Big Nerf Bazooka Packs A Wallop

November 20, 2020 by Lewin Day 4 Comments

Nerf blasters are a fun toy, often confiscated from children once they hit one too many precious ornaments around the home in the midst of battle. [Ivan Miranda] is bigger than most children however, and set about building a much larger blaster.

The bazooka-like design uses a several meters of 160mm PVC pipe, firing “darts” constructed out of foam yoga rollers and buffing pads. The build uses a littany of 3D printed components in its construction, both as part of the firing mechanism and as jigs to help machine the pipe. A large plunger is used to propel the darts, which is pulled back against the tension of thick rubber tubes before being released by the trigger mechanism.

It’s an intimidating device, to be sure. However, we suspect its short range, huge size, and slow reload time should stop it from breaking the meta-game at your local Nerf battles. That said, we still wouldn’t want to take a shot from this bad boy to the head. Hackers do love a good Nerf build, and they’re particularly popular in sentry applications. Video after the break.

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Procedurally Generated Trees

November 20, 2020 by Matthew Carlson 16 Comments

As the leaves fall from the trees here in the Northern Hemisphere, we are greeted with a clear view of the branches and limbs that make up the skeleton of the tree. [Nicolas McDonald] made a simple observation while looking at trees, that the sum of the cross-sectional area is conserved when a branch splits. This observation was also made by Leonardo Da Vinci (according to Pamela Taylor’s Da Vinci’s Notebooks). Inspired by the observation, [Nicolas] decided to model a tree growing for his own curiosity.

The simulation tries to approximate how trees spread nutrients. The nutrients travel from the roots to the limbs, splitting proportionally to the area. [Nicolas’] model only allows for binary splits but some plants split three ways rather than just two ways. The decision on where to split is somewhat arbitrary as [Nicolas] hasn’t found any sort of rule or method that nature uses. It ended up just being a hardcoded value that’s multiplied by an exponential decay based on the depth of the branch. The direction of the split is determined by the density of the leaves, the size of the branch, and the direction of the parent branch. To top it off, a particle cloud was attached at the end of each branch past a certain depth.

By tweaking different parameters, the model can generate different species like evergreens and bonsai-like trees. The code is hosted on GitHub and we’re impressed by how small the actual tree model code is (about 250 lines of C++). The power of making an observation and incorporating it into a project is clear here and the results are just beautiful. If you’re looking for a bit more procedurally generation in your life, check out this medieval city generator.

A Motorized Rotary Shop Table From Scratch

November 20, 2020 by Tom Nardi 8 Comments

As we’ve seen over the years, it’s possible to bootstrap your own metalworking shop using little more than a pile of scrap steel, a welder, and an angle grinder. With time and dedication, you can build increasingly complex shop tools until you’ve got yourself a nice little post-apocalyptic workshop. It’s the whole idea behind the [Workshop From Scratch] channel, and we never get bored of seeing his incredible backyard engineering.

But eventually, you’ll have built all the basic stuff. What then? Well, as [Workshop From Scratch] shows in a recent video, you can start working on the luxuries. Do you need a motorized table that will let you spin the workpiece and position it an at arbitrary angle? No, probably not. But as the video after the break shows, it’s certainly a handy thing to have around the shop. We especially like how he uses it to quickly and easily produce nearly perfect circular welds.

Note the welded standoffs used to hold on the lid.

From a technical standpoint, this is perhaps one of his more straightforward builds. But at the same time, the attention to detail that he puts into even this “simple” design is phenomenal. Nothing is wasted, and cutoff pieces from one section are often used in imaginative ways elsewhere.

[Workshop From Scratch] is truly a master of working with what you have, and this project is a perfect example. We especially like the tilt mechanism, which uses a massive leadscrew spun by a wiper motor salvaged from an Audi A8 B4. It looks like a fair amount of new hardware went into the control electronics, but even still, we have no doubt that the cost of this build is well below the purchase price of a commercial alternative.

Much like his hydraulic lifting table or motorized plasma cutter, not everyone is going to need something this elaborate in their home shop. But his magnetic vise and mobile drill press cart are far more approachable for the home gamer. Of course even if you don’t follow along and build your own versions of his tools, it’s always worth tuning in just to see him work.

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No Wonder These Projects Won The Circuit Sculpture Contest

November 20, 2020 by Mike Szczys 5 Comments

There are five winners of the Hackaday Circuit Sculpture contest, and every one of them comes as no surprise, even in a tightly packed race to the top.

Beginning with the gorgeous photo above, we have [Eirik Brandal’s] waldian being named the most beautiful. Imagine this hanging on your living room wall, then head over and listen to the video demo as it’s light-actuated synthesizer chimes like distant (or maybe not so distant) church bells. This isn’t a one-off dip into circuit sculpture for [Eirik], we featured his broader body of work back in 2018, all of it worth checking out in more depth.

The glowing mask is actually made of PCB. The seams are secured with super glue bolstered with baking soda. The labor behind this one is intense. As we mention back in September, the project took place over about two years, mostly due to the sheer volume of cutting and sanding [Stephen Hawes] needed to do to bring together so many pieces. This one grabbed him the most artistic award.

[Jiří Praus] takes the top spot for best video with his luminescent RGB LED sphere. We swooned over this one when it first dropped back in December. [Jiří] shows off a combination of patience and ingenuity by using a 3D-printed mold to hold each LED while he soldered brass rod in place to serve as both electrical and mechanical support.

Speaking of molds, one of the challenges was to show off the best jig for creating a circuit sculpture. [Inne’s] Soft Soldering Jig provides the channels needed to keep crisp right angles on the brass rod as you work, with voids to position components at intersections for soldering. Drawing on the advice of numerous circuit sculpture success from people like [Mohit Bohite] and [Jiří Praus], he was looking for a way to easily position everything on a surface that would not be burnt by the soldering iron. The answer comes in the form of Silicone jigs made with 3D-printed molds.

Finally we have the Binary Calculator project which won the most functional award. While it does operate as a binary calculator, the beauty of it is not to be overlooked. Among its many attributes are a set of cherry-wood keycaps that were milled for the project and a bell-jar display stand where the calculator rests and serves as a binary clock when not in use. You may remember seeing our feature of this project last week.

As prizes, the binary calculator, orb, and wall sculpture creators will each be receiving $200 in goodies from Digi-Key who sponsored the contest and will be featuring entries in a 2021 wall calendar. Creators of the soldering jig and the PCB mask will receive a $100 Tindie gift card.

Desktop Wind Tunnel Brings Aerospace Engineering To The Home Gamer

November 20, 2020 by Mike Szczys 10 Comments

Computer simulation is indispensable in validating design and used in every aspect of engineering from finite element analysis to traffic simulation to fluid dynamics. Simulations do an amazing job and at a fraction of the time and expense of building and testing a scale model. But those visceral ah-ha moments, and some real-world gremlins, can be easier to uncover by the real thing. Now you don’t need a university research or megacorp lab to run aerodynamic study IRL, you can just build a functional desktop wind tunnel for a pittance.

[Mark Waller] shows off this tidy little design that takes up only about two feet of desk space, and includes the core features that make a wind tunnel useful. Air is pulled through the tunnel using a fan mounted at the exhaust side of the tunnel. The intake is the horn-like scoop, and he’s stacked up a matrix of drinking straws there to help ensure laminar flow of the air as it enters the tunnel. (The straw trick is frequently used with laminar flow water fountains). It also passes through a matrix of tubes about the diameter of a finger at the exhaust to prevent the spin of the fan from introducing a vortex into the flow.

For analysis, five tubes pipe in smoke from an vape pen, driven into the chamber by an aquarium pump. There’s a strip of LEDs along the roof of the tunnel, with a baffle to prevent the light shining on the black rear wall of the chamber for the best possible contrast. The slow-motion video after the break shows the effectiveness of the setup.

Whether you’re a Hackaday Editor cutting their own glider wing profiles using foam and hot wire, or just want to wrap your head around how different profiles perform, this will get you there. And it’ll do it at a fraction of the size that we’ve seen in previous wind tunnel builds.

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Ask Hackaday: What Tools Do You Really Need For A Life On The Road?

November 20, 2020 by Jenny List 45 Comments

How do you dispose of an old hard drive? Inventive stories about heat and flame or industrial shredders will no doubt appear in the comments, but for me I just dismantle them and throw the various parts into the relevant scrap bins at my hackerspace. The magnets end up stuck to a metal door frame, and I’m good to go. So a week or so ago when I had a few ancient drives from the 1990s to deal with, I sat down only to find my set of Torx and Allen drivers was missing. I was back to square one.

What A Missing Tool Tells You About Necessities

Clint Eastwood always seemed to have just what he needed, why can I never manage it! Produzioni Europee Associati, Public domain.

Life deals an odd hand, sometimes. One never expects to find oneself homeless and sofa-surfing, nearly all possessions in a container on a farm somewhere. But here I am, and somewhere in one of those huge blue plastic removal crates is my driver set, alongside the other detritus of an engineer scribe’s existence. It’s all very well to become a digital nomad with laptop and hotspot when it comes to writing, but what has the experience taught me about doing the same as a solderer of fortune when it comes to hardware? My bench takes up several large removal crates and there is little chance of my carrying that much stuff around with me, so what makes the cut? Evidently not the tools for hard drive evisceration, so I had to borrow the set of a hackerspace friend to get the job done. Continue reading “Ask Hackaday: What Tools Do You Really Need For A Life On The Road?” →

Hackaday Podcast 094: Fake Sun, Hacked Super Mario, Minimum Viable Smart Glasses, And 3D Printers Can’t Do That

November 20, 2020 by Mike Szczys 3 Comments

Hackaday editors Elliot Williams and Mike Szczys traverse the hackerscape looking for the best the internet had to offer last week. Nintendo has released the new Game & Watch handheld and it’s already been hacked to run custom code. Heading into the darkness of winter, this artificial sun build is one not to miss… and a great way to reuse a junk satellite dish. We’ve found a pair of smartglasses that are just our level of dumb. And Tom Nardi cracks open some consumer electronics to find a familiar single-board computer doing “network security”.

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (~60 MB)