Well, here it is: a shoe-in for the new world’s largest NERF gun. (Video, embedded below.) The Guinness people haven’t shown up yet to award [Michael Pick], but at 12.5 feet, this baby is over twice as long as the current record holder, which belongs to former NASA mechanical engineer Mark Rober and his now-puny six-foot six-shooter.

We have to wonder if it is technically bigger than the six-shooter, because they seem to be roughly the same scale, except that [Michael] chose a much bigger model to start from. The main body is made from wood, and there are a ton of 3D-printed details that make it look fantastically accurate. The whole thing weighs over 200 pounds and takes at least two people to move it around. We especially love the DIY darts that [Michael] came up with, which are made from a PVC tube inside a section of pool noodle, topped off with a 3D printed piece for that distinctive orange cap.

Propelling those darts at around 50 MPH is a 3,000 PSI air tank connected to an Arduino Pro Mini that controls the trigger and the air valves. While [Michael] hasn’t run the thing quite that high, it does plenty of damage in the neighborhood of 40-80 PSI. As you’ll see in the video after the break, this is quite the ranged weapon. Watch it blow a hole clean through a sheet of drywall and much more.

Want to build something with a bit more stealth? Make it death from above with a NERF quadcopter.

Tic-tac-toe (or “Noughts and Crosses”) is a game simple enough to implement in any computer system: indeed it’s often used in beginner’s programming courses. A more challenging project, and arguably more interesting and useful, is to make some kind of hardware that can play it in real life. [mircemk] built a simple yet elegant machine that can play tic-tac-toe against a human player in a way that looks quite similar to the way humans play against one another: by drawing.

The robot’s design and programming were developed at PlayRobotics, who named the project TICO. The mechanical parts are available as STL files, to be printed by any 3D printer, and a comprehensive manual explains how to assemble and program the whole thing. Since it’s all open source, anyone can build it from scratch and modify it to their liking. The pictures show the original design by PlayRobotics, while the video (embedded after the break) shows [mircemk]’s version, which includes a wooden frame that gives it a bit more presence.

The electronic components are an Arduino with an OLED screen and a buzzer, plus three servos to operate the mechanical parts. Lacking a 3D printer, [mircemk] cut the plastic parts from a 3 mm sheet of PVC, which seems to have worked surprisingly well. The game board consists of a small whiteboard on which the robot and the human can draw their O’s and X’s.

The mechanical structure of the robot looks a bit like a tiny human using both arms to draw with an enormous marker. When starting a game, the robot clears the whiteboard using a little eraser, then draws the standard 3×3 grid and makes its first move. The human then draws their move and uses a remote control to tell the robot what they did (no machine vision here), after which the game continues until there is either a winner or the game results in a draw.

Although it looks like the program’s playing strategy may need some fine-tuning, the mechanical part is well-designed and the arms’ motions are quick and steady. We love the celebratory “cheering” at the end of a game, which TICO does whether it won or not.

The robot’s basic design is inspired by the Plotclock, which uses a similar setup to draw the time. We’ve seen other tic-tac-toe ‘bots before, as well as some clever electronic implementations of the game.

We’ve seen a great many Arduino synthesizer projects over the years. We love to see a single Arduino bleeping out some monophonic notes. From there, many hackers catch the bug and the sky is truly the limit. [Kevin] is one such hacker who now has an Arduino orchestra capable of playing all seven movements of Gustav Holst’s Planets Suite.

The performers are not human beings with expensive instruments, but simple microcontrollers running code hewn by [Kevin’s] own fingertips. The full orchestra consists of 11 Arduino Nanos, 6 Arduino Unos, 1 Arduino Pro Mini, 1 Adafruit Feather 32u4, and finally, a Raspberry Pi.

Different synths handle different parts of the performance. There are General MIDI synths on harp and bass, an FM synth handling wind and horn sections, and a bunch of relays and servos serving as the percussive section. The whole orchestra comes together to do a remarkable, yet lo-fi, rendition of the whole orchestral work.

While it’s unlikely to win any classical music awards, it’s a charming recreation of a classical piece and it’s all the more interesting coming from so many disparate parts working together. It’s an entirely different experience than simply listening to a MIDI track playing on a set of headphones.

We’d love to see some kind of hacker convention run a contest for the best hardware orchestra. It could become a kind of demoscene contest all its own. In the meantime, scope one of [Kevin’s] earlier projects on the way to this one – 12 Arduinos singing Star Wars tracks all together. Video after the break.

If you are lucky, you’ve never experienced the heartbreak of watching a loved one lose their ability to do simple tasks. However, as hackers, we have the ability to customize solutions to make everyday tasks more accessible. That’s what [omerrv] did by creating a very specific function remote control. The idea is to provide an easy-to-use interface for the most common remote functions.

This is one of those projects where the technology puzzle is now pretty easy to solve: IR remotes are well-understood and there are plenty of libraries for recording and playing back signals. The real work is to understand the user’s challenges and come up with a workable compromise between something useful and something too complex for the user to deal with.

Fortunately, with all the prototyping tools readily available now, it is easy to experiment with different setups to see what would work best. Larger keys? Color coding? A different arrangement of buttons? All of those things are easy to experiment with and, of course, what works for one person might not work for another. Even given time, it is possible that different configurations will work better or worse for the same person.

It isn’t likely that you’d duplicate [omerrv’s] remote directly. It may not work for your purpose. But it is a good inspiration on how we can use our ability to create customized hardware to improve the quality of life for those who need help.

We’ve seen similar projects — each one is a bit different. We wonder if old-fashioned remotes with their natural limitations would be a bit easier for people to handle?

When you have a small stock of vacuum fluorescent displays (VFDs) straight out of the 1976 Radio Shack catalog, you might sit around wondering what to do with them. When [stepawayfromthegirls] found out that his stash of seven DT-1704A tubes may be the last in existence, there was no question. They must be displayed! [stepawayfromthegirls]’ mode of display is this captivating clock build. Four VFDs with their aqua colored elements are set against a black background in a bespoke wooden case. Looking under the hood, the beauty only increases.

Keeping the build organized was not an easy task because the tubes are designed in such a way that each segment must be individually controlled. The needed I/O duties are provided by an Arduino Mega 2560 Pro (Embed). 28 2n3904’s each with their two resistors serve as drivers for each VFD segment.

The output of a  24 V AC transformer left over from the 1980s is rectified to 34 V of DC power which is then regulated to 27 V to power the tubes. Switching power supplies provide 6 V to the Arduino and 1.3 V to the filaments. If you look closely, you’ll also see a GPS module so that the clock doesn’t need to be set. To future-proof the clock against daylight savings time adjustments, a potentiometer on the back of the case allows the user to set custom hour offsets without editing any code.

We think the end result is a remarkably clean, simple, and elegant clock that he will be proud of for many years to come!

If VFD clock builds are your thing, then you’ll enjoy this Network Attached VFD Clock and a Mini VFD Clock with floating display.  And while not VFD based, we’d be silly to leave out the Boat Anchor Nixie Clock with enough knobs, switches, and buttons to delight even the fussiest of hacker.

Do you kind of want a macropad, but aren’t sure that you would use it? Hackaday alum [Jeremy Cook] is now making and selling the JC Pro Macro on Tindie, which is exactly what it sounds like — a Pro Micro-based macro keypad with an OLED screen and a rotary encoder. In the video below, [Jeremy] shows how he made it into a music maker by adding a speaker and a small solenoid that does percussion, all while retaining the original macro pad functionality.

[Jeremy]’s original idea for a drum was to have a servo seesawing a chopstick back and forth on the table as one might nervously twiddle a pencil. That didn’t work out so well, so he switched to the solenoid and printed a thing to hold it upright, and we absolutely love it. The drum is controlled with the rotary encoder: push to turn the beat on or off and crank it to change the BPM.

To make it easier to connect up the solenoid and speaker, [Jeremy] had a little I²C helper board fabricated. There’s one SVG connection and another with power and ground swapped in the event it is needed. If you’re interested in the JC Pro Macro, you can pick it up in various forms over on Tindie. Of course, you might want to wait for version 2, which is coming to Kickstarter in October.

There are many ways to make a macro keyboard. Here’s one that also takes gesture input.

[Larry Bank]’s Arduino library to print text and graphics on BLE (Bluetooth Low Energy) thermal printers has some excellent features, and makes sending wireless print jobs to a number of common models about as easy as can be. These printers are small, inexpensive, and wireless. That’s a great mix that makes them attractive for projects that would benefit from printing out a hardcopy.

It’s not limited to simple default text, either. Fancier output can be done using Adafruit_GFX library-style fonts and options, which sends the formatted text as graphics. You can read all about what the library can do in this succinct list of concise functions.

But [Larry] hasn’t stopped there. While experimenting with microcontrollers and BLE thermal printers, he also wanted to explore talking to these printers from his Mac using BLE directly. Print2BLE is a MacOS application that allows dragging image files into the application’s window, and if the preview looks good, the print button makes it come out of the printer as a 1-bpp dithered image.

Small thermal printers make for neat projects, like this retrofitted Polaroid camera, and now that these little printers are both wireless and economical, things can only get easier with the help of a library like this. Of course, if that’s all starting to look a little too easy, one can always put the thermal back in thermal printing by using plasma, instead.

How far would you go for your cup of tea? [samsungite]’s missus doesn’t like clutter on her countertops, so away the one-cup kettle would go back into the cupboard for next time while the tea steeped. As long as there’s room for it in there, why not install it there permanently? That’s the idea behind RoboTray, which would only be cooler if it could be plumbed somehow.

RoboTray went through a few iterations, most importantly the switch from 6mm MDF to 4 mm aluminum plate. A transformer acts as a current sensor, and when the kettle is powered on, the tray first advances forward 7 cm using a 12 VDC motor and an Arduino. Then it pivots 90° on a lazy Susan driven by another 12 VDC motor. The kettle is smart enough to turn itself off when finished, and the Arduino senses this and reverses all the steps after a ten-second warning period. Check it out in action after the break.

If [samsungite] has any more Arduinos lying around, he might appreciate this tea inventory tracker.

We aren’t sure if you really need lasers to build [HoPE’s] laser harp. It is little more than some photocells and has an Arduino generate tones based on the signals. Still, you need to excite the photocells somehow, and lasers are cheap enough these days.

Mechanically, the device is a pretty large wooden structure. There are six lasers aligned to six light sensors. Each sensor is read by an analog input pin on an Arduino armed with a music-generation shield. We’ve seen plenty of these in the past, but the simplicity of this one is engaging.

We’ve used the copper tape writing trick ourselves and it is quite effective. The tape is often used for stained glass work and sticks to many surfaces. You can solder to it and solder overlaps where you need connections. The results are often as good as a simple single-sided PCB.

The code attached to the post is fairly straightforward and the MIDI shield does the bulk of the work. It should also make it easy to create some really impressive musical effects with a bit of extra coding.

If you want an artsy self-contained version, check out this previous Hackaday Prize entry. We’ve seen several of these at different levels of complexity.

Raise you’re hand if you’ve ever soldered directly to a battery even though you know better. We’ve all been there. Sometimes we get away with it when we have a small pack and don’t care about longevity. But when [Robert Dunn] needed to build a battery pack out of about 120 Lithium Ion cells, he knew that he had to do it The Right Way and use a battery spot welder. Of course, buying one is too simple for a hacker like [Robert]. And so it was that he decided to Build a Spot Welder from an old Microwave Oven and way too much mahogany, which you can view below the break.

For the unfamiliar, a battery spot welder is the magical device that attaches tabs to rechargeable batteries. You’ll notice that all battery packs with cylindrical cells have a tab with two small dimples. These dimples are where high amperage electricity quickly heats the battery terminal and the tab until they’re red hot, welding them together. The operation is done and over in less than a second, well before any heat damage can be done. The tab can then be soldered to or spot welded to another cell.

One of the most critical parts of spot welding batteries is timing. While [Robert Dunn] admits that a 555 timer or even just a manual switch and relay could have done the job, he opted for an Arduino Uno with a 4 character 7 segment LED display that shows the welding time in milliseconds. A 3d printed trigger and welder handle wrap up the hardware nicely.

The build is topped off by a custom mahogany enclosure that is quite a bit overdone. But if one has the wood, the time, the tools and skills (and a YouTube channel perhaps?) there’s no reason not to put in the extra effort! [Robert]’s resulting build is almost too nice, but it’ll certainly get the job done.

Of course, spot welders are almost standard fare here at Hackaday, and we’ve covered The Good, The Bad, and The Solar. Do you have a battery welder project that deserves a spot in Hackaday’s rotation? By all means, send it over to the Tip Line!