Beautifully documented, modular, and completely open-source, this split flap display project by [JON-A-TRON] uses 3D printing, laser cutting and engraving, and parts anyone can find online to make a device that looks as sharp as it is brilliantly designed. Also, it appears to be a commentary on our modern culture since this beautifully engineered, highly complex device is limited to communicating via three-letter combos and cat pictures (or cat video, if you hold the button down!) As [JON-A-TRON] puts it, “Why use high-resolution, multi-functional devices when you can get back to your industrial revolution roots?” Video is embedded below.
Does it ever just kill you that someone in a factory somewhere got to have all the fun of assembling your bench tools? There are a lot of questionable circuit boards floating around the Internet, and they can replicate practically any section of a circuit. When it comes to putting a prototype these days you can pretty much just buy each block of your system’s overview flowchart and string them together. [GreattScott!] combines a few of these into a relatively useful variable power supply with current limiting.
Admittedly, this is more of academic exercise if your only metric for success is monetary savings. Comparable power supplies can be purchased for the same amount of local currency as the parts in this build. However, there is something to be said for making it yourself.
The core of this build is based around the LTC3780, a bit of silicon from LT that offers both buck and boost converting along with a current control mode. It’s useful for a lot of things. The here is rated for up to 130 watts of power, which makes is a decent amount of power for a bench supply.
With a few modifications, like replacing the world’s most untrustworthy potentiometers and adding a nice ABS box, the build is completed. Along the way, [GreatScott!] offers a few tricks for testing and some reminders of how not to make yourself dead when playing with electricity.
The end is a working lab bench supply project that can easily keep a hacker entertained on a lazy Sunday afternoon.
We’ll just come out and say it, [reboots] has friends with nice garbage. Sure, some of us have friends who are desperately trying to, “gift,” us a CRT monitor, hope dropping like a rock into their stomach when they realize they can’t escape the recycling fee. [reboots] has friends who buy other people’s poorly thought out CNC projects and then gift him with the parts.
After dismantling the contraption he found himself with nice US and Japanese made linear motion components. However, he needed a CNC controller to drive it all. So he helped another friend clean out their garage and came away with a FlashCut CNC controller.
Now that he had a controller and the motion components whirring nicely, he really needed a frame to put it all in. We like to imagine that he was at a friend’s barbeque having a beer. In one corner of the yard was an entire Boeing 747. A mouldering scanning electron microscope with a tattered and faded blue tarp barely covering its delicate instrumentation sat in another corner. Countless tech treasures were scattered about in various states. It was then that he spotted a rusting gamma ray spectrometer in the corner that just happened to have the perfect, rigid, gantry frame for his CNC machine.
Of course, his friend obliged and gladly gave up the spectrometer. Now it was time to put all together. The gantry was set on a scavenged institutional door. The linear motion frames were bolted in place. Quite a few components had to be made, naturally, of scrap materials.
Most people will start by using a handheld router for the spindle. The benefits are obvious: they’re inexpensive, easy to procure, and generally come with mounts. But, there are some definite downsides, one of the most glaring of which is the lack of true speed control.
Even routers that allow you to adjust the speed (a fairly common feature on new models) generally don’t actually regulate that speed. So, you end up with a handful of speed settings which aren’t even predictable under load. Furthermore, they usually rely on high RPMs to do their work. For those reasons, handheld woodworking routers aren’t the best choice for a mill that you intend to cut metal with.
[reboots] noticed this problem while building this machine and came up with an inexpensive way to build a speed-controlled spindle. His design uses a brushless DC motor, controlled through a hobby ESC (electronic speed control), which uses a belt to drive the spindle. The spindle itself is mounted using skateboard bearings, and ends in an E11 collet (suitable for light machining in aluminum).
With the ESC providing control of the brushless motor, he’s able to directly control the spindle speed via software. This means that spindle speeds can be changed with G-code, allowing for optimized feeds and speeds for different operations. The belt-drive increases torque while separating the motor from the spindle, which should keep things cool, and reduce rotating mass on the spindle itself. Now all [reboots] needs to do is add a DIY tool changer!
Virtual reality doesn’t feel very real if your head is the only thing receiving the virtual treatment. For truly immersive experiences you must be able to use your body, and even interact with virtual props, in an intuitive way. For instance, in a first-person shooter you want to be able to hold the gun and use it just as you would in real reality. That’s exactly what [matthewhallberg] managed to do for just a few bucks.
This project is an attempt to develop a VR shooting demo and the associated hardware on a budget, complete with tracking so that the gun can be aimed independent of the user’s view. [matthewhallberg] calls it The Oculus Cardboard Project, named for the combined approach of using a Google Cardboard headset for the VR part, and camera-based object tracking for the gun portion. The game was made in Unity 3D with the Vuforia augmented reality plugin. Not counting a smartphone and Google Cardboard headset, the added parts clocked in at only about $15.
Using corrugated cardboard and a printout, [matthewhallberg] created a handheld paddle-like device with buttons that acts as both controller and large fiducial marker for the smartphone camera. Inside the handle is a battery and an ESP8266 microcontroller. The buttons on the paddle allow for “walk forward” as well as “shoot” triggers. The paddle represents the gun, and when you move it around, the smartphone’s camera tracks the orientation so it’s possible to move and point the gun independent of your point of view. You can see it in action in the video below.
Tracking a handheld paddle with a fiducial marker isn’t a brand new idea; We were able to find this project for example which also very cleverly simulates a trigger input by making a trigger physically alter the paddle shape when you squeeze it. The fiducial is altered by the squeeze, and the camera sees the change and registers it as an input. However, [matthewhallberg]’s approach of using hardware buttons does allow for a wider variety of reliable inputs (move and shoot instead of just move, for example). If you’re interesting in trying it out, the project page has all the required details and source code.
This isn’t [matthewhallberg]’s first attempt and getting the most out of an economical Google Cardboard setup. He used some of the ideas and parts from his earlier DIY Virtual Reality Snowboard project.
A VMC (vertical machining center) is essentially a CNC vertical milling machine on steroids. Many CNC mills are just manual milling machines that have been converted to CNC control. They work nicely, but have a number of drawbacks when it comes to real world CNC milling: manual tool changes, lack of chip collection, lack of coolant containment, and backlash issues (which a manual machinist normally compensates for).
These problems are solved with a VMC, which will usually have an automatic tool changer, and an enclosure to contain coolant and wash chips down into a collection pan. They are, however, very expensive, very big, and very heavy. Building one from scratch is a massive undertaking, but one which [Chris DePrisco] was brave enough to take on.
Want to get somewhere safely, but all you have is a Segway? An afternoon spent tinkering can turn your Segway into a lounging cruiser with this hoverseat attachment, just like YouTuber [Inflatable Boats]’s hot new ride.
The backbone of the cart is the Segway Mini Pro. An aluminium frame attaches to the Segway via an eye-bolt and two carabiners, the larger of which has some tape wrapped around it to reduce wear. A swivel caster is attached with u-bolts to support the weight of the rider along the middle of this makeshift go-cart. Pushing on a t-handle made of pvc — connected to the Segway’s knee brace with a simple strap — engages the motor in lieu of the normal lean-to-go-forward action. Turning is simply done by swinging the handle or pressing with your feet.
DIY medical science is fun stuff. One can ferret out many of the electrical signals that make the body run with surprisingly accessible components and simple builds. While the medical community predictably dwells on the healthcare uses of such information, the hacker is free to do whatever he or she wants.
A good first start is to look at the relatively strong electrical signals coming off of the heart and other muscles. [Bernd Porr] has put together a simple bioamplifier circuit, and his students have made a series of videos explaining its use that’s well worth your time if you are interested in these things.
Continue reading “All About Biosignals”