3D Printed Splint Goes Toe To Toe With Medical Grade Equipment

July 6, 2022 by 11 Comments

When you think of medical devices, the idea of high end, well, pretty much everything, comes to mind. This is definitely the case when it comes to prosthetics, or in this similar case, custom fit splints. A hacker by the name of [sammyizimmy] wasn’t put off by the complexity of a custom splint for his fractured big toe, and a great hack made it all possible.

InVesalius reconstructs the CT Scan imagery

The story starts with a fractured toe, and an open source project called InVesalius. Instead of doing an X-Ray on his toe, [sammyizimmy]’s doctor decided to do a Computed Tomography scan (aka CT Scan) to get a look at the damage. For being as ubiquitous as they are, it’s easy to forget that a CT scan is an extremely detailed look at both internal and external parts.

The hack really began when [sammyizimmy] asked his radiologist for a copy of the CT Scan. This is something most radiologists will provide upon request, although many people don’t know you can even ask. [sammyizimmy] took his CT scan and opened it up in InVesalius, and then reconstructed the skin layer only, and then… head over to the “3d printed Toe Splint” page at Hackaday.io for the rest!

If medical hacks are are your kind of medicine, you might appreciate this HDD-Turned-Centrifuge too!

3D Print Your Own Multi-Color Filament

July 6, 2022 by 11 Comments

Interested in experimenting with your own multi-color filament? [Turbo_SunShine] says to just print your own, and experiment away! Now, if you’re thinking that 3D printing some filament sounds inefficient at best (and a gimmick at worst) you’re not alone. But there’s at least one use case that it makes sense for, and maybe others as well.

Printing with bi-color filament results in an object whose color depends on viewing angle, and part geometry.

There is such a thing as bi-color filament (like MatterHackers Quantum PLA) which can be thought of as filament that is split down the center into two different colors. Printing with such filament can result in some trippy visuals, like objects whose color depends in part on the angle from which they are viewed. Of course, for best results it makes sense to purchase a factory-made spool, but for light experimenting, it’s entirely possible to 3D print your own bi-color filament. Back when [Turbo_SunShine] first shared his results, this kind of stuff wasn’t available off the shelf like it is today, but the technique can still make sense in cases where buying a whole spool isn’t called for.

Here is how it works: the 3D model for filament is a spiral that is the right diameter for filament, printed as a solid object. The cross-section of this printed “filament” is a hexagon rather than a circle, which helps get consistent results. To make bi-color filament, one simply prints the first half of the object in one color, then performs a color change, and finishes the print with a second color. End result? A short coil of printed “filament”, in two colors, that is similar enough to the normal thing to be fed right back into the printer that created it. This gallery of photos from [_Icarus] showcases the kind of results that are possible.

What do you think? Is 3D printing filament mainly an exercise in inefficiency, or is it a clever leveraging of a printer’s capabilities? You be the judge, but it’s pretty clear that some interesting results can be had from the process. Take a few minutes to check out the video (embedded below) for some additional background.

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Scratch-Built Electric Buggy Tears Up The Dunes

July 5, 2022 by 14 Comments

It’s a fair bet to say that the future of personal transportation will probably be electric. In support of that, every major car manufacturer either has an electric drivetrain option available now, or they’re working furiously on developing one. And while it’s good that your suburban grocery grabber will someday be powered by the sun, what about the pressing need for EVs that are just plain fun to drive?

To fill the fun gap, at least for now, [James Biggar] built what you can’t buy: an all-electric dune buggy. And lest you think this was a kit build, be assured that the summary video below shows this little sand rail was 100% scratch-built. The chassis is fabricated from bent tubing, and welded up using a clever plywood template to get the angles just right. The buggy has four-wheel independent suspension and a wide, aggressive stance to handle rough terrain. The body panels are sheet aluminum bent on a custom-built brake, which was also used to form the Plexiglas windshield with a little help from a heat gun.

While the bodywork makes the buggy pretty sick looking, the drivetrain is just as impressive. [James] used an ME1616, a liquid-cooled 55-kW beast. A chain drive couples the motor to a differential from a Honda CR-V which has a limited-slip modification installed. The batteries are impressive, too — 32 custom-made lithium-iron-phosphate batteries made from 32650 cells in vacuum-formed ABS plastic shells that nest together compactly. It all adds up to a lot of fun in the dirt; skip to 23:37 in the video to see what this thing can do.

Honestly, the level of craftsmanship here is top-notch, and is all the more impressive in that it’s not fancy — just good, solid methods and lots of hard work. We’d love to have the time and resources to put into something like this — although a drop-in crate motor EV might be a satisfying build too.

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Classic Amp Revived With A Pi

July 5, 2022 by 4 Comments

Guitar amplifiers have a hard life, and as anyone who’s run a venue can tell you, they often have significant electrical issues after a life on the road. [Dsagman] had a Vox amplifier with fried internals, and rather than repair the original he rebuilt it with a Raspberry Pi inside to provide a fully-loaded array of effects.

Though the subject is the Vox, it’s best to see this as more a tale of how to create a guitar effect array in a Pi than specifically put it in an amplifier. The Pi has an audio board and an MCP3008 ADC added to it, and using those two it takes its inputs from a series of potentiometers and process the audio passing through the audio board. In addition there are a series of LED indicators and an LED bar graph to keep the user in touch with what’s going on.

The whole lot is nicely integrated in the VOX case with all the potentiometers on an aluminium panel. He discusses amplifier choice, but as you might expect the final choice is a Class D module. All in all an amp many readers would probably go for.

As long-time readers will remember, guitar effects have made quite a few appearances around here. Continue reading “Classic Amp Revived With A Pi” →

A clock with a VFD display in an orange TV-like case

Never Miss An Email With This 1970s Style Desktop Notifier

July 5, 2022 by 12 Comments

If you like the 1970s aesthetic but think bell-bottoms, big hair and psychedelic wallpaper are a bit too much in this day and age, you might want to have a look at [Pierre Muth]’s latest build, The Absurd Notifier. It’s a useful desk accessory that adds just a little bit of ’70s flair to your office: housed inside what looks like an orange TV standing on shiny metal feet is a little gadget that can tell you if you’ve got important email messages waiting or an appointment coming up.

[Pierre] built the system around a Garmin Vivosmart 3 smartwatch that he bought very cheaply because it had a broken display. The display’s pinout and protocol were of course undocumented, so [Pierre] hooked up his logic analyzer to try and figure out how it worked. It turned out to be a simple SPI setup, and with a bit of trial and error he was able to extract the images that the watch was sending out.

To replace the broken screen, [Pierre] turned to some 128×64 pixel VFD displays that he had left over from an earlier project. Their resolution was exactly the same as the Garmin’s original OLED display, but their interface wasn’t: the VFDs expected 115k2 serial data. Programming a PIC microcontroller with an SPI port on one side and a UART port on the other made for a simple bridge between the two.

[Pierre] then designed and 3D printed a case reminiscent of a 1970s TV, with matching bright orange color. The end result is a funky little retro clock that shows notifications on a vintage green display. If you like desktop notifiers, we seen several neat ones alerting their owners about things ranging from new YouTube subscribers to the ISS passing by.

Continue reading “Never Miss An Email With This 1970s Style Desktop Notifier” →

New Gear Saves Old Printer

July 5, 2022 by 18 Comments

As the digital photographic revolution took off, and everyone bought a shiny new film-less camera, there was a brief fad for photo printers. The idea was you’d have the same prints you’d always had from film, but the media for these printers would invariably cost a fortune so consumers moved on pretty quickly.

Now the pop up in second-hand stores and the like, which is how [Amen] acquired a Canon Selphy 740. It didn’t work, and on investigation it was found that a particularly tiny plastic gear had failed. Most people would have tossed the printer in the trash, but they instead opted to CNC-machine a new gear. It’s not everyday you tackle a job this small, so it makes for an interesting tale.

While the first instinct might be to reach reach for a CAD package, [Amen] instead wrote a script to create the raw GCode. The machining is done with a 0.2 mm bit ground to the desired profile. The result: a gear that gets the printer working again. It’s a dye-sublimation printer that leaves a negative image in the cartridge, allowing negative prints to be made with a bit of cartridge rewinding. And for those who might have ended up with a Selphy of their own, there’s a further post about using cheaper aftermarket cartridges.

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The Warm Glow Of A Luminous Clock

July 5, 2022 by 8 Comments

It seems there will never be an end to the number of ways to show the time. The latest is the LumiClock from [UK4dshouse], and it uses the seldom-seen approach of a sheet of luminous paper excited by a strip of UV LEDs that pass over it guided by a lead screw.

At its heart is a micro:bit, which generates the time in dot-matrix digital form as the LEDs are moved across the sheet. It in turn has a real-time-clock module to keep it on time, and it drives a little DC motor via a robotics driver board. The appearance of the whole devices is similar to an X-Y plotter without the Y axis, as a 3D-printed carrier is moved by the lead screw and slides along a pair of stainless steel tubes. The result is an unusual and eye-catching timepiece, whose retro dot-matrix numerals fade away and are refreshed with the new time.

We’ve had a bit of a play ourselves with UV luminous materials, and we can confirm they make an interesting alternative to some other display ideas in dimmer environments. This isn’t the first such clock we’ve shown you.