3D Printed Pen Plotter Is As Big As You Need It To Be

There’s nothing quite like building something to your own personal specifications. It’s why desktop 3D printers are such a powerful tool, and why this scalable plotter from the [Lost Projects Office] is so appealing. You just print out the end pieces and then pair it with rods of your desired length. If you’ve got some unusually large computer-controlled scribbling in mind, this is the project for you.

The design, which the team calls the Deep Ink Diver (d.i.d) is inspired by another plotter that [JuanGg] created. While the fundamentals are the same, d.i.d admittedly looks quite a bit more polished. In fact, if your 3D printed parts look good enough, this could probably pass for a commercial product.

For the electronics, the plotter uses an Arduino Uno and a matching CNC Shield. Two NEMA 17 stepper motors are used for motion: one to spin the rod that advances the paper, and the other connected to a standard GT2 belt and pulley to move the pen back and forth.

We particularly like the way [Lost Projects Office] handled lifting the pen off the paper. In the original design a solenoid was used, which took a bit of extra circuitry to drive from the CNC Shield. But for the d.i.d, a standard SG90 servo is used to lift up the arm that the pen is attached to. A small piece of elastic puts tension on the assembly so it will drop back down when the servo releases.

If this plotter isn’t quite what you’re after, don’t worry. There’s more where that came from. We’ve seen a number of very interesting 3D printed plotters that are just begging for a spot in your OctoPrint queue.

Glia Is Making Open Medical Devices, And You Can Help

The Glia project aims to create a suite of free and open-source medical equipment that can be assembled cheaply and easily when and where it’s needed. Even essential tools like stethoscopes and tourniquets can be difficult to acquire in certain parts of the world, especially during times of war or civil unrest. But armed with a 3D printer and the team’s open-source designs, an ad-hoc factory can start producing these lifesaving tools anywhere on the planet.

Glia member [Tarek Loubani] has recently written a blog post discussing the team’s latest release: an otoscope that can be built for as little as $5. Even if you don’t recognize the name, you’ve almost certainly seen one of them in use. The otoscope is used to look inside the ear and can be invaluable in diagnosing illnesses, especially in children. Unfortunately, while this iconic piece of equipment is quite simple on a technical level, professional-quality versions can cost hundreds of dollars.

Now to be fair, you’ll need quite a bit more than just the 3D printed parts to assemble the device. The final product requires some electrical components such as a battery holder, rocker switch, and LED. It also requires a custom lens, though the Glia team has thought ahead here and provided the files for printable jigs that will allow you to cut a larger lens down to the size required by their otoscope. In a situation where you might have to improvise with what you have, that’s a very clever design element.

So far the team is very happy with how the otoscope performs, but they’ve run into a bit of a logistical snag. It turns out that early work on the project was done in the web-based TinkerCAD, which isn’t quite in line with the team’s goals of keeping everything free and open. They’d like some assistance in recreating the STLs in FreeCAD or OpenSCAD so they’re easier to modify down the road. So if you’re a FOSS CAD master and want to earn some positive karma, head over to the GitHub page for the project and put those skills to use.

We’ve previously covered Glia’s work with 3D printed tourniquets to treat gunshot wounds, a project that led to [Tarek] himself being shot by a sniper while attempting to field test the design in Gaza. If that’s not commitment to the principles of open-source hardware, we don’t know what is.

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Old Chainsaw Repurposed For Kitchen Use

There are many ways to keep critical appliances running during a power outage. Maybe a UPS for a computer, a set of solar panels to charge your phone, or even a generator to keep your refrigerator or air conditioning working. This modification to a standard blender will also let you ride through a power outage while still being able to make delicious beverages. It runs on gasoline.

The build uses an old chainsaw to power the blades of the blender. [Bob] was able to design and build an entirely new drivetrain to get this device to work, starting by removing the chainsaw chain and bar and attaching a sprocket to the main shaft of the motor. A chain connects it to a custom-made bracket holding part of an angle grinder, which supports the blender jar. Add in a chain guard for safety and you’ll have a blender with slightly more power than the average kitchen appliance.

The video of the build is worth watching, even if your boring, electric-powered blender suits your needs already. The shop that [Bob] works in has about every tool we could dream of, including welders, 3D printers, band saws, and even a CNC plasma cutter. It reminds us of [This Old Tony]’s shop.

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A Custom Milled Jig For Smart Bulb Programming

Who would have thought that some day we’d need programming jigs for our light bulbs? But progress marches on, and as there’s currently a number of affordable Internet-controlled bulbs powered by the ESP8266 on the market, we’re at the point where a tool to help update the firmware on the light over your kitchen sink might be something nice to have. Which is why [cperiod] created this programming jig for AiLight smart bulbs.

Flashing the AiLight bulbs is easy enough, there’s a series of test points right on the face of the PCB that you can hook up to. But if you’re updating more than one of them, you don’t want to have to solder your programmer up to each bulb individually. That’s where the jig comes in. [cperiod] says there are already some 3D printed designs out there, but they proved to be a bit finicky.

The design that [cperiod] came up with and eventually milled out on a 1610 CNC router is quite simple. It’s effectively just a holder to keep the five pogo pins where they need to be, and a jumper that lets you toggle the chip’s programming mode (useful for debugging).

The neat trick here are the “alignment pins”, which are actually two pieces of 14 gauge copper wire that have had their ends rounded off. It turns out these will slip perfectly into holes on the AliLight PCB, ensuring that the pogo pins end up on target. It works well enough that you can hold the bulb and jig in one hand while programming, it just needs a little downwards pressure to make good contact.

We’ve previously seen how easily you can replace the firmware on some of these ESP8266 bulbs. While there’s certainly a downside to these bulbs being so simple to modify, it’s hard to deny their hackability makes them very appealing for anyone looking to roll their own network-controlled lighting system.

Fail Of The Week: Supercapacitor Spot Welder

[Julian] needed to weld a bit of nickel to some steel and decided to use a spot welding technique. Of course he didn’t have a spot welder sitting around. Since these are fairly simple machines so [Julian] set out to build a spot welder using a charged supercapacitor. The fundamentals all seem to be there — the supercap is a 100 Farad unit and with a charge of 2.6V, that works out to over 300 joules — yet it simply doesn’t work.

The problem is in how the discharge energy is being directed. Just using the capacitor would cause the charge to flow out as a spark when you got near the point to discharge. To combat this, [Julian] put a microswitch between the capacitor and the copper point he expected to use as the welding tip. The microswitch, of course, is probably not the best for carrying a large surge of current, so we suspect that may be part of why he didn’t get great results.

The other thing we noticed is that he used a single point and used the workpiece as a ground return. Most spot welders use two points near each other or on each side of the workpiece. The current from the capacitor is probably just absorbed by the relatively large piece of metal.

The second video below from [American Tech] shows a 500F capacitor doing spot welding with little more than two wires and it seems to work. Hackaday’s own [Sean Boyce] even made one out of some whopping 3000F caps. It did work, although he’s been pursuing improvements.

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DIY PC Test Bench Puts Hardware Troubleshooting Out In The Open

If you’ve built a few PCs, you know how frustrating troubleshooting can be. Finding a faulty component inside the cramped confines of a case can be painful — whether its literal when sharp edges draw blood, or just figurative when you have to open that cramped case multiple times to make adjustments.

[Colonel Camp] decided to make life a bit easier by building this PC test bench which makes component troubleshooting much easier and can be built with old parts you probably have lying around. [Camp] was inspired by an old Linus PC Tech Tips video on the same topic. The key to the build is an old PC case. These cases are often riveted together, s a drill makes quick work of disassembling the chassis to easily get to all of the components. The motherboard pan and rear panel/card cage become the top shelf of the test bench, while the outer shell of the case becomes the base and a storage area. Two pieces of lumber support the upper shelf. The build was primed and painted with several coats of grey.

[Camp] built up his testbench with a modest motherboard, cooler and a 970 video card. He loaded up Manjaro Linux to verify everything worked. The basic hardware has already been replaced with a new system including a ridiculously huge cooler. But that’s all in a day’s work for a test bench PC.

We’ve seen some wild workbenches over the years, and this one fits right in for all your PC projects. Check out the video after the break!

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Control The Suck With This Manual Vacuum Pick-And-Place Tool

The tapes that surface-mount devices come in may be optimized for automated pick and place, but woe betide those who try to dig components out manually. No matter what size package, the well on the tape seems to be just a wee bit too small to allow tweezers to grip it, so you end up picking the thing up edgewise or worse, pinching too tight and launching the tiny thing into The Void. We hope you ordered extra.

Such circumstances are why vacuum handlers were invented, but useful as they are for picking and placing SMDs, they aren’t perfect. [Steve Gardener]’s sub-optimal experience with such tools led him to build this custom vacuum pick-and-place tool. It’s based on an off-the-shelf Weller unit, of which only the handpiece remains. A bigger, more powerful vacuum pump is joined in a custom enclosure by a PCB with a PIC18F13K22 microcontroller, a power supply, a solenoid to control the vacuum, and a relay to switch the pump. A footswitch starts the pump and closes the vacuum vent; letting off the pedal opens the vent to drop the part, while the pump keeps running for a variable time. This lets him rapidly work through a series of parts without having to build vacuum back up between picks. The video below shows the build and the tool in action.

We love the idea of this tool, and the polished look is pretty slick too. If manual pick-and-place isn’t for you, though, maybe converting a 3D-printer into an automated PnP is something to check out.

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