A closeup of the faulty section of the dial - you can spot the plastic rivets that broke off

The Tale Of Two Broken Flukes

March 1, 2023 by Arya Voronova 11 Comments

Some repairs happen as if by pure luck, and [Sebastian] shows us one such repair on Hackaday.io. He found two Fluke 175 meters being sold on eBay, with one having a mere beeper issue, and another having a “strange error”. Now, theoretically, swapping beepers around would give you one working meter and a kit of spare parts – but this is Fluke we’re talking about, and [Sebastian] wasn’t satisfied leaving it there.

First, he deduced that the beeper issue could be fixed by repositioning the piezo disk – and indeed, that brought the meter number one to working order. This left the mysterious error – the meter would only power up in certain rotations of the dial, and would misbehave, at that. Disassembly cleared things up – the dial mechanics failed, in that a half of the metal contacts came detached after all the plastic rivets holding the metal piece in place mysteriously vanished. The mechanics were indeed a bit intricate, and our hacker hoped to buy a replacement, but seeing the replacement switch prices in three-digit range, out came the epoxy tube.

An epoxy fix left overnight netted him two perfectly working Fluke meters, and while we don’t know what the listing price was for these, such a story might make you feel like taking your chances with a broken Fluke, too. The tale does end with a word of caution from [Sebastian], though – apparently, cleaning the meters took longer than the repairs themselves. Nevertheless, this kind of repair is a hobbyist’s dream – sometimes, you have to design a whole new case for your meter if as much as a wire breaks, or painstakingly replace a COB with a TQFP chip.

Utility Mat Turns Waste Epoxy Into Useful Tools

February 9, 2023 by Lewin Day 46 Comments

Epoxy is a great and useful material typically prepared by mixing two components together. But often we find ourselves mixing too much epoxy for the job at hand, and we end up with some waste left behind. [Keith Decent’s] utility mat aims to make good use of what is otherwise waste material.

The concept is simple yet ingenious. It’s a flexible mat that serves as a mold for all kinds of simple little plastic workshop tools. The idea is that when you have some epoxy left over from pouring a finish on a table or laying up some composites, you can then pour the excess into various sections of the utility mat. The epoxy can then be left to harden, producing all manner of useful little tools.

It may seem silly, but it could save your workshop plenty of nickels and dimes. Why keep buying box after box of stir sticks when you can simply make a few with zero effort from the epoxy left from your last job? The utility mat also makes other useful nicknacks like glue spreaders, scrapers, wedges, and painter’s pyramids.

We’ve seen other great recycling hacks over the years too. Video after the break.

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Domesticating Plasma With A Gorgeous Live Edge Table

January 19, 2023 by Tom Nardi 16 Comments

If you’ve been reading Hackaday for any length of time, you’ll know we don’t often cover woodworking projects here. It’s not because we aren’t impressed with the skill and effort that folks put into them, and truth be told, we occasionally we even feel a pang of envy when looking at the final result. It’s just that, you know…they’re made of wood.

But when [Jay Bowles] of Plasma Channel sent in this live edge wooden table that features not only a pair of custom-made neon tubes but the burned out transistors and ICs from his previous high-voltage exploits — we knew this wasn’t exactly your grandpa’s idea of woodworking. In fact, he wisely offloaded a lot of the dead tree cutting and shaping to the burly gentlemen at the local sawmill so he could better focus his efforts on the sparky bits.

At its core, he’s created what’s generally known as a “river table” — a surface made of two or more pieces of live edge wood (that is, a piece of lumber that features at least one uncut edge) that are linked via a band of colored epoxy which looks like flowing water. It’s not uncommon to embed stones or even fake fish in the epoxy to really sell the underwater effect, but this is Plasma Channel we’re talking about, so [Jay] had other ideas.

The first step was hitting up a local neon supplier who could fabricate a pair of neon tubes which roughly followed the shape of his epoxy river. While he was waiting for them to be finished, [Jay] played around with a clever experimental rig that let him determine how thick he could pour the epoxy over the tubes before he lost the capacitive coupling effect he was going for. By embedding a short length of neon tube off-center in a block of epoxy, he could see how the thickness impacted his ability to manipulate the plasma with a wave of his hand just by flipping it over.

With the tube placed on clear standoffs, he was able to position it at the ideal depth for the final epoxy pours. It was around this time that he scattered the remains of his previous projects on the “bottom” of the river, so they can spend the rest of their days looking up at his latest technical triumph. We’re not sure if this is to punish the fallen silicon for giving up early or to honor their sacrifice in the name of progress, but in either event, we respect anyone who keeps a jar of blown components laying around for ritualistic applications.

Once the table was assembled, all that was left was to power the thing. Given his previous projects, [Jay] had no shortage of existing HV supplies to try out. But not being satisfied with anything in the back catalog, he ended up building a new supply that manages to pump out the required amount of juice while remaining silent (to human ears, at least). The unit is powered by a battery pack cleverly embedded into the legs of the table, and is easy to fiddle with thanks to a pulse-width modulation (PWM) module wired hooked to the input. All the components were then held in place with a wide array of custom brackets courtesy of his newly arrived 3D printer.

There’s a lot to love about this project, and more than a few lessons learned. Whether you’re interested in recreating the Tron-like effect of the neon tubes, or have been contemplating your own epoxy-pour worktable and want to see how a first-timer tackles it, this video is a great resource.

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A transparent blue resin waterfall tabletop with a single wooden leg sits on a grey rug between two grey leather chairs.

Using The Sun To Turn Epoxy Into Furniture

October 29, 2022 by Navarre Bartz 16 Comments

Epoxy resins have been used to make some pretty cool furniture, but since it’s still a relatively new material, makers are still discovering new techniques to work with resin. [Cam] from Blacktail Studio may be the first person to bend fully cured epoxy using nothing but a form and the power of the sun.

Inspired by a friend’s mishap with an epoxy table left out in the sun too long, [Cam] wanted to see if he could purposely bend an epoxy sheet into an interesting shape. The tabletop was poured in sections to give an ombre look before being planed and given a preliminary surface finish. The epoxy sheet was then clamped onto a form made of kerfed plywood and left in direct sunlight on a 104°F (40°C) day. Once the sheet began to deform in the sunlight, ratchet straps and more clamps were added to conform the sheet to the bending form.

After letting the tabletop relax for a few days, [Cam] finished the surface with lots of sanding and an automotive polishing regimen. The epoxy was then attached to a single zebrawood leg to give a very modern-looking, waterfall-esque table.

More interesting projects with resin you might want to check out are this ocean-themed epoxy nightlight, how to degas epoxy on the cheap, or some techniques for cold casting with resin.

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Extreme Espresso, Part 2: An Inductive Water Level Sensor

March 8, 2022 by Dan Maloney 27 Comments

[Mark Smith] must really, really like his coffee, at least judging by how much effort he’s put into tricking out his espresso machine.

This inductive water tank sensor is part of a series of innovations [Mark] has added to his high-end Rancilio Silvia machine — we assume there are those that would quibble with that characterization, but 800 bucks is a lot to spend for a coffee maker in our books. We recently featured a host of mods he made to the machine as part of the “Espresso Connect” project, which includes a cool Nixie tube bar graph to indicate the water level in the machine. That display is driven by this sensor, the details of which [Mark] has now shared. The sensor straddles the wall of the 1.7-liter water tank, so no penetrations are needed. Inside the tanks is a track that guides a copper and PETG float that’s sealed with food-safe epoxy resin.

Directly adjacent to the float track on the outside of the tank is a long PCB with a couple of long, sinuous traces. These connect to an LX3302A inductive sensor IC, which reads the position of the copper slug inside the float. That simplifies the process greatly; [Mark] goes into great detail about the design and calibration of the sensor board, as well as hooking it into the Raspberry Pi Zero that lies at the heart of “Espresso Connect’. Altogether, the mods make for a precisely measured dose of espresso, as seen in the video below.

We’d say this was maybe a bit far to go for the perfect cup of coffee, but we sure respect the effort. And we think this inductive sensor method has a lot of non-caffeinated applications that probably bear exploration.

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PCB Microsurgery Puts The Bodges Inside The Board

December 14, 2021 by Dan Maloney 23 Comments

We all make mistakes, and there’s no shame in having to bodge a printed circuit board to fix a mistake. Most of us are content with cutting a trace or two with an Xacto or adding a bit of jumper wire to make the circuit work. Very few of us, however, will decide to literally do our bodges inside the PCB itself.

The story is that [Andrew Zonenberg] was asked to pitch in debugging some incredibly small PCBs for a prototype dev board that plugs directly into a USB jack. The six-layer boards are very dense, with a forest of blind vias. The Twitter thread details the debugging process, which ended up finding a blind via on layer two shorted to a power rail, and another via shorted to ground. It also has some beautiful shots of [Andrew]’s “mechanical tomography” method of visualizing layers by slowly grinding down the surface of the board.

[Andrew] has only tackled one of the bodges at the time of writing, but it has to be seen to be believed. It started with milling away the PCB to get access to the blind via using a ridiculously small end mill. The cavity [Andrew] milled ended up being only about 480 μm by 600 μm and only went partially through a 0.8-mm thick board, but it was enough to resolve the internal short and add an internal bodge to fix a trace that was damaged during milling. The cavity was then filled up with epoxy resin to stabilize the repair.

This kind of debugging and repair skill just boggles the mind. It reminds us a bit of these internal chip-soldering repairs, but taken to another level entirely. We can’t wait to see what the second repair looks like, and whether the prototype for this dev board can be salvaged.

Thanks to [esclear] for the heads up on this one.

The Ins And Outs Of Casting Lenses From Epoxy

December 9, 2021 by Dan Maloney 10 Comments

If you need a lens for a project, chances are pretty good that you pick up a catalog or look up an optics vendor online and just order something. Practical, no doubt, but pretty unsporting, especially when it’s possible to cast custom lenses at home using silicone molds and epoxy resins.

Possible, but not exactly easy, as [Zachary Tong] relates. His journey into custom DIY optics began while looking for ways to make copies of existing mirrors using carbon fiber and resin, using the technique of replication molding. While playing with that, he realized that an inexpensive glass or plastic lens could stand in for the precision-machined metal mandrel which is usually used in this technique. Pretty soon he was using silicone rubber to make two-piece, high-quality molds of lenses, good enough to try a few casting shots with epoxy resin. [Zach] ran into a few problems along the way, like proper resin selection, temperature control, mold release agent compatibility, and even dealing with shrinkage in both the mold material and the resin. But he’s had some pretty good results, which he shares in the video below.

[Zach] is clear that this isn’t really a tutorial, but rather a summary of the highs and lows he experienced while he was working on these casting methods. It’s not his first time casting lenses, of course, and we doubt it’ll be his last — something tells us he won’t be able to resist trying this all-liquid lens casting method in his lab.

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