Homemade EDM Can Cut Through Difficult Materials Like Magnets With Ease

Many years ago [ScorchWorks] built an electrical-discharge machining tool (EDM) and recently decided to write about it. And there’s a video embedded after the break.

The build is based on the designs described in the book “Build an EDM” by Robert Langolois. An EDM works by creating lots of little electrical discharges between an electrode in the desired shape and a material underneath a dielectric solvent bath. This dissolves the material exactly where the operator would like it dissolved. It is one of the most precise and gentle machining operations possible.

His EDM is built mostly out of found parts. The power supply is a microwave oven transformer rewired with 18 gauge wire to drop the voltage to sixty volts instead of the oven’s original boost to 1.5kV.  The power resistor comes from a dryer element robbed from a unit sitting beside the road. The control board was etched using a hand traced schematic on the copper with a Sharpie.

The linear motion element are two square brass tubes, one sliding inside the other. A stepper motor slowly drives the electrode into the part. Coolant is pumped through the electrode which is held by a little 3D printed part.

The EDM works well, and he has a few example parts showing its ability to perform difficult cuts. Things such as a hole through a razor blade., a small hole through a very small piece of thick steel, and even a hole through a magnet.

Continue reading “Homemade EDM Can Cut Through Difficult Materials Like Magnets With Ease”

DIY Smart Home Device Means No More Fumbling in the Dark

Smart home tech is on the rise, but cost or lack of specific functionality may give pause to prospective buyers. [Whiskey Tango Hotel] opted to design their own system using a Raspberry Pi and Bluetooth device connectivity. Combining two ubiquitous technologies provides a reliable proximity activation of handy functions upon one’s arrival home.

Electrical Wiring Diagram

The primary function is to turn on a strip of LEDs when [Whiskey Tango Hotel] gets home to avoid fumbling for the lights in the dark, and to turn them off after a set time. The Raspberry Pi and Bluetooth dongle detect when a specified discoverable Bluetooth device comes within range — in this case, an iPad — after some time away. This toggles the Pi’s GP10 outputs and connected switching relay while also logging the actions to the terminal and Google Drive via IFTTT.

Continue reading “DIY Smart Home Device Means No More Fumbling in the Dark”

A Grounded Option for the Jet-Setting Homebody

Over the course of 10 years, [Bruce Campbell] has built himself a sleek pad out of a Boeing 727-200 in the middle of the picturesque Oregon countryside.

As you’d expect, there are a number of hurdles to setting up a freaking airplane as one’s home in the woods. Foremost among them, [Campbell] paid $100,000 for the aircraft, and a further $100,000 for transportation and installation costs to get it out to his tract of land — that’s a stiff upfront when compared to a down payment on a house and a mortgage. However, [Campbell] asserts that airplanes approaching retirement come up for sale with reasonable frequency, so it’s possible to find something at a lower price considering the cost of dismantling an airframe often compares to the value of the recovered materials.

Once acquired and transported, [Campbell] connected the utilities through the airplane’s existing systems, as well going about modifying the interior to suit his needs — the transparent floor panels are a nice touch! He has a primitive but functional shower, the two lavatories continue to function as intended, sleeping, dining and living quarters, and a deck in the form of the plane’s wing.

Continue reading “A Grounded Option for the Jet-Setting Homebody”

How To Keep An Unruly Dryer In Line

If necessity is the mother of invention, then inconvenience is its frustrating co-conspirator. Faced with a finicky dryer that would shut down mid-cycle with a barely audible beep if its load was uneven (leaving a soggy mass of laundry), [the0ry] decided to add the dryer to the Internet of Things so it could send them an email whenever it shut itself down.

After opening a thinger.io account, adding the soon-to-be device, and setting up the email notification process, [the0ry] combined the ESP8266 Development Board, a photosensitive resistor, and a 5V power supply on a mini breadboard. All that was left was to mount it on the dryer and direct the LDR (light-dependent resistor) to the machine’s door lock LED to trigger an email when it turned off — indicating the cycle had finished or terminated prematurely. A little tape ensured the LDR would only be tripped by the desired light source.

If you’re an apartment-dweller have WiFi in the wash area it would be awesome to see a battery-powered version you take with you. But in general this is a great hardware blueprint as many device have status LEDs that can be monitored in a similar way. If you want to keep the server in-house (literally in this case) check out the Minimal MQTT series [Elliot Williams] recently finished up. It uses a Raspberry Pi as the center server and an ESP8266 is one of the limitless examples of hardware that plays nicely with the protocol.

We love seeing hacks like this because not only does it conserve water and energy by reducing instances of rewashing, but it’s also a clever way to extend the life of an appliance and potentially save hundreds of dollars in replacing it. Add this to the bevvy of hacks that add convenience to one’s home — some of which produce delicious results.

Turn Down the Bed, Turn Down the Lights

Home automation seems to be working its way to a computer-controlled future in which humans will be little more than an afterthought. Eventually they will take over Skynet-style, but until then, we will enjoy the relative comfort that a good home automation project provides. The latest from [Clement] certainly goes a long way towards this goal by automating his bed (Google Translate from French).

With four load cells and a microcontroller, [Clement]’s bed can tell whether or not he is sleeping. After taking a weight reading, the bed can send commands to the rest of his home automation system and tell it to turn off his stereo and turn the lights off in the house (or change them to a different color). And it doesn’t stop with just going to bed, but when he wakes up as well. The system can begin turning on lights, starting the coffee machine, and opening the blinds without any interaction from him at all.

This project goes well beyond simple home automation. With a little configuration and extrapolation, [Clement] can tell where in the bed he slept at night, what stages of sleep he was in at specific times, and the overall quality of his sleep. This could go a long way for someone who has a hard time sleeping and needs a little more information on how to correct the problem.

While we’ve seen various takes on tying a bed into one’s home automation system, this one goes above and beyond with the amount of data collected. You could even go one step further and have it turn on some Barry White if the normal weight in the bed suddenly doubles, for whatever reason. Maybe that will be a feature in Version 2.

Small Experiments in DIY Home Security

[Dann Albright] writes about some small experiments he’s done in home security.

He starts with the simplest. Which is to purchase an off the shelf web camera, and hook it up to software built to do the task. The first software he uses is the free, iSpy open source software. This adds basic features like motion detection, time stamping, logging, and an interface. He also explores other commercial options.

Next he delves a bit deeper. He starts by making a simple motion detector. When the Arduino detects motion using a PIR sensor it gets a computer to text an alert. After the tutorial begins to veer a little and he adds his WiFi light bulbs to the mix. Now he can send an email and change the color of the lights.

We suppose, that from a security standpoint. It would really freak a burglar out if all the lights turned red when they walked into a room. Either way, there’s definitely a fun weekend project in playing around with all these systems.

Add Bluetooth to a Cheap Electronic Lock

[James] works from home. His office is filled with objects that can be described with adjectives such as, “expensive,” and, “breakable.” His home, however, is filled with professional object-breakers known as children. To keep these two worlds from colliding, he installed a keypad lock on his office door. The potential side-effect of accidentally training his children to be master safe-crackers aside, the system seems to work so far.

However, being a hacker, the tedium of entering a passcode soon grew too heavy for him. Refusing to be a techno-peasant, he set out to improve his lock. The first step was to reverse engineer the device. The lock is divided into two halves, one has a keypad and handle, the other actually operates the lock mechanism. They are connected with a few wires. He hooked an oscilloscope to the most likely looking candidates, and looked at the data. It was puzzling at first, until he realized one was a wake-up signal, and the other was the data. He then hooked the wires up to a Bluetooth-enabled Arduino, and pressed buttons until he had all the serial commands the door lock used.

After that it was a software game. He wrote code for his phone and the Arduino to try out different techniques and work out bugs. Once he had that sorted, he polished the app and code until he reached his goal. All of the code is available on his GitHub.

Finally, through his own hands, he elevated himself from techno-peasant to wizard. He need but wave his pocket oracle over the magic box in front of his wizard’s lair, and he will be permitted entry. His wizardly trinkets secure from the resident orcs, until they too begin their study of magic.