Ingenious use of 3D Printer gives Simba the Mane he deserves

February 13, 2017 by Adil Malik 7 Comments

Here at Hackaday, we love clever 3D prints. This amazing lion statue remixed by [ _primoz_], makes us feel no different. It is no secret that FDM 3D printers have come a long way, propelled by the enthusiastic support from the open source community.

However, FDM 3D printers have some inherent limitations; some of which arise from a finite print nozzle diameter, tracing out the 3D object layer by layer. Simply put, some print geometries and dimensions are just unattainable. We discussed the solution to traditional FDM techniques being confined to Planer layers only in a previous article.

The case in point here is a 3D printed lion whose original version did not fully capture its majestic mane. [_primoz_] solution was to construct a support cylinder around the head and form the actual hair as a series of planar bristles, which were one extrusion wide.

This was followed by some simple post processing, where a heat gun was used to form the bristles into a dapper mane.

The result is rather glorious and we can’t wait for someone to fire up a dual extruder and bring out the flexible filament for this print!

[via Thingiverse]

Spinning 3D POV Display: a High School Term Project

November 16, 2016 by Jenny List 25 Comments

If you are a fan of sci-fi shows you’ll be used to volumetric 3D displays as something that’s going to be really awesome at some distant point in the future. It’s been about forty years since a virtual 3D [Princess Leia] was projected to Star Wars fans from [R2D2]’s not-quite-a-belly-button, while in the real world it’s still a technology with some way to go. We’ve seen LED cubes, spinning arrays, and lasers projected onto spinning disks, but nothing yet to give us that Wow! signaling that the technology has truly arrived.

We are starting to see these displays move from the high-end research lab into the realm of hackers and makers though, and the project we have for you here is a fantastic example. [Balduin Dettling] has created a spinning LED display using multiple sticks of addressable LEDs mounted on a rotor, and driven by a Teensy 3.1. What makes this all the more remarkable is that he’s a secondary school student at a Gymnasium school in Germany (think British grammar school or American prep school).

There are 480 LEDs in his display, and he addresses them through TLC5927 shift registers. Synchronisation is provided by a Hall-effect sensor and magnet to detect the start of each rotation, and the Teensy adjusts its pixel rate based on that timing. He’s provided extremely comprehensive documentation with code and construction details in the GitHub repository, including a whitepaper in English worth digging into. He also posted the two videos we’ve given you below the break.

What were you building in High School? Did it involve circuit design, mechanical fabrication, firmware, and documentation? This is an impressive set of skills for such a young hacker, and the type of education we like to see available to those interested in a career in engineering.

Continue reading “Spinning 3D POV Display: a High School Term Project” →

All Your Displays Are Belong to Us

September 26, 2016 by Elliot Williams 23 Comments

Artist and Hackaday reader [Blair Neal] wrote in with his incredible compendium of “alternative” displays. (Here as PDF.) From Pepper’s Ghost to POV, he’s got it all covered, with emphasis on their uses in art.

There’s an especially large focus on 3D displays. Projecting onto screens, droplets of water, spinning objects, and even plasma combustion are covered. But so are the funny physical displays: flip-dots, pin-cushions, and even servo-driven “pixels”.

We really liked the section on LCDs with modified polarization layers — we’ve seen some cool hacks using that gimmick, but the art pieces he dredged up look even better. Makes us want to take a second look at that busted LCD screen in the basement.

We’re big fans of the bright and blinky, so it’s no surprise that [Blair] got a bunch of his examples from these very pages. And we’ve covered [Blair]’s work as well: both his Wobbulator and his “Color a Sound” projects. Hackaday: your one-stop-shop for freaky pixels.

[Blair]’s list looks pretty complete to us, but there’s always more out there. What oddball displays are missing? What’s the strangest or coolest display you’ve ever seen?

Absolute 3D Tracking With EM Fields

September 20, 2016 by Gerrit Coetzee 28 Comments

[Chris Gunawardena] is still holding his breath on Valve and Facebook surprising everyone by open sourcing their top secret VR prototypes. They have some really clever ways to track the exact location and orientation of the big black box they want people to strap to their faces. Until then, though, he decided to take his own stab at the 3D tracking problems they had to solve.

While they used light to perform the localization, he wanted to experiment with using electromagnetic fields to perform the same function. Every phone these days has a magnetometer built in. It’s used to figure out which way is up, but it can also measure the local strength of magnetic fields.

Unfortunately to get really good range on a magnetic field there’s a pesky problem involving inverse square laws. Some 9V batteries in series solved the high current DC voltage source problem and left him with magnetic field powerful enough to be detected almost ten centimeters away by his iPhone’s magnetometer.

As small as this range seems, it ended up being enough for his purposes. Using the existing math and a small iOS app he was able to perform rudimentary localization using EM fields. Pretty cool. He’s not done yet and hopes that a more sensitive magnetometer and a higher voltage power supply with let him achieve greater distances and accuracy in a future iteration.

Ask Hackaday MRRF Edition: 3D Printers Can Catch Fire

March 21, 2016 by Gerrit Coetzee 79 Comments

[Jay] out of the River City Labs Hackerspace in Peoria, IL cleared out a jam in his printer. It’s an operation most of us who own a 3D printer have performed. He reassembled the nozzle, and in a moment forgot to tighten down the grub nut that holds the heater cartridge in place. He started a print, saw the first layer go down right, and left the house at 8:30 for work. When he came back from work at 10:30 he didn’t see the print he expected, but was instead greeted by acrid smoke and a burnt out printer.

The approximate start time of the fire can be guessed by the height of the print before failure.

As far as he can figure, some time at around the thirty minute mark the heater cartridge vibrated out of the block. The printer saw a drop in temperature and increased the power to the cartridge. Since the cartridge was now hanging in air and the thermistor that reads the temperature was still attached to the block, the printer kept sending power. Eventually the cartridge, without a place to dump the energy being fed to it, burst into flame. This resulted in the carnage pictured. Luckily the Zortrax is a solidly built full metal printer, so there wasn’t much fuel for the fire, but the damage is total and the fire could easily have spread.

Which brings us to the topics of discussion.

How much can we trust our own work? We all have our home-builds and once you’ve put a lot of work into a printer you want to see it print a lot of things. I regularly leave the house with a print running and have a few other home projects going 24/7. Am I being arrogant? Should I treat my home work with a lesser degree of trust than something built by a larger organization? Or is the chance about the same? Continue reading “Ask Hackaday MRRF Edition: 3D Printers Can Catch Fire” →

Using Photogrammetry To Design 3D Printed Parts

February 12, 2016 by Brian Benchoff 33 Comments

[Stefan] is building a fixed wing drone, and with that comes the need for special mounts and adapters for a GoPro. The usual way of creating an adapter is pulling out a ruler, caliper, measuring everything, making a 3D model, and sending it off to a 3D printer. Instead of doing things the usual way, [Stefan] is using photogrammetric 3D reconstruction to build a camera adapter that fits perfectly in his plane and holds a camera securely.

Photogrammetry requires taking a few dozen pictures with a camera, using software to turn these 2D images into a 3D model, and building the new part from that model. The software [Stefan] is using is Pix4D, a piece of software that is coincidentally used to create large-scale 3D models from drone footage.

With the 2D images turned into a 3D model, [Stefan] imported the .obj file into MeshLab where the model could be cropped, smoothed, and the file size reduced. From there, creating the adapter was as simple as a little bit of OpenSCAD and sending the adapter model off to a 3D printer.

Just last week we saw photogrammetry used in another 3D object scanner. The results from both of these projects show real promise for modeling, especially with objects that are difficult to measure by hand.

Hacklet 88 – Projector Projects

December 11, 2015 by Adam Fabio 5 Comments

Everyone loves a big screen TV. Back in the old days, anything over 27 ” was considered big. These days if you’re not sporting at least 50″, you’ll end up with display envy. One thing hasn’t changed though, those who want to go really, really big get into projectors. Hacking and projectors seem to go hand in hand. Anyone else remember those old DIY projection setups where the user would put their TV in a box upside down? This week’s Hacklet is all about projector hacks!

We start with [Chaz] with Projector Hush Box . [Chaz] had a good projector, but still found himself with a problem. Projectors generate a lot of heat, which is dissipated via a fan. For whatever reason, projector companies seem to pick the loudest fans available. [Chaz’s] solution is to put the projector inside a box. Done right, this makes for a quiet projector. Done wrong, it makes an oven. [Chaz] projector hasn’t caught fire yet, so we think he did it right. Two quiet and efficient PC fans direct air through the box, and around baffles which keep the noise down. An anti-reflective coated glass window lets the light out but keeps the noise in. Sound deadening foam helps cut the sound down even further.

Next up is [ric866] with 100w LED projector conversion. The killer with projectors these days are the bulbs. In some cases it’s more cost-effective to buy a new projector than to replace the bulb in an aging one. That’s how [ric866] ended up with a pair of old NEC projectors – one with a working bulb, and one without. Bulbs for this model aren’t cheap at £100. [ric866] found a cheap replacement in a 100 Watt LED. The LED in question only cost £8.99 from everyone’s favorite auction site. LEDs may be efficient, but anyone who’s played with powerful LEDs can tell you they still get hot. [ric866] had to cut up the projector’s case a bit to fit in a heat sink and fan. He also had to spend some time bypassing the various case interlock switches. The final products color calibration looks to be a bit off, but not too shabby for a quick mod!

[Tom_VdE] is serious about recycling. He isn’t one to let an old laptop go to waste when it can be turned into a projector! Remember the “TV in a box” kit we mentioned up in the title? This is the modern version of that same idea. [Tom] tore down the laptop’s LCD and placed it in a CRT monitor case with the appropriate lenses. A setup like this needs length, and focus adjustments. [Tom] managed all that by building a collapsible baffle out of plywood. A build like this needs a lot of light, so [Tom] is using a 100 Watt LED (or two). A water cooling system will keep the LED’s from melting down. [Tom] is still in the prototype phase, but we can’t wait to see his first movie night with this upcycled laptop.

Finally, we have [Alex] who built Automatic projector calibration, project #161 on Hackaday.io. [Alex] took his inspiration from [Johnny Chung Lee] to build a system which can map a projector to any angle, size, or position. The secret is phototransistors embedded in the corners of a rectangular piece of foamboard. An Arduino reads the phototransistors while the projector runs a calibration routine. [Alex] switched over to a scanning line from [Johnny’s] original binary pattern. The scan isn’t quite as fast as the binary, but it sure looks cool. Once the positions of the sensors are known, it’s just a matter of mapping the entire screen to a smaller piece of real estate. Toss in a few neat transitions, and you’ve got an awesome demo.

If you want to see more projector projects, check out our new projector project list! If I missed your project, don’t be shy, just drop me a message on Hackaday.io. That’s it for this week’s Hacklet. As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!