Author: Dan Maloney

3373 Articles

Have Yourself A Recursive Little Christmas: Ornament That Prints Ornaments

December 24, 2018 by 10 Comments

Sure there are the occasional functional Christmas tree ornaments; we had one that plugged into the lights and was supposed to sound like a bird gently trilling its song, but was in fact so eardrum-piercing that we were forbidden from using it. But in general, ornaments are just supposed to be for looks, right? Not so fast — this 3D-printed ornament has a 3D-printer inside that prints other ornaments. One day it might just be the must-have in functional Christmas decor.

Given that [Sean Hodgins] had only a few days to work on this tree-dwelling 3D-printer, the questionable print quality and tiny print volume can be overlooked. But the fact that he got this working at all is quite a feat. We were initially surprised that he chose to build a stereolithography (SLA) printer rather than the more common fused deposition modeling (FDM) printer, but it makes sense. SLA only requires movement in the Z-axis, provided in this case by the guts of an old DVD drive. The build platform moves in and out of a tiny resin tank, the base of which has a small LCD screen whose backlight has been replaced by a bunch of UV LEDs. A Feather M0 controls the build stage height and displays pre-sliced bitmaps on the LCD, curing the resin in the tank a slice at a time.

Results were mixed, with the tiny snowflake being the best of the bunch. For a rush job, though, and one that competed with collaborating on a package-theft deterring glitter-bomb, it’s pretty impressive. Here’s hoping that this turns into a full-sized SLA build like [Sean] promises.

Continue reading “Have Yourself A Recursive Little Christmas: Ornament That Prints Ornaments” →

Ambitious Homebrew X-Ray Machine Reveals What Lies Within

December 24, 2018 by 31 Comments

We’re not quite sure what to say about this DIY X-ray machine. On the one hand, it’s a really impressive build, with incredible planning and a lot of attention to detail. On the other hand, it’s a device capable of emitting dangerous doses of ionizing radiation.

In the end, we’ll leave judgment on the pros and cons of [Fran Piernas]’ creation to others. But let’s just say it’s probably a good thing that a detailed build log for this project was not provided. Still, the build video below gives us the gist of what must have taken an awfully long time and a fair amount of cash to pull off. The business end is a dental X-ray tube of the fixed anode variety. We’ve covered the anatomy and physiology of these tubes previously if you need a primer, but basically, they use a high voltage to accelerate electrons into a tungsten target to produce X-rays. The driver for the high voltage supply, which is the subject of another project, is connected to a custom-wound transformer to get up to 150V, and then to a voltage multiplier for the final boost to 65 kV. The tube and the voltage multiplier are sealed in a separate, oil-filled enclosure for cooling, wisely lined with lead.

The entire machine is controlled over a USB port. An intensifying screen converts the X-rays to light, and the images of various objects are quite clear. We’re especially impressed by the fluoroscopic images of a laptop while its hard drive is seeking, but less so with the image of a hand, presumably [Fran]’s; similar images were something that [Wilhelm Röntgen] himself would come to regret.

Safety considerations aside, this is an incredibly ambitious build that nobody else should try. Not that it hasn’t been done before, but it still requires a lot of care to do this safely.

Continue reading “Ambitious Homebrew X-Ray Machine Reveals What Lies Within” →

LEDs And Pi Let You Virtually Decorate This Online Christmas Tree

December 23, 2018 by 6 Comments

Anyone who has decorated a Christmas tree knows that the lights are what really make the look. But no matter how many strings you wrap around it, there never seems to be enough. Plus the standard sets either sit there and do nothing, or just blink on and off at regular intervals. Yawn.

But hackers aim higher, and [leo.currie]’s interactive “paintable” Christmas tree takes the lighting game a step beyond. The standard light strings are replaced with strings of WS2811 RGB LEDs which are wired to an ESP8266. A camera connected to a Raspberry Pi is setup up to stream images of the tree to all and sundry on the Interwebz, but with a special twist: it also creates a map of every light on the tree. That allows the lights to be controlled individually in response to user inputs on a web page hosted on the Pi. The upshot is that you can paint the tree with any color you like in real time, or upload various animated GIFs to display on the tree. You can play with the tree directly, or watch a replay on the video below when that Pi inevitably gets hugged to death.

Imagine the possibilities with this. Why not hang a lot of LED strings vertically from the eaves of your house and make a huge, low-resolution display? We’ve featured plenty of large, interactive LED Christmas displays before, and we’d love to see what you come up with.

Continue reading “LEDs And Pi Let You Virtually Decorate This Online Christmas Tree” →

Microcontroller And IMU Team Up For Simple Flight Sim Controls

December 23, 2018 by 3 Comments

Classes are over at Cornell, and that means one thing: the students in [Bruce Land]’s microcontroller design course have submitted their final projects, many of which, like this flight control system for Google Earth’s flight simulator, find their way to the Hackaday tips line.

We actually got this tip several days ago, but since it revealed to us the previously unknown fact that Google Earth has a flight simulator mode, we’ve been somewhat distracted. Normally controlled by mouse and keyboard, [Sheila Balu] decided to give the sim a full set of flight controls to make it more realistic. The controls consist of a joystick with throttle, rudder pedals, and a small control panel with random switches. The whole thing is built of cardboard to keep costs down and to make the system easy to replicate. Interestingly, the joystick does not have the usual gimbals-mounted potentiometers to detect pitch and roll; rather, an IMU mounted on the top of the stick provides data on the stick position. All the controls talk to a PIC32, which sends the inputs over a serial cable to a Python script on the PC running Google Earth; the script simulates the mouse and keyboard commands needed to fly the sim. The video below shows [Sheila] taking an F-16 out for a spin, but despite being a pilot herself since age 16, she was curiously unable to land the fighter jet safely in a suburban neighborhood.

[Bruce]’s course looks like a blast, and [Sheila] clearly enjoyed it. We’re looking forward to the project dump, which last year included this billy-goat balancing Stewart platform, and a robotic ice cream topping applicator.

Continue reading “Microcontroller And IMU Team Up For Simple Flight Sim Controls” →

FPGA Emulates A PDP-1, Breathes New Life Into Classic Video Game

December 21, 2018 by 17 Comments

If you’ve ever wanted to sit at the console of the machine that started the revolution in interactive computing, your options are extremely limited. Of the 53 PDP-1 machines that Digital Equipment Corporation made, only three are known to still exist, and just one machine is still in working order at the Computer History Museum. So a rousing game of Spacewar! on the original hardware is probably not something to put on your bucket list.

But thanks to [Hrvoje], there’s now an FPGA emulation of the PDP-1 that lets you play the granddaddy of all video games without breaking into the CHM. The project was started simply to give [Hrvoje] a sandbox for learning FPGAs and Verilog, but apparently went much further than that. The emulation features the complete PDP-1 instruction set, 4kB of core memory, and representations of the original paper tape reader, teletype, operator’s console, and the classic Type 30 CRT. All the hardware is displayed on a standard HDMI monitor, but it’s the CRT implementation that really sells this. The original Type 30 monitor used a CRT from a radar set, and had long-persistence phosphors that gave the display a very distinctive look. [Hrvoje] replicated that by storing each pixel as three values (X, Y, and brightness) in a circle of four chained shift registers. As the pixels move through the shift registers, the brightness value is decreased so it slowly fades. [Hrvoje] thinks it doesn’t look quite right, but we’ll respectfully disagree on that point.

We’ve argued before that the PDP-1 is the machine that started hacker culture, and we think this project is a fitting tribute to the machine as we enter the year in which it will turn sixty. Having the chance to play with it through this emulation is just icing on its birthday cake.

Continue reading “FPGA Emulates A PDP-1, Breathes New Life Into Classic Video Game” →

Woodworker Goes From 3D-Printing Skeptic To Believer

December 20, 2018 by 30 Comments

If there’s one place where the old ways of doing things live a longer life than you’d otherwise expect, it’s the woodshop. Woodworkers have a way of stubbornly sticking to tradition, and that usually works out fine. But what does it take to change a woodworker’s mind about a tool that seems to have little role in the woodshop: the 3D-printer?

That’s the question [Marius Hornberger] asked himself, and at least for him, there are a lot of woodworking gadgets that can be 3D-printed. [Marius] began his journey into additive manufacturing three years ago as a skeptic, not seeing how [Benchy] and friends could be of any value to his endeavors. But as is often the case with a tool that can build almost anything, all it takes is a little ingenuity to get started. His first tool was a pair of soft jaws for his bench vise. This was followed by a flood of useful doodads, including a clever center finder for round and square stock, custom panels for electrical switches, and light-duty pulleys for some of the machines he likes to build. But [Marius] obviously has an issue with dust, because most of his accessories have to do with helping control it in the shop. The real gem of this group is the hose clamp for spiral-reinforced vacuum hose; standard band clamps don’t fit well on those, but his clamps have an offset that straddles the wire for a neat fit. Genius!

[Marius] has kindly made all his models available on Thingiverse, so feel free to dig in and start kitting out your shop. Once you do maybe you can start building cool things like his all-wood scissors lift.

Continue reading “Woodworker Goes From 3D-Printing Skeptic To Believer” →

Lighting Up The Night Sky With A Flying POV Display

December 19, 2018 by 14 Comments

We’ve seen loads of persistence of vision displays before, but this sky-writing POV display seems as though it may be a first. And we have to agree with its creators that it’s pretty cool.

The idea man on this was [Ivan Miranda], who conceived of a flying POV as a twist on his robotic dot-matrix beach printer. But without any experience in RC flight, he turned to fellow YouTuber [Tom Stanton], whose recent aerial builds include this air-powered plane, for a collaboration. [Ivan]’s original concept was a long strip of Neopixels that would be attached to the underside of a wide-wingspread plane. WIthout much regard for the payload limits of most RC planes, he came up with a working display that was 3 meters long. His video below shows it in use in his shop, with some pretty impressive long exposure images.

[Tom]’s part was to make the POV display flyable. He cut the length down to 2 meters and trimmed the weight enough to mount it to a quadcopter. Ungainly as the machine was, he was able to master its control enough to start painting pictures across the twilight sky. The images at the end of his video are actually stunning – we’re especially fond of Thunderbird 2, which takes us back to our childhood.

We’re not sure what the practical uses of this are, but that’s hardly the point. It’s enough that it’s an interesting project from an unlikely duo. Continue reading “Lighting Up The Night Sky With A Flying POV Display” →