A French Press You Can Take Out Camping

February 10, 2020 by Lewin Day 41 Comments

There’s many a hacker that considers coffee a necessary fuel, without which, little work can be achieved. This applies whether in the office or traipsing around in the great outdoors. For the latter situation, [Poehls05] developed a robust French press that’s well suited to field use.

Typically, a French press consists of a plunger assembly which moves within a glass vessel. This is fragile and unwieldy for throwing in a backpack. Instead, in this design, the plunger assembly is harvested from an existing press and repurposed to fit within a sturdy Nalgene water bottle, designed specifically for overlanding.

The modifications involve cutting the existing press plate into three slices, and reassembling with hinges so it may fold. The plunger rod is then modified to make it possible to tilt the press plate relative to the rod. These modifications allow the plunger to be slid into the narrower neck of the Nalgene water bottle, and also enable the plunger rod to work with the original screw-down lid. In this configuration, the bottle is no longer water tight, but can be converted to normal use by swapping a regular lid back on top.

With the changes in place, the plastic bottle can easily be used in the same manner as a regular French press. Simply fill with hot water, allow the grounds to steep, and then press and pour. It’s a great way to make high-quality coffee in the wilderness, and one that may prove popular with hackers who don’t wish to give up the finer things when out and about. We’ve also featured tricks to make the most of hotel coffee, too.

Bringing A Swap Meet 3D Printer Back From The Dead

February 10, 2020 by Tom Nardi 9 Comments

At a recent swap meet, [digitalrice] found what appeared to be a like-new QIDI X-Plus 3D printer. It wasn’t clear what was wrong with it, but considering it retails for $900 USD, he figured the asking price of $150 was worth the gamble. As you might expect, the printer ended up being broken. But armed with experience and a supply of spare parts, he was able to get this orphaned machine back up and running.

The first and most obvious problem was that the printer’s Z axis didn’t work properly. When the printer tried to home the axis, one of the motors made a terrible noise and the coupler appeared to be spinning backwards. From his experience with other printers, [digitalrice] knew that the coupler can slip on the shaft, but that didn’t appear to be the case here. Removing the stepper motor and testing it in isolation from the rest of the machine, he was able to determine it needed replacing.

Unfortunately, the spare steppers he had weren’t actually the right size. Rather than waiting around for the proper one to come in the mail, he took an angle grinder to the stepper’s shaft and cut off the 5 mm needed to make it fit, followed by a few passes with a file to smooth out any burrs. We’re not sure we’d recommend this method of adjustment under normal circumstances, but we can’t argue with the results.

The replaced Z motor got the printer moving, but [digitalrice] wasn’t out of the woods yet. At this point, he noticed that the hotend was hopelessly clogged. Again relying on his previous experience, he was able to disassemble the extruder assembly and free the blob of misshapen PLA, leading to test prints which looked very good.

But success was short lived. After swapping to a different filament, he found it had clogged again. While clearing this second jam, he realized that the printer’s hotend seemed to have a design flaw. The PTFE tube, which is used to guide the filament down into the hotend, didn’t extend far enough out. Right where the tube ended, the filament was getting soft and jamming up the works. With a spare piece of PTFE tube and some manual reshaping, he was able to fashion a new lining which would prevent the filament from softening in this key area; resulting in a more reliable hotend than the printer had originally.

It’s great to see this printer repaired to working condition, especially since it looks like [digitalrice] was able to fix a core design flaw. But a broken 3D printer can also serve as the base for a number of other interesting projects, should you find yourself in a similar situation. For example, replacing the extruder assembly with a digital microscope can yield some very impressive results.

Simple 3D Printed Robotic Arm Uses Compliant Mechanism

February 9, 2020 by Danie Conradie 5 Comments

Learning through play is effective for humans of all ages, and since 2016 [slantconcepts] has been designing STEM kits that help teach kids to build their future overlords. They are launching version 3 of their LittleArm robotic arm, and the progression from version 1 is an interesting study in simplification and parts count reduction without sacrificing functionality.

In all of the LittleArm versions the main mechanical components are 3D printed, and driven by 3 servos for motion plus one additional servo to run the gripper. These kits are specifically intended to be built and disassembled repeatedly, and classrooms are a great place for small screws to easily disappear, so reducing the number of screws was a big goal for v3. The gripper/forearm shows the most dramatic improvement from the previous versions, being simplified from 8 separate components to a single 3D printed part by using a compliant mechanism — that squiggly pattern that allows the gripper to flex into place. The gripper tips also feature a simple “cutout” that allow it more easily grasp horizontal objects.

An Arduino Nano based expansion board is used to control the arm, with a HC-06 Bluetooth module to allow it to be controlled via a smart phone app. Various sensors can also be added to expand the kit’s capabilities. Unfortunately the mechanical design is not open source, but it can still be a source of inspiration for your own design projects.

Hopefully this kit will inspire some future hackers to build a more advanced 3D printed version, or even a giant hydraulic powered arm.

C#, The Language For All Platforms – Now Including Windows 3.11 And DOS

February 9, 2020 by Jenny List 34 Comments

The Microsoft .NET framework has been with us in one form or another since the millennium, and though it has remained largely the preserve of the Microsoft universe, it has found its way since then through a variety of implementations to other platforms including MacOS and GNU/Linux. In Microsoft terms though its history goes back only as far as Windows 98, earlier MS operating systems remain off-limits.

Just a glimmer of .NET in DOS and Windows 3.11 comes courtesy of [Michal Strehovský], who has successfully compiled .net C# code for both Windows 3.11 and DOS. An in-depth explanation comes courtesy of [Scott Hanselman], and it involves some tricks spanning the decades since the early 1990s. The .NET Core compiler’s object files can be fed into the linker that shipped with an ancient version of Microsoft’s C++ compiler, which when used with Microsoft’s Win32s compatibility layer that brought some of Windos NT’s APIs to the 16-bit OS, allows C# from 2020 to run as though it were 1992 again. Meanwhile the DOS version uses .NET Core’s ability to produce self-contained executables along with some very significant tricks to pare down the size of the finished program from many megabytes to an eventual DOS-suitable 27k. Remember the apocryphal Bill Gates quote, that “640k should be enough for anyone“, that refers to the maximum memory available to DOS without extra memory-extending tricks.

Neither piece of software is especially useful, and we can’t see a rush of C# coders to these new platforms. But we applaud him for his ingenuity, and getting old hardware to do new tricks is right up our alley. It’s certainly dredged up a few memories from back in the day for us. Meanwhile we’ve featured .NET in a few projects over the years, most recently on an FPGA.

Hackaday Links: February 9, 2020

February 9, 2020 by Dan Maloney 21 Comments

In case you thought that we learned everything we need to know to land on the Moon fifty years ago, think again. NASA still has a lot of questions, and has scheduled the first of many commercial missions designed to fill in the blanks. As part of the Artemis program, which aims to land the first women and the next men on the Moon by 2024, NASA’s Commercial Lunar Payload Service (CLPS) will send 16 science payloads to the Moon via two separate commercial flights. The two companies, Astrobotics and Intuitive Machines, will send landers to the Moon in 2021 using a ULA Vulcan Centaur and a SpaceX Falcon 9, respectively. Fourteen companies were selected for CLPS, and with much to learn (or relearn) about landing and working on the Moon, watch for many more flights in the years to come. We’re all for the commercialization of space, but we have to admit that things were easier to keep track of when space exploration was a little more monolithic.

It looks like millions of BlackBerry phone users will have to find something else to do with their thumbs now that TCL is getting out of the BlackBerry business. The Chinese company announced this week that they would no longer have the rights to manufacture BlackBerry-branded phones like the Key2 as of August 31, 2020. Crackberry addicts were understandably upset, but all may not be lost for those who can’t stand the virtual keyboards on most other smartphones, as there’s still a chance another manufacturer will step in to fill the void.

Hypothetical situation: You’re in need of a car, so you go to a used car dealer. You see a nice car, take it for a test drive, and decide to buy it. Money is exchanged, paperwork done, and the salesman hands you the keys. You go out to the lot to drive your new ride home only to find out that the mechanic has removed the tires. When you ask what the deal is, the salesman says, “Sorry, you didn’t buy a license for the tires.” Hypothetical perhaps, but not far off from what happened to one Tesla Model S buyer when an over-the-air update disabled the Enhanced Autopilot and Full Self-Driving features he paid for. Tesla didn’t see it that way, though, claiming that he’d need to pony up to use the new features, which originally sold for $8,000. It raises interesting questions about how the secondary automotive market will respond to the increasingly complicated relationship between hardware and software, and what you’re actually paying for when you buy a car.

Back in the early days of Bitcoin, skeptics used to dismiss the cryptocurrency by saying, “When you can pay your taxes with it, then it’s real money.” Well, that day is apparently here for the municipality of Zermatt in Switzerland, where it was announced that Bitcoin will be accepted as payment for local taxes and other official fees. The Zermatt city hall has installed a Bitcoin point-of-sale terminal, or payments can be made directly from a Bitcoin wallet after filling out the proper paperwork. Bitcoin as legal tender for public debts is not exactly new; Ohio was doing it back as far as 2018. But we find the economic implications of this interesting — as our resident econometrician [Elliot Williams] pointed out, paying taxes in anything but the national currency was considered preposterous not that long ago.

Why Settle For The Standard Catan Board?

February 9, 2020 by Kristina Panos 3 Comments

Let’s face it, game night can get downright rowdy. Whether your game nights involve wine and cats, beer and dogs, or vodka and bear cubs, things happen. Maybe the robber gets batted irretrievably far under the couch, or someone gesticulates wildly and spills wine all over your sheep. [EEEEEEEEEDEN]’s gatherings were getting way out of hand, and it was time to design a custom Catan board.

But she didn’t stop with the board tiles — this is Catan redesigned from the ground up, including the pieces, the resource cards, and a custom storage box. [EEEEEEEEEDEN] even planned for player expansion by designing a leaf to drop in the middle. There are a few hundred magnets built into the frame, so there shouldn’t be any more lost pieces. And as far as liquor-proofing all the cardboard goes, [EEEEEEEEEDEN] designed new board tiles and cards, laser cut them from acrylic, and painstakingly painted them all with Plasti-Dip spray.

We think it’s gorgeous, but understand that maybe this minimalist style isn’t for everyone. If you want to go custom, it’s hard to argue against the beauty of 3D Catan.

Thanks to [Johannes] for the tip! via /r/DIY

Sort The Rainbow With An Algorithm Machine

February 9, 2020 by Kristina Panos 12 Comments

When you’re trying to learn how an algorithm works, it’s not always easy to visualize what’s going on. Well, except for maybe binary sort, thanks to the phone book. Professor [thatguyer] is a computer science teacher who wanted a way to help his students visualize the process of algorithms and at the same time, get a grasp on their resource cost.

The Algorithm Machine can demonstrate 8 different search and sort algorithms using two 100-count strips of RGB LEDs — one to represent an array of integers, and one to create indicators pointing to the integers under scrutiny.

This functional beauty is totally interactive, too. Once the user chooses the values and the algorithm and starts the process, they can speed it up or slow it down with the rotary encoder, or pause to discuss and start again with that slick triangular play button. We particularly like the control button wiring harness [thatguyer] created to keep everything neat and hot-swappable.

This iteration uses 3D printed face plates to give the LEDs shape, but in an early version, [thatguyer] cut and sanded a ton of circles out of brass tubing, and folded as many triangles cut from disposable baking pans. The world could use more teachers as committed as [thatguyer]. This really seems like a handy teaching aid for these concepts, and we wish we’d had one in class to play around with. Here’s your algorithm for watching the demo: click break, press play, enjoy.

If you’re still confused, there are other ways to understand algorithms through visualization. Failing all that, just watch these Hungarian folk dancers work out various algo-rhythms.

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