Recovering Nichrome Wire From Unexpected Sources

April 10, 2014 by James Hobson 41 Comments

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Don’t you hate it when you’re in a pinch and all your favorite surplus or electronic stores are closed? You’ve gotta finish this project, but how? He’s a nice real hack for you guys. How to recover nichrome wire from a ceramic heater!

Necessity spawned this idea, as [Armilar] needed to make 45 cuts in two pieces of foam in order to ship some long circuit boards. Not wanting to make the 90 cuts individually, he improvised this nichrome slicing jig. Not having a spool of nichrome handy, he decided to use a less conventional method. He pulled out a sledgehammer and smashed open a ceramic wirewound resistor.

According to him, nice big ceramic resistors like this 10W one have about a meter of nichrome wire inside! After breaking the ceramic, it’s quite easy to remove. He made up a jig using nylon spacers and rivets, and then wrapped his wire back and forth across the whole length. It worked perfectly — though he was using 240VDC @ about 1.2A…

If you don’t need such a complex setup, there’s always the bare bones wire foam cutters we’ve featured many times before.

Turning An Analog Scope Into A Logic Analyzer

April 9, 2014 by Brian Benchoff 9 Comments

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When [Marco] was planning on a storage oscilloscope build, he realized having a small device to display eight digital signals on an analog scope would be extremely useful. This just happens to be the exact description of a simple logic analyzer and managed to turn his idea into a neat little project (German, Google translation).

The theory of operation for this surprisingly simple, and something that could be completed in a few hours with a reasonably well stocked hackerspace or parts drawer in a few hours. A clock generator and binary counter are fed into the lower three bits of a simple R2R DAC, while the 8 inputs are fed into an 8-input multiplexer and sent to the last bit of the DAC. With nothing connected to the logic analyzer inputs, the output to the scope would just be an 8-step ramp that would appear as eight horizontal lines on the screen. With something connected to the logic analyzer input, an extremely primitive but still very useful logic analyzer appears on the screen.

While it’s not the greatest analyzer, it is something that can be cobbled together in an hour or two, and the capabilities are more than sufficient to debug a few simple circuits or figure out some timings in a project.

Creative Continuity Tester Made For A Few Bucks

April 6, 2014 by James Hobson 13 Comments

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No multi-meter? For troubleshooting most household things, a continuity tester is extremely handy. And as it turns out, you can make your own from the dollar store for next to nothing.

[Carlyn] shows us how to make two different styles of continuity testers — a light up version using a bicycle light, or a buzzer version using one of those cheap window alarms. The leads are made of 1/8″ audio cables — and everything for both these testers cost less than $5 from their local dollar store. It’s a very simple build process that you can probably figure out just from this one photo, but [Carlyn] has also taken pictures of every step along the way.

Compared to building one of these out of components from Radio Shack, this method is much more MacGyver, and cheap! Hooray for taking advantage of mass produced consumer products!

Not functional enough? How about building a talking multimeter instead? No? Have you ever wanted two multi-meters in one? Say hello to the Mooshimeter!

Arduino Controlled Dahlander Motor Switch

April 2, 2014 by Eric Evenchick 15 Comments

[Jean-Noel] is fixing a broken Lurem woodworking machine. This machine uses a three-phase Dahlander motor, which has three operation modes: stop, half speed, and full speed. The motor uses a special mechanical switch to select the operating mode. Unfortunately, the mechanical bits inside the switch were broken, and the motor couldn’t be turned on.

To solve the problem without sourcing a new switch, [Jean-Noel] built his own Arduino based Dahlander switch. This consists of three relays that select the wiring configuration for each speed mode. There’s also a button to toggle settings, and two lamps to show what mode the motor is currently in.

The Arduino runs a finite-state machine (FSM), ensuring that the device transitions through the modes in the correct order. This is quite important, since the motor could be damaged if certain restrictions aren’t followed. The state machine graph was generated using Fizzim, a free tool that generates not only FSM graphs, but also Verilog and VHDL code for the machines.

The final product is housed in a DIN rail case, which allows it to be securely mounted along with the rest of the wiring. The detailed write-up on this project explains all the details of the motor, and the challenges of building this replacement switch.

Portable SMT Lab For Hacker On The Go

April 2, 2014 by Adam Fabio 31 Comments

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We admit it, we’re suckers for workbenches and toolboxes. [Jon] must feel the same way, because he built this portable surface mount electronics lab. It’s a beast of a project, which might be why it’s project #666 on Hackaday.io. [Jon] spends a lot of time working off site, and keeps finding himself without proper surface mount soldering tools. Ever tried to stack an 0603 resistor with a 40 watt pistol grip iron? Take our word for it, the results are not pretty.

[Jon] started with two cheap aluminum cases from Harbor Freight. He loaded them up with the typical lab supplies: soldering iron, oscilloscope, multimeter, dual lab supplies, and a good assortment of hand tools. He then added a few choice SMT tools: A hot air tool, a good LED light, and a stereo magnifier. Many of the tools are mounted on DIN rail along the rear of the cases. All the low voltage equipment runs on a common 12V bus.

We really like what [Jon] did with the tops of the cases. Each lid contains a plywood sheet. When the cases are opened, the plywood becomes a work surface. As an added bonus, the wood really strengthens the originally flimsy tool cases. The only thing we would add is a good portable anti-static mat.

The final build is really slick. Once the cases are open, four bolts act as feet. The microscope swings out, and the hot air gun hangs on the right side. Plug in power and you’ve gone from zero to SMT hero in under 1 minute.

Reflowing With A Hair Straightener

March 30, 2014 by Brian Benchoff 34 Comments

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Around here, reflow ovens usually mean a toaster oven, and if you’re exceptionally cool, a thermistor and PID controller. There are, of course, a thousand ways to turn solder paste into a solid connection and [Saar] might have found the cheapest way yet: a hair straightener with a street value of just £15.

We don’t expect the majority of the Hackaday demographic to know much about hair straighteners, but [Saar] has done all the work and came up with a list of what makes a good one. Floating plates are a must to keep the PCB in contact with the heating element at all times, and temperature control is essential. [Saar] ended up with a Remington S3500 Ceramic Straight 230 Hair Straightener, although a trip to any big box store should yield a straightener that would work just as well.

One modification [Saar] added was a strip of Kapton tape to one of the ceramic heating elements. It’s not a replacement for a toaster oven or real reflow oven, but for small boards it works just as well.

Video below.

Continue reading “Reflowing With A Hair Straightener” →

Hacking A Laser Tape Measure In 3 Easy Steps

March 29, 2014 by Adam Fabio 7 Comments

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[Andrew] got a little help from his friends to hack a laser distance meter. Using laser distance meters as sensors is one of the great quests of hackers – with good reason. Accurate distance readings are invaluable for applications including robots, printers, and manufacturing. We’ve seen people try and fail to hack similar units before, while others built their own from scratch. [Andrew] started experimenting with the UNI-T 390B, a relatively cheap ($60 USD) device from China. He found the 390B has a serial port accessible through its battery compartment. Even better, the serial port is still enabled and outputs distance data. While data could be read, [Andrew] couldn’t command the 390B to start a measurement. The only option seemed to be using the Arduino to simulate button presses on the 390B’s front panel.

In an update to his original blog, he described an Arduino sketch which would decode the distance measurements. That’s when [speleomaniac] jumped in with the discovery that the Uni-T would respond to commands in the form “*xxxxx#”. Armed with this information, [Andrew] posted a second update with a basic command breakdown. Command *00004# will take a single measurement and output the data via serial. Command *00002# will take 3 measurements, outputting them in a C style array format. There are several other commands which output debug information and what appear to be stored measurement dumps. Although he didn’t explore every nuance of the data output, [Andrew] now has enough information to initiate a measurement and read the result. Nice work!

[Thanks James!]