3D Printed Variable Area Jet Nozzle

If you’ve ever seen the back end of a military jet, you’ve likely seen variable area nozzles. They’re used to adjust the exhaust flow out of the rear of a jet engine during supersonic flight and while the afterburner is engaged. Commercial aircraft, with the exception of the Concorde, don’t need such fancy hardware since a static exhaust nozzle works well enough for the types of flying they’ll be doing. For much the same reasons, RC aircraft don’t need variable area nozzles either, but it doesn’t keep builders from wanting them.

Which brings us to this utterly gorgeous design by [Marco Colucci]. Made up of 23 individual PETG parts, this variable area nozzle is able to reduce its diameter by 50% with just a twist of the rotating collar. When paired with a hobby servo, this mechanism will allow the operator to adjust the nozzle aperture with an extra channel on their RC transmitter. The nozzle hasn’t flown yet, but a test run is being planned with a 40mm Electric Ducted Fan (EDF) motor. But thanks to the parametric design, it shouldn’t be a problem to scale it up to larger motors.

But the big question: does it have an effect on the EDF’s performance? The answer is, of course, no. This doesn’t actually do anything. An EDF motor has no need for this sort of nozzle, and even if you tried to fit this on a scale jet engine, it would melt in seconds from the exhaust temperature. This is purely a decorative item, to give the plane a more accurate scale look. To that end, it looks fantastic and would definitely be impressive on the back of a large scale RC military fighter.

If anything, [Marco] says they expect performance to be worse with the nozzle fitted. Not only is it adding dead weight to the plane, but restricting the air coming out of the back of the fan isn’t going to do anything but reduce thrust. But on the bright side: if it’s flying slower, it will be easier to see how awesome your adjustable nozzles look.

This isn’t the first time somebody’s tried to make an electric RC plane look like it’s packing a proper turbine, but it certainly might be one of the slickest. Only way to top this is to build an actual jet engine for the thing.

Posted in 3d Printer hacks, EDF, jet engine, Nozzle, parametric design, scale model | Leave a comment

Charging USB-C Devices Off Of LiPo Battery Packs

When it was introduced in the late 90s, USB was the greatest achievement in all of computing. Gone were the PS/2 connectors for keyboards and mice, ADB ports, parallel ports, game ports, and serial ports. This was a Tower of Babel that would unite all ports under one standard universal bus.

Then more ports were introduced; micro, mini, that weird one that was a mini USB with more connectors off to the side. Then we started using phone chargers as power supplies. The Tower of Babel had crumbled. Now, though, there is a future. USB-C is everything stuffed into one port, and it can supply 100 Watts of power.

Delivering power over a USB-C connector is an interesting engineering challenge, and for his Hackaday Prize entry, [Chris Hamilton] is taking up the task. He’s building a USB-C battery charger, allowing him to charge standard R/C battery packs over USB.

There are two major components of the charger. The first, a Cypress CCG2 USB Power Delivery negotiator, handles all the logic of sending a command to the USB power supply and telling it to open up the pipes. It’s an off-the-shelf part and the implementation is well documented in app notes. The second major component is the battery management circuit built on a TI BQ40z60RHB. This includes the charger control logic and the ability to balance up to four cells. Battery connectors are XT-30, so all your drone battery packs can now be charged by a MacBook.

Posted in 2018 Hackaday Prize, lipo, The Hackaday Prize, USB C, XT-30 | Leave a comment

Blinging Buttons for Pick and Place

With 3D-printing, cheap CNC machines, and the huge variety of hardware available these days, really slick-looking control panels are getting to be commonplace. We’re especially fond of those nice indicators with the chrome bezels, and the matching pushbuttons with LED backlighting; those can really make a statement on a panel.

Sadly for [Proto G], though, the LEDs in his indicator of choice were just boring old one-color units, so he swapped them out and made these addressable RGB indicators. The stock lamps are not cheap units, but they do have a certain look, and they’re big enough to allow room for a little modification. The original guts were removed with a Dremel to make way for a Neopixel board. [Proto G] wanted to bring the board’s pads out to screw terminals, so he had to adapt the 3.0-mm pitch blocks he had on hand to the 2.54-mm pitch on Neopixel board, but that actually came out neater than you’d think. With a little hot glue to stick it all back together, he now has fully-addressable indicators that can be daisy-chained together and only take up a single GPIO pin.

These indicators and the nice looking panel they’re on is part of a delta pick-and-place robot build [Proto G] has been working for a while. He’s had some interesting side projects too, like the clickiest digital clock in the world and easing ESP32 setup for end-users. While we like all his stuff, we can’t wait to write up the finished delta.

Posted in control panel, indicator, led, led hacks, neopixel, pilot, rgb, switch | Leave a comment

Casting a 3D Printed Extruder Body in Aluminum

Creating 3D prints is great, but sometimes you need something more durable. [Myfordboy] printed a new 3D printer extruder in PLA and then used the lost PLA method to cast it in aluminum. You can see the results in the video below.

The same process has been used for many years with wax instead of PLA. The idea is to produce a model of what you want to make and surround it with a material called investment. Once the investment sets, heat melts the PLA (or wax) leaving a mold made of the investment material. Once you have the mold, you can place it in a frame and surround it with greensand. Another frame gets a half pipe placed and packed with greensand. The depression made by this pipe will provide a path for the metal to flow into the original mold. Another pipe will cut a feeder into the greensand over this pipe.

Sounds simple enough, but there are a few good tips in the video. For example, the way he used a food storage container to hold the investment and a sander to vibrate air bubbles out of it. Watching him place the feeder and well was very instructive, too.

If you don’t have a forge, but you have a microwave, you might want to read how to use the microwave. We’ve also seen other detailed lost PLA processes, you might want to check out.

Posted in 3d Printer hacks, aluminum casting, casting, lost PLA, lost pla casting | Leave a comment

A Tale Of More Than One Amiga 1500

If you were an Amiga enthusiast back in the day, the chances are you had an Amiga 500, and lusted after a 2000 or maybe later a 3000. Later still perhaps you had a 600 or a 1200, and your object of desire became the 4000. The amusingly inept Commodore marketing department repackaged what was essentially the same 68000-based Amiga at the bottom end of the range through the platform’s entire lifetime under their ownership, with a few minor hardware upgrades in the form of chipset revisions that added a relatively small number of features.

We’ve probably listed above all the various Amigas you’ll be familiar with, with a few exceptions you either didn’t have or only saw in magazines. The original A1000, the chipset-upgraded A500+, the CDTV multimedia  platform, or the CD32 games console as examples. But there’s one we haven’t listed which you may never have seen unless you hail from the United Kingdom, and it’s an Amiga behind which lies a fascinating tale that has been unearthed by [RetroManCave].

In the late 1980s, Commodore sold the A500 all-in-one cased Amiga to consumers with marketing based heavily upon gaming, and the A2000 desktop Amiga to businesses with the promise of productivity software. Both machines had a 16-bit Motorola 68000 running at the same speed, with the A2000 having a lot of extra memory and a hard drive lurking within that case. The price difference between the two was inordinately high, creating a niche for an enterprising British company called Checkmate Computers to fill with their provocatively named A1500, a clever case for an A500 mainboard that gave it an expansion slot and space for that hard drive and memory.

This machine’s existence angered Commodore, to the extent that they vowed to eradicate the upstart by releasing their own UK-only A1500. The result, a comically badly concealed rebadge of an A2000 with two floppies and no hard drive, is something we remember seeing at the time, and dare we admit it, even lusting after. But the full story in the video below is well worth a watch for an engrossing insight into a little-known saga in one corner of the computing world during the 16-bt era. Towards the end it becomes a plug for the Checkmate Computers co-founder’s current Kickstarter project, but if that holds no interest for you then you are at least forewarned.

Of course, if you have either A1500 today, you might want an up-to-date graphics card for it.

Via Hacker News.

Posted in amiga, amiga 1500, classic hacks, retro computer, retro computing, retrocomputing | Leave a comment

Custom Circuit Makes for Better Battery Level Display

Isn’t it always the way? There’s a circuit right out of the textbooks, or even a chip designed to do exactly what you want — almost exactly. It’s 80% perfect for your application, and rather than accept that 20%, you decide to start from scratch and design your own solution.

That’s the position [Great Scott!] found himself in with this custom LED battery level indicator. As the video below unfolds we learn that he didn’t start exactly from scratch, though. His first pass was the entirely sensible use of the LM3914 10-LED bar graph driver chip, a device that’s been running VU meters and the like for the better part of four decades. With an internal ladder of comparators and 1-kilohm resistors, the chip lights up the 10 LEDs according to an input voltage relative to an upper and lower limit set by external resistors. Unfortunately, the fixed internal resistors make that a linear scale, which does not match the discharge curve of the battery pack he’s monitoring. So, taking design elements from the LM3914 datasheet, [Great Scott!] rolled his own six-LED display from LM324 quad-op amps. Rather than a fixed resistance for each stage, trimmers let him tweak the curve to match the battery, and now he knows the remaining battery life with greater confidence.

Perhaps the 18650 battery pack [Great Scott!] is building is for the e-bike he has been working on lately. If it is, we’re glad to see that he spot-welded the terminals, unlike a recent e-bike battery pack build that may have some problems down the road.

Posted in bargraph, battery, battery gauge, battery meter, comparator, led hacks, lm324, lm3914, misc hacks, voltage | Leave a comment

Mademoiselle Pinball Table Gets Rock ‘n Roll Makeover

Once upon a time, there was a music venue/artist collective/effects pedal company that helped redefine industry in Williamsburg, Brooklyn. That place was called Death By Audio. In 2014, it suffered a death by gentrification when Vice Media bought the building that DBA had worked so hard to transform. From the ashes rose the Death By Audio Arcade, which showcases DIY pinball cabinets made by indie artists.

Their most recent creation is called A Place To Bury Strangers (APTBS). It’s built on a 1959 Gottlieb Mademoiselle table and themed around a local noise/shoegaze band of the same name that was deeply connected to Death By Audio. According to [Mark Kleeb], this table is an homage to APTBS’s whiz-bang pinball-like performance style of total sensory overload. Hardly a sense is spared when playing this table, which features strobe lights, black lights, video and audio clips of APTBS, and a fog machine. Yeah.

[Mark] picked up this project from a friend, who had already cut some wires and started hacking on it. Nearly every bit of the table’s guts had to be upgraded with OEM parts or else replaced entirely. Now there’s a Teensy running the bumpers, and another Teensy on the switches. An Arduino drives the NeoPixel strips that light up the playfield, and a second Uno displays the score on those sweet VFD tubes. All four micros are tied together with Python and a Raspi 3.

If you’re anywhere near NYC, you can play the glow-in-the-dark ball yourself on July 15th at Le Poisson Rouge. If not, don’t flip—just nudge that break to see her in action. Did we mention there’s a strobe light? Consider yourself warned.

Want to get into DIY pinball on a smaller scale? Build yourself a sandbox and start playing.

Posted in arduino, Arduino Hacks, darlington array, Gottlieb, Microcontrollers, Neopixels, pinball, repair hacks, Teensy | Leave a comment

This Is Your Last Chance To Design The Greatest In Power Harvesting

This is your last weekend to get your project together for the Power Harvesting Challenge in this year’s Hackaday Prize. We’re looking for projects that harvest energy from the ether, and power electronics from solar, thermal, wind, light, or random electromagnetic fluctuations. Is it going to save the world? Maybe, but it’s a great excuse to build some really cool electronics. If you have an idea in mind, this is your last weekend to enter it in the Power Harvesting Challenge.

The Hackaday community has thrown itself full-force into the Hackaday Prize, and there are hundreds of projects entered in this year’s Prize. Next week, we’ll choose the top twenty projects entered during the Power Harvesting Challenge to advance to the finals. Each of those twenty projects will be awarded $1,000 and be in the running to win the Grand Prize of $50,000 and four other top cash prizes.

This is your last chance to get in on the Power Harvesting Challenge in this year’s Hackaday Prize. For this challenge, we’re looking for projects that harvest energy from any source. It could be a module, or as a distinct design easily incorporated into other builds. Don’t wait — start your entry now.

The Power Harvesting Challenge ends a 07:00 AM PDT on July 16th. Afterwards, we’ll be continuing on into Human-Computer Interface and Musical Instrument Challenges. This is your shot to get your project in the finals in the Hackaday Prize. Don’t miss out!

Posted in 2018 Hackaday Prize, Hackaday Columns, Power Harvesting Challenge, The Hackaday Prize | Leave a comment

ERRF 18: New Products Make their Debut

While ostensibly the purpose of the recent East Coast RepRap Festival (ERRF) was to celebrate the 3D printing community and culture, it should come as no surprise that more than a few companies decided to use the event as an opportunity to publicly launch new products. Who can blame them? It’s not as if every day you have a captive audience of 3D printing aficionados; you might as well make the best of it.

Many creations were being shown off for the first time at ERRF, and we surely didn’t get a chance to see them all. There was simply too much going on at any given time to be sure no printed stone was left unturned. But the following printers, filaments, and accessories caught our attention long enough to warrant sharing with the good readers of Hackaday.

Keep in mind that much of this information is tentative at best, and things could easily change between now and when the products actually go on sale. These events serve as much as a sounding board for new products as they do a venue for advertising and selling them, so feedback received from show attendees may very well alter some of these products from what we saw at ERRF.

Venturi 3D

Out of all the 3D printers on display at ERRF, the Venturi 3D still managed to stand out. While so many other companies are putting out vaguely Prusa i3 inspired designs, the Venturi looks more like a modern “smart” refrigerator. Whether or not that is an improvement is up to the individual, but it certainly looks very professional.

A fully enclosed machine is still somewhat rare in the desktop 3D printer market, but creator Chris Lane has gone one better and brought the filament inside the enclosure as well. Not just one roll either, but four; as the Venturi just so happens to be multi color/material capable. In theory, bringing the filament inside the enclosure solves the issue of how you keep in-use filament dry. But the lack of any obvious seals around the multiple doors on the Venturi does make us skeptical that the interior humidity of the machine would ever be much different from ambient.

The quad Bowden extruders feed a E3D V6 hotend via low-friction Capricorn XS PTFE tubing, and the CoreXY motion is provided by a DuetWifi controller. An Android tablet running custom software provides the front panel interface, and comes pre-loaded with 1,000+ 3D models which the user can select from multiple categories. These models have been sliced specifically for the Venturi, and are there to give the user a baseline library of known good prints.

An earlier prototype of the Venturi 3D printer was on display at MRRF, but according to Chris, the build demoed at ERRF was the final version which is slated to go on sale later this summer for $1,299.

Printrbot Easy

In a somewhat surprising move, Printrbot CEO Brook Drumm used ERRF as an opportunity to present a potential new product which he’s calling the “Easy”. Realizing that a race to the bottom against overseas manufacturers is simply not possible for a small American company, the team at Printrbot are instead looking at the possibility of modifying and branding an imported printer.

Printrbot has long been a champion of both open source and local manufacturing, so seeing what’s clearly a FlashForge Finder with Printrbot logos on it left some attendees scratching their heads. But Brook assured anyone who asked that the traditional Printrbot way of doing things isn’t going away. Selling a branded printer simply allows them to maintain a presence in the entry-level printer market while focusing their R&D on bigger and better things. Indeed, right next to the Printrbot Easy was the latest version of the Printrbelt, a truly unique printer that had no parallel at ERRF.

Brook says he hasn’t fully committed to releasing the Printrbot Easy, and will be using feedback from ERRF to help make the final decision. If the product does go live, expect a sub-$400 price tag and the same support and warranty Printrbot offers on their in-house machines.

Budmen Buildini

Budmen Industries is best known for their large-scale functional prints, from chairs to lampshades. These have been printed in-house with a large printer of their own design, and the lessons they’ve learned from that machine have inspired them to release a commercial printer for other creators and artists who want to go big.

With a 500x300x490mm build area the Buildini offers plenty of room to grow, and the Titan Aero combination extruder/hotend will certainly be able to lay down the filament. Some might be surprised by the lack of a heated bed, but without an enclosure it’s unlikely you’d be able to keep large ABS prints from warping anyway. Low-warp materials like PLA and PETG will be order of the day.

The design of the Buildini looks both robust and exceptionally simple. The design does away with separate linear rails or smooth rods, and instead moves the entire extruded aluminum frame. It’s an interesting approach, and offers a fantastically low part-count considering how large the printer is.

The Buildini will be manufactured at Budmen Industries headquarters in Philadelphia, and will start shipping in September for $2,300.

RepKord RepBox

Aiming to provide a little higher class air-tight storage for your rolls of filament than the plastic tote most of us are using currently, Repkord has created the RepBox. This wall mounted filament storage system gives you a way to keep filament dry and ready for immediate use. The RepBox is made of steel and MDF, but a clear acrylic version of the box that was on display ended up being such a hit that it’s now available as an option.

Thanks to internal rollers and standard pneumatic fittings, up to eight rolls of filament can be used simultaneously without exposing them to the ambient air. If you’ve got a wall of 3D printers in your shop, or you’re running a multi material/color setup, this would be an excellent way to centralize your filament supply.

The standard kit is available on the RepKord site for $89.99, and the clear version will set you back $139.99.

Tangerine Orange Metallic (TOM)

During his recent tour of the US, Thomas Sandlanderer teamed up with Proto-Pasta to come up with his own automotive-inspired color of HTPLA. A beautiful orange with an infusion of silver glitter, the color was so popular that Proto-Pasta decided to add it to the official lineup and sell it for the first time ever at ERRF. It’s now available on their website at $29.99 for a 500g spool.

An Impressive Start

Considering this was the first time the East Coast RepRap Festival was held, an impressive number of products were unveiled during the two days of the show. These manufacturers had enough faith in the 3D printing community to come out and support an untested venue that they were willing to hinge their launch on it. Judging by the number of attendees, we’d say the gamble paid off and can’t wait to see what next year brings.

Posted in 3d Printer hacks, Buildini, cons, ERRF, ERRF 18, hardware, printrbot, Proto-Pasta, Venturi | Leave a comment

Supersize DIY R/C Servos From Windscreen Wipers

We’re all familiar with the experience of buying hobby servos. The market is awash with cheap clones which have inflated specs and poor performance. Even branded servos often fail to deliver, and sometimes you just can’t get the required torque or speed from the small form factor of the typical hobby servo.

Enter [James Bruton] and his DIY RC servo from a windscreen wiper motor. Windscreen wiper motors are cheap as chips, and a classic salvage. The motor shaft is connected to a potentiometer via a pulley and some string, providing the necessary closed-loop feedback. Instead of using the traditional analog circuitry found inside a servo, an Arduino provides the brains. This means PID control can be implemented on the ‘duino, and tuned to get the best response from different load characteristics. There’s also the choice of different interfacing options: though [James]’ Arduino code accepts PWM signals for a drop-in R/C servo replacement, the addition of a microcontroller means many other input signal types and protocols are available. In fact, we recently wrote about serial bus servos and their numerous advantages.

We particularly love this because of the price barrier of industrial servomotors; sure, this kind of solution doesn’t have the precision or torque that off-the-shelf products provide, but would be sufficient for many hacks. Incidentally, this is what inspired one of our favourite open source projects: ODrive, which focuses on harnessing the power of cheap brushless motors for industrial use.

Posted in 3d print, 3d Printer hacks, arduino, Arduino Hacks, conversion, dc, james bruton, Microcontrollers, pid, servo | Leave a comment