Misc Hacks

4032 Articles

Using Additives For Better Performing Epoxy

March 17, 2020 by 13 Comments

Epoxy resins are an important material in many fields. Used on their own as an adhesive, used as a coating, or used in concert with fiber materials to make composites, their high strength and light weight makes them useful in many applications. [Tech Ingredients] decided to explore how combining basic epoxy resin with various additives can make it perform better in different roles.

The video primarily concerns itself with explaining different common additives to epoxy resin mixtures, and how they impact its performance. Adding wood flour is a great way to thicken epoxy, allowing it to form a bead when joining two surfaces. Microbeads are great to add if you’re looking to create a sandable filler. Other additive like metal powders lend the mixture resistance to degradation from UV light, while adding dendritic copper creates a final product with high thermal conductivity.

The video does a great job of not only explaining the additives and their applications, but also shares a few handy tips on best workshop practices. Things like triple-gloving and observing proper mixing order can make a big difference to your workflow and lead to better results.

We’ve seen practical applications of epoxy mixes before – with epoxy granite being a particularly popular material. Video after the break.

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Hot Wire Ribbon Cutter Ceremoniously Heats Up Productivity

March 16, 2020 by 8 Comments

Anyone who’s ever cut ribbon, grosgrain or otherwise, may be dismayed by the frayed edge. There are methods of avoiding this, like cutting the ribbon diagonally, or double-diagonally into a forked point, or cutting it straight across and cauterizing the threads with a lighter. But if you have a thirteen dozen baker’s dozens’ worth of goodies to festoon, ain’t nobody got time for that.

[IgorM92] made this hot wire ribbon cutter for his wife, who has a yummy-looking baking business. It combines the cutting and the heat-sealing into a single step by using the heating element from an old soldering iron. If you don’t have one of those, you could just as easily use the nichrome wire from an old hair dryer, a toaster, or wire-wound resistor.

Since the idea is essentially shorting a power source to heat up a wire, it should be done safely. [IgorM92] used a phone charger to condition mains power down to 5 V. There isn’t much else to the circuit, just a rocker switch, a power-indicating LED, and its resistor, but this simple project will no doubt save a lot of time and labor. Burn past the break to watch it ramp up production.

Nichrome wire is good for cutting foam, too. Here’s a bare-bones version that can be made in minutes.

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Digital Designer Teaches High School

March 15, 2020 by 6 Comments

We wish we had met [Mr. Mueller] when we were in high school. After 20 years as a digital design engineer, he decided to teach a digital electronics class at the high school level at LASA high school in Austin, Texas. He’s been doing it for seven years and has made his course material available via Google Docs.

Don’t let the high school level fool you. Topics range from simple electronics to Spice. There’s coverage of discrete devices, oscilloscopes, and Arduinos. There’s plenty of digital logic, of course, and a simple 16-bit microprocessor, too. There are labs for FPGAs using Verilog and talks about ARM. It’s pretty comprehensive and we wonder if they can really cram all this into a single school year. One thing we saw that caught our eye was the simulation of a transistor using Play-Doh. Turns out it isn’t an electrical simulation, but a simulation of how photolithography creates transistors. Still good stuff.

This would be great for teaching students of pretty much any age, even if you took only parts of it. It would also be worthwhile for self-study. We know how much work it takes to put something like this together, and we can’t commend [Mr. Mueller] and the LASA high school enough for making it available to everyone.

There is more and more course material out there at all levels and we think that’s a great thing. If you need something for a younger set, try a blindfold.

One Anti-Static Ring To Delight Them All

March 12, 2020 by 17 Comments

What’s the worst thing about winter? If you’re as indoorsy as we are, then static electricity is probably pretty high on the list. It can ruin your chips, true, but you always wear a wrist ground strap when you handle those, right? But away from the bench, every doorknob and light switch is lying in wait, ready to shock you. If you had an anti-static ring like [LaPuge], you could be watching a tiny neon bulb light up instead of the air between your poor finger and the discharge point.

The ring itself is printed in TPU 95A filament for comfort and flexibility. There isn’t a whole lot to the circuit, just a neon bulb, a 1MΩ resistor, and some copper tape, but this piece of functional jewelry has the potential to spark up plenty of charged conversations. Zap your way past the break to see it light up against a door handle.

If you want to light up neon bulbs all year long, build a field of them and wave them near your Tesla coil!

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Build Your Own Mouse For High Performance

March 12, 2020 by 12 Comments

For the dedicated gamer or hardcore computer user, there’s plenty of options for high-end input peripherals. We’ve seen plenty of makers build their own bespoke keyboards, too. Less commonly seen are custom mice, but [gipetto TranquilTempest] has crafted just such a device to suit their tastes.

The mouse is based on the PMW3360 sensor, prized for its 250 inch per second speed and 50g acceleration capability. Buttons are read by an ATMEGA32U4 which handles hardware debouncing for improved control. Anyone that’s accidentally double-clicked all their villagers in AOE II can appreciate this feature. There’s also specialised code to read the wheel encoder from [Ben Buxton] which helps avoids backscrolling.

The PCB was ordered from JLCPCB using their assembly service, which comes in handy for makers who want to build advanced designs without messing around with reflow. It’s designed to fit inside Microsoft mouse shells popular in years past – like the Wheel Mouse Optical and the Intellimouse 1.3.

Building your own mouse from the ground up is a great way to get yourself an input device that perfectly serves your needs. We’ve seen others work in the field, with custom trackballs and breakout boards for sensors. If you’ve got your own cutting edge build, be sure to let us know!

Chip Decapping The Easy Way

March 11, 2020 by 27 Comments

Chip decapping videos are a staple of the hacking world, and few things compare to the beauty of a silicon die stripped of its protective epoxy and photographed through a good microscope. But the process of actually opening that black resin treasure chest seems elusive, requiring as it does a witch’s brew of solvents and acids.

Or does it? As [Curious Marc] documents in the video below, a little heat and some finesse are all it takes, at least for some chips. The method is demonstrated by [Antoine Bercovici], a paleobotanist who sidelines as a collector of old chips. After removing chips from a PCB — he harvested these chips from an old PlayStation — he uses hot air to soften the epoxy, and then flexes the chip with a couple of pairs of pliers. It’s a bit brutal, but in most of the Sony chips he tried for the video, the epoxy broke cleanly over the die and formed a cleavage plane that allowed the die to be slipped out cleanly. The process is not unlike revealing fossils in sedimentary rocks, a process that he’s familiar with from his day job.

He does warn that certain manufacturers, like Motorola and National, use resins that tend to stick to the die more. It’s also clear that a hairdryer doesn’t deliver enough heat; when they switched to a hot air rework station, the success rate went way up.

The simplicity of this method should open the decapping hobby up to more people. Whether you just want to take pretty pictures or if reverse engineering is on your mind, put the white fuming nitric acid down and grab the heat gun instead.

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