender in the basement. As time wore on and more companies stopped selling floppies or simply went under, the focus of Tom’s company shifted away from duplication and toward sales. Whereas the business was once 90% duplication and 10% floppy sales, in 2022, those percentages have flopped places, if you will.

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Mechanical Color Picker Types Hex Codes For You

September 21, 2022 by 18 Comments

Hex codes are a simple, unambiguous way to designate colors in digital media. However, going from a color in your head to a hex code can be difficult for the unpracticed. [Guy Dupont] built a little gadget by the name of the Dial Toner to do it for him (Nitter).

The Dial Toner has two dials for each color channel – Red, Green, and Blue. By turning the dials, one can choose a given color in the 8-bit RGB color space, and that color is then displayed on the device’s included RGB LED. Once selected, the button can be pressed to type the selected color’s hex code into a text box. The Dial Toner runs on a Xiao RP2040 microcontroller board, and is coded in CircuitPython.

[Guy] hopes to sell the Dial Toner on Etsy in future, and is even working on a CMYK version for print addicts. We’ve featured [Guy]’s work here before, too, in the form of his extended-play HitClips cartridges. Video after the break.

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It’s Pi All The Way Down With This Pi-Powered Pi-Picking Robot

September 20, 2022 by 14 Comments

While most of us live in a world where the once ubiquitous Raspberry Pi is now as rare as hens’ teeth, there’s a magical place where they’ve got so many Pis that they needed to build a robotic dispenser to pick Pi orders. And to add insult to injury, they even built this magical machine using a Raspberry Pi. The horror.

This magical place? Australia, of course. There’s no date posted on the Pi Australia article linked above, but it does mention that there’s a Pi 4 Model B running the show, so that makes it at least recent-ish. Stock is stored in an array of tilted bins that a shuttle mechanism accesses via an X-Y gantry. The shuttle docks in front of a bin and uses a stepper-controlled finger to flip a box over the lip holding them in its bin. Once in the shuttle, the order is transported to an array of output bins, where a servo operates a flap to unceremoniously dump the product out for packing and shipping. There’s a video of a full cycle below, but a word of warning — the stepper motors on the X-Y gantry really scream, so you might want to lower the volume.

The article goes into more detail on not only the construction of “Bishop” — named after the heroic synthetic organism from Aliens — but also the challenges faced during construction. It turns out that even when you try to use gravity to simplify a system like this, things can go awry very easily. There’s also a fair bit of detail on the software, which surprisingly centers around LinuxCNC. And there are plans to take this further, with another bot to do the packing, sealing, and labeling of the order. If they need all that automation down there, we guess we found all the missing Pis.

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3D Printed String Vase Shows What’s Possible

September 20, 2022 by 15 Comments

Overhangs are the bane of the melty-plastic 3D printing world. Often, we try to avoid them with creative print alignments, or we compensate with supports. However, [3DPrintBunny] decided to embrace overhangs in the extreme in the design of her creative 3D-printed string vase.

The design is intended to be printed with a larger nozzle, on the order of 0.8 mm or so, at a layer height of 0.6 mm. Under these conditions, the printer nozzle bridges the gap between the vase’s pillars with a single string of molten filament. With the settings just so, the molten filament stays attached during the bridging operation, and creates a fine plastic string between the pillars. Repeat this across the whole design, and you get an attractive string vase.

Amazingly, [3DPrintBunny] didn’t have to do any fancy slicer tricks to achieve this. Stock slicer settings got the job done just fine, and she reports that the model should print on most FDM printers. For her own examples, she printed in a special silver/bronze dual color PLA filament.

It recalls us of efforts to create synthetic hair-like fibers by taking advantage of stringing in 3D printers. Video after the break. Continue reading “3D Printed String Vase Shows What’s Possible” →

Raspberry Pi Grants Remote Access Via PCIe (Sort Of)

September 20, 2022 by 28 Comments

[Jeff] found a Raspberry Pi — well, the compute module version, anyway — in an odd place: on a PCI Express card. Why would you plug a Raspberry Pi into a PC? Well, you aren’t exactly. The card uses the PCI Express connector as a way to mount in the computer and connect to the PC’s ground. The Pi exposes its own network cable and is powered by PoE or a USB C cable. So what does it do? It offers remote keyboard, video, and mouse (KVM) services. The trick is you can then get to the PC remotely even if you need to access, say, the BIOS setup screen or troubleshoot an OS that won’t boot.

This isn’t a new idea. In fact, we’ve seen the underlying Pi-KVM software before, so if you don’t mind figuring out your mounting options for a Raspberry Pi, you probably don’t need this board. Good thing too. Judging by the comments, they are hard to actually buy — perhaps, due to the chip shortage.

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