E3D Introduces Tool Changing 3D Printer

March 24, 2018 by 40 Comments

E3D has introduced their latest answer to multimaterial printing at the Midwest RepRap Festival this weekend. Their research project into a 3D printer with the ability to change toolheads is the latest advancement in multimaterial printing. It’s a work of engineering brilliance, and they’ve already written up their teardown on how this all came to be.

While milling machines and other fancy industrial CNC have had tool changing for decades, and the subject has been pursued by the RepRap community for a few years now, it really hasn’t caught on. The question then is, what is tool changing on a 3D printer good for? The answer is multimaterial printing, and doing it in a way that doesn’t have the downsides of current methods of printing with multiple materials.

There are three current methods of printing in multiple materials. The first is putting two nozzles on the same extruder, but this has the downside of one nozzle interfering with the other. The second is pushing two different kinds of plastic through the same nozzle, such as in the E3D Cyclops, or Prusa’s multimaterial upgrade. This has the downside of cross-contamination, and you can’t print in materials that require different temperature profiles. The third method is simply using multiple carriages on the same machine, such as the lovely stuff from Autodesk or Project Escher. This last method is horrifically complex.

The answer the problem of multimaterial printing is hot-swapping toolheads, but to do this you need precision and repeatability. The folks at E3D have been working on this for years, and I remember seeing some experiments with electro-permanent magnets a few MRRFs ago, but now they finally have a solution. The answer is simply a cam that’s turned by a cheap hobby servo. This is kinematic coupling that allows the carriage to clamp onto a toolhead with 5 μm precision.

Right now, E3D’s experiments in toolchanging 3D printers have culminated in a single 3D printer featuring their toolchange carriage, four toolheads, some amazing linear rails, and a CoreXY configuration. The prints that are coming off of this printer are spectacular. There are four-color Benchies, and the drivetrain of a remote-controlled car with gears printed in Taulman plastic and a driveshaft printed in ABS. The car was a single print made with multiple hotends, demonstrating most of the problems of multimaterial printing disappear with the E3D swapping toolhead printer.

The cam-lock mechanism on the carriage
Cam-lock mechanism
toolheads
two-color multimaterial print
four-color benchy
Cute Kracken

If you’re interested in purchasing one of these printers, E3D currently has a survey for potential buyers and a deposit queue for any future purchases.

US Military Developing Laser Plasma Speakers

March 24, 2018 by 27 Comments

It probably won’t surprise you to know that the US military is very interested in using lasers as weapons. Directed energy weapons such as lasers have many advantages over more traditional kinetic weaponry, not least of which the fact that you don’t need to cart around ammunition for them. But somewhat surprisingly, some of the most promising laser developments have been in the field of non-lethal weaponry. While the mental image of a laser is usually a destructive one, recent demonstrations by the Joint Non-Lethal Weapons Program show lasers can do more than blow holes your target.

As reported by [Patrick Tucker] of Defense One, a radical new laser-powered sonic weapon was shown off at the “Directed Energy to DC Exhibition”. The system uses two lasers: one to generate a ball of plasma when it hits the target, and another to modulate the plasma ball in open air. The result is a variation of the classic plasma speaker demonstration, where plasma is used as a a driver for a massless speaker.

Currently the system is capable of generating a deafening crack at the target area, with a measured intensity as high as 140 dB. That’s about as loud as fireworks or a shotgun going off at close distance, and in theory is enough to drive off whoever is unlucky enough to be targeted with the beam.

In time, the researchers hope to refine their secondary modulation laser to the point that they can play audio over the plasma. This would allow the beam to be used as a directed loud speaker of sorts, which could prove useful for defensive applications. Only the target would be able to hear the audio, which could be a recording telling them they were entering a secured area. A disembodied voice telling you to turn around sounds like a extremely effective non-violent deterrent to us. The voices in our head don’t have to tell us twice.

We recently looked at the possibility of targeted sonic weapons being used in Cuba, and of course, we’ve covered many plasma speakers on Hackaday over the years. Plasma speakers have always been more or less nothing more than a fun high voltage demonstration, so to see them potentially weaponized is a crossover episode we weren’t expecting.

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Lasers, Mirrors, And Sensors Combine In An Optical Bench Game

March 24, 2018 by 11 Comments

Who would have thought you could make a game out of an optical bench? [Chris Mitchell] did, and while we were skeptical at first, his laser Light Bender game has some potential. Just watch your eyes.

The premise is simple: direct the beam of a colored laser to the correct target before time runs out. [Chris] used laser-cut acrylic for his playfield, which has nine square cutouts arranged in a grid. Red, green, and blue laser pointers line the bottom of the grid, with photosensors and RGB LEDs lining the grid on the other three sides. Play starts with a random LED lighting up in one of the three colors, acting as a target. The corresponding color laser comes on, and the player has to insert mirrors or pass-through blocks in the grid to create a path to the target. The faster you hit the CdS cell, the higher your score. It’s simple, but it looks really engaging. We can imagine all sorts of upgrades, like lighting up two different targets at once, or adding a beamsplitter block to hit two targets with the same color. Filters and polarizers could add to the optical fun too.

We like builds that are just for fun, especially when they’re well-crafted and have a slight air of danger. The balloon-busting killbots project we featured recently comes to mind.

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Cordless Tool Battery Pack Turned Into Portable Bench Supply

March 24, 2018 by 18 Comments

Say what you want about the current crop of mass-marketed consumer-grade cordless tools, but they’ve got one thing going for them — they’re cheap. Cheap enough, in fact, that they offer a lot of hacking opportunities, like this portable bench power supply that rides atop a Ryobi battery.

Like many of the more common bench supply builds we’ve seen,  [Pat K]’s more portable project relies on the ubiquitous DPS5005 power supply module, obtained from the usual sources. [Pat K] doesn’t get into specifics on performance, but supplied with 18 volts from a Ryobi One+ battery, the DC-DC programmable module should be able to do up to about 16 volts. Mating the battery to the supply is easy with the 3D-printed case, which has a socket for the battery that mimics the sockets on tools from the Ryobi line. It’s simple and effective, as well as neatly executed. The files for the case are on Thingiverse; sadly, only an STL file is included, so if you want to support another brand’s batteries, you’ll have to roll your own.

Check out some of the other power supplies we’ve featured that use the DPS5005 and its cousins, like this nice bench unit. We’ve also covered some of the more hackable aspects of this module, such as an open-source firmware replacement.

Business On The Outside, Electronics Workstation On The Inside

March 23, 2018 by 15 Comments

As an electrical engineering student, [Brandon Rice] had the full suite of electronics tools you’d expect. Cramming them all into a dorm room was doable — but cramped — a labour to square everything away from his desk’s top when he had to work on something else. To make it easier on himself, he built himself a portable electronics workstation inside the dimensions of a briefcase.

Built from scratch, the workstation includes a list of features that should have you salivating by the end. Instead of messing with a bunch of cables, on-board power is supplied by a dismantled 24V, 6A power brick, using a buck converter and ATmega to regulate and display the voltage, with power running directly to  12V and 5V lines of a breadboard in the middle of the workstation. A wealth of components are stored in two dozen 3d printed 1″ capsules setting them in loops pinned to the lid.

If all this was not already enough, there’s more!

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Ground-Effect Lighting For Your Bed.

March 23, 2018 by 24 Comments

If you’ve ever disturbed your partner by getting up during the night and flicking on the bathroom light — or tripping over something and startling them awake completely in the ensuing catastrophe — [Kristjan Berce]’s idea to install motion-activated ground-effect lighting on his girlfriend’s bed might hold your attention.

[Berce] is using an Arduino Nano for the project’s brain, a PIR sensor from Adafruit, and an L7805 voltage regulator to handle load spikes.  He doesn’t specify the type of LED strip he’s using, but Neopixels might be a safe bet here. Soldering issues over with, he mounted his protoboard in a 3D printed project box. Instead of reinventing the LED, [Berce] copied the code from Adafruit’s PIR tutorial before sticking the project to the side of the bed with adhesive strips so the on/off switch within handy reach to flick before meeting Mr. Sandman. Check out the build video after the break!

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DIY Perpetual Flip Calendar

March 23, 2018 by 12 Comments

Flip calendars are a neat little piece of history. Sold as tourist trinkets, they sit on your desk and show the current day of the month and, depending on the particular calendar, month and year. Each day, you rotate it and it shows you the current date. At the end of February, you rotate it a bunch of times to get from February 28th (or 29th) to March 1st. [measuredworkshop] always had fun flipping the dates on his parents’ flip calendar, so decided to build his own wooden one.

The calendars consist of a series of tiles with the dates on them inside an enclosure. Rotating the enclosure allows a new tile to slide down in front of the old one. Once you know how many tiles you are going to use, you put a different date on the back side of each tile. In [measuredworkshop]’s case, there were 15 tiles to hold 30 dates (he created one with 30/31 on it for the end of the month) so the 1 has a 16 on the back, the 2 a 17, and so on. Tiles of different colored wood were cut and sanded and then the numbers drawn on by hand.

The enclosure was cut using a Morso Guillotine, a machine which uses sharp blades to do precise mitre cuts in wood. One side of the enclosure was covered by wood, the other by clear acrylic, so that you can see how the mechanism works as it is rotated. Finally, a stand was cut from wood as well and the final product assembled.

As you can see in the video below this is a great showpiece, and because of the design gives a view into how flip-calendars work. At the end of his write-up, [measuredworkshop] shares a link he found to a 3d printed flip-calendar on Thingiverse. Check out some of the more techie calendars posted at Hackaday, like this e-ink calendar, or this Raspberry Pi wall calendar.

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