This Pogo Pin Test Fixture Keep Your SMDs From Taking Flight

December 5, 2023 by Dan Maloney 12 Comments

There’s no denying how useful surface mount technology is, and how enabling the ability to make really small circuits has become. It comes at a price, though; most of us probably know what it’s like for the slightest wrong move to send a part the size of a grain of sand into another dimension.

To help make testing these parts a little easier, [IMSAI Guy] has come up with this clever little SMD test fixture. It’s designed to hook up to another custom board, which in turn connects to a wonderful old Hewlett-Packard 4275A LCR meter. The jig is based on two pogo pins mounted directly across from each other on a scrap of single-clad PCB. The spring-loaded contacts, which short together when not in use, are pulled apart to load an SMD part, like the 1-μH inductors shown in the video below. The pins hold the component firmly and make good electrical contact, allowing hands-free testing without the risk of an errant touch of the test probes sending it flying.

While the test fixture works well for larger SMDs, we could see this being a bit fussy for smaller parts. That would be easy enough to fix with perhaps some 3D-printed arms that retract the pogo pins symmetrically, holding them open until the part is loaded. A centering fixture might help too, as would a clear shield to contain any parts that get the urge to go for a ride. But, for the tactical application [IMSAI Guy] has in mind, this sure seems like enough.

Just getting into surface mount? If so, you might want to check out this handy guide to the often cryptic markings used on SMD parts.

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Mining And Refining: Titanium, Our Youngest Industrial Metal

December 5, 2023 by Dan Maloney 9 Comments

Earlier in this series, we made the case for copper being “the metal that built technology.” Some readers took issue with that statement, noting correctly that meteoric iron and gold were worked long before our ancestors were able to locate and exploit natural copper outcroppings, therefore beating copper to the historical punch. That seems to miss the point, though; figuring out how to fashion gold decorations and iron trinkets doesn’t seem like building the foundations for industry. Learning to make tools from copper, either pure or alloyed with tin to make bronze? Now that’s how you build an industrial base.

So now comes the time for us to make the case for our most recent addition to humanity’s stable of industrial metals: titanium. Despite having been discovered in 1791, titanium remained locked away inside abundantly distributed ores until the 1940s, when the technological demands of a World War coupled with a growing chemical prowess and command of sufficient energy allowed us to finally wrest the “element of the gods” from its minerals. The suddenness of it all is breathtaking, too; in 1945, titanium was still a fantastically expensive laboratory oddity, but just a decade later, we were producing it by the (still very expensive) ton and building an entirely new aerospace industry around the metal.

In this installment of “Mining and Refining,” we’ll take a look at titanium and see why it took us over 11,000 years to figure out how to put it to work for us.

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Cockpit Instrument Respectfully Retasked As A Clock

December 5, 2023 by Dan Maloney 3 Comments

How do you convert an old cockpit instrument into a clock? Easy: just build a circuit that convinces it it’s in the air, and the rest will take care of itself.

Now obviously, little about [porkfreezer]’s conversion of King KI 266 DME into a clock was actually easy; working with avionics rarely is. DME stands for “Distance Measuring Equipment,” an instrument that’s part of the radio navigation suite of many aircraft. DME measures the line-of-sight distance of a plane to a ground station by measuring the time it takes for a signal to return after the plane interrogates it. The plane-mounted equipment includes a UHF transceiver and a display for the cockpit instrument panel, which accepts an analog voltage signal from the transceiver and translates it into a readout on the nice Panaplex digital display.

Rather than gutting the thing and just driving the display directly, [porkfreezer] decided to build a circuit to generate the proper signals for the DME. The board uses a PIC16 and an MCP47C dual 10-bit digital-to-analog converter to generate the voltages needed, while a USB-powered DC-DC converter provides the ±15 volt supply the DME display expects.

Everything lives on a PCB that fits right on the back of the instrument. Sadly, the connector needed to mate up to the one on the instrument was outlandishly expensive — again, avionics — so [porkfreezer] had to solder the board directly to the DME’s pins. Otherwise, this would have been a completely reversible hack.

Still, it’s an interesting reuse of an unusual piece of gear, and one that respects the original design as much as possible. That counts as a win in our book.

Retrotechtacular: The Story Of Turpentine

December 4, 2023 by Dan Maloney 33 Comments

If someone in 2023 has ever had much call to use turpentine, chances are good it was something to do with paint or other wood finishes, like varnish. Natural turpentine is the traditional solvent of choice for oil paints, which have decreased in popularity with the rise of easy-to-clean polymer-based paints and coating. Oh sure, there are still those who prefer oil paint, especially for trim work — it lays up so nice — but by and large, turpentine seems like a relic from days gone by, like goose grease and castor oil.

It wasn’t always so, though. Turpentine used to be a very big deal indeed, as shown by this circa 1940 documentary on the turpentine harvesting and processing industry. Even then it was only a shadow of its former glory, when it was a vital part of a globe-spanning naval empire and a material of the utmost strategic importance. “Suwanee Pine” shows the methods used in the southern United States, where fast-growing pines offer up a resinous organic gloop in response to wounds in their bark. The process shown looks a lot like the harvesting process for natural latex, with slanting gashes or “catfaces” carved into the trunks of young trees, forming channels to guide the exudate down into a clay collecting cup.

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The Hoarder’s Dilemma Hack Chat

December 4, 2023 by Dan Maloney 31 Comments

Join us on Wednesday, December 6 at noon Pacific for the The Hoarder’s Dilemma Hack Chat with Gabe Emerson!

There’s a lot to be said for the power of a well-stocked junk bin. It’s almost a magical thing, being able to dive into a random box and retrieve just the right part to perform a needful repair or to complete a project without the need to hit the web or hop in the car for a trip to the hardware store. For those who pride themselves on their resourcefulness, it can be a heady experience indeed.

But as with everything, such feats of fix-it come at a price. That little squirt of dopamine that comes from having just the right thing can make your monkey brain fixate on a simple equation: “More stuff is better stuff.” The higher and deeper your stash, the better your chances of having what you need, assuming you can find it, of course. This way lies madness, and perhaps an appearance on a reality TV show.

Is there a better way? It’s hard to say, but we figured it would be a good idea to loop in someone with a lot of experience collecting junk that somehow finds its way into some pretty cool projects. Gabe Emerson runs the popular and aptly named “saveitforparts” channel over on YouTube, and fancies himself an accomplished hoarder. We’d have to agree, given his recent 1,000-mile drive to pick up a used geodesic dome, or his ever-increasing collection of RV satellite dishes, which he somehow puts to good use. His junk collection is pretty epic; he even has a whole piece of property devoted to the larger pieces of his collection, like an entire monorail train. He seems uniquely qualified to discuss the “Hoarder’s Dilemma” and the painful process of deciding what stays and what goes.

Our Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, December 6 at 12:00 PM Pacific time. If time zones have you tied up, we have a handy time zone converter.

This Laser-Cut One-Piece Wedge Tenon Locks Wood Joints Tight

December 4, 2023 by Dan Maloney 24 Comments

Woodworkers have always been very clever about making strong and attractive joints — think of the strength of a mortise and tenon, or the artistry of a well-made dovetail. These joints have been around for ages and can be executed with nothing more than chisels and a hand saw, plus a lot of practice, of course. But new tools bring new challenges and new opportunities in joinery, like this interesting “hammer joint” that can be made with a laser cutter.

This interesting joint comes to us from [Jiskar Schmitz], who designed it for quick, solid, joints without the need for glue or fasteners. It’s a variation on a wedged mortise and tenon joint, which strengthens the standard version of the joint by using a wedge to expand the tenon outward to make firm contact with the walls of the tenon.

The hammer joint takes advantage of the thin kerf of a laser cutter and its ability to make blind cuts to produce a tenon with a built-in wedge. The wedge is attached to a slot in the tenon by a couple of thin connectors and stands proud of the top of the tenon. The tenon is inserted into a through-hole mortise, and a firm hammer blow on the wedge breaks it free and drives it into the slot. This expands the tenon and locks it tightly into the mortise, creating a fairly bulletproof joint. The video below tells the tale.

While the hammer joint seems mainly aimed at birch plywood, [Jiskar] mentions testing it in other materials, such as bamboo, MDF, and even acrylic, although wood seems to be the best application. [Jiskar] also mentions a potential improvement: the addition of a ratchet and pawl shape between the wedge and the slot in the tenon, which might serve to lock the wedge down and prevent it from backing out.

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Hackaday Links: December 3, 2023

December 3, 2023 by Dan Maloney 28 Comments

Sure, it does less than originally promised, but hey — at least it’s more expensive. That about sums up Tesla fans’ feelings after the long-awaited Cybertruck reveal at the Texas Gigafactory on Thursday, where Elon Musk himself handed over the keys — or their Cyber equivalent — to a few new owners. These are expensive machines — $61,000 for the two-motor model, and just shy of $100,000 for the three-motor all-wheel-drive model with all the bells and whistles. That’s considerably more than they were expected to cost back in 2019, a fact which may be at least partially behind the drop in Tesla shares after the launch.

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