The Hovalin: Open Source 3D Printed Violin Sounds Great

January 2, 2016 by Adam Fabio 26 Comments

[Matt and Kaitlin Hova] have created The Hovalin, an open source 3D-printed violin. Yes, there have been 3D-printed instruments before, but [The Hovas] have created something revolutionary – a 3D printed acoustic instrument that sounds surprisingly good. The Hovalin is a full size violin created to be printed on a desktop-sized 3D printer. The Hovas mention the Ultimaker 2, Makerbot Replicator 2 (or one of the many clones) as examples. The neck is one piece, while the body is printed in 3 sections. The Hovalin is also open source, released under the Creative Commons Attribution Non-Commercial Share Alike license.

A pure PLA neck would not be stiff enough counter the tension in the strings, so [The Hovas] added two carbon fiber truss rods. A handful of other components such as tuners, and of course strings, also need to be purchased. The total price is slightly higher than a $60 USD starter violin from Amazon, but we’re betting the Hovalin is a better quality instrument than anything that cheap.

The Hovalin was released back in October. There are already some build logs in the wild, such as this one from [Emulsifide]. Like any good engineering project, the Hovalin is a work in progress. [Matt and Kaitlin] have already released version 1.0.1, and version 2.0 is on the horizon. Hearing is believing though, so click past the break to hear [Kaitlin] play her instrument.

Continue reading “The Hovalin: Open Source 3D Printed Violin Sounds Great” →

Simone Does Strange Things With Motors And Servos

December 29, 2015 by Adam Fabio 52 Comments

If DC motors are the “Hello World” of making things move, servo motors are the next logical step. [Simone Giertz] is following this exact path with the Wake-up Machine and her newly released Chopping Machine. [Simone] discovered that the best way to wake up in the morning is to be repeatedly slapped in the face by a robot. The Wake-up Machine was custom designed to do exactly that. Who could sleep through being repeatedly slapped in the face? A beefy gearmotor from ServoCity spins a Halloween prop arm round and round, providing “refreshing” slaps.

The system is triggered by an alarm clock. The clock’s alarm output is connected to an Arduino Uno. The Uno then activates a relay, which spins up the motor. [Simone] realizes that she could have skipped the Arduino here, but it was the path of least resistance in for this project. If the slapping hand isn’t enough to get you going, the Wake-up machine does have a secret weapon: It may just grab your hair, turning a video shoot into a painful ordeal.

Simone’s latest project is the Chopping Machine. ServoCity must have liked her first videos, as they’ve sponsored her for this project. The machine consists of two knives that … well, chop. Two high-powered servos are controlled by an Arduino Nano. The servos raise spring-loaded knives, which then drop down, chopping vegetables, fingers, and anything else in their path. The whole machine is built with aluminum channel stock, and a huge wooden cutting board. Of course, just building the machine wasn’t enough. [Simone] filmed a parody infomercial for any perspective Chopping Machine buyers, and to put fear in the heart of anyone named Chad.

Click past the break for a couple of [Simone’s] vlogs describing the machines.

Continue reading “Simone Does Strange Things With Motors And Servos” →

Nikon Resurrection: Repairing A Broken Lens

December 25, 2015 by Adam Fabio 14 Comments

Modern DSLR cameras are amazing devices. Mechanics, electronics, and optics, all rolled up in a single package. All that technology is great, but it can make for a frustrating experience when attempting any sort of repair. Lenses can be especially difficult to work on. One misalignment of a lens group or element can lead to a fuzzy image.

[Kratz] knew all this, but it didn’t stop him from looking for a cheap lens deal over on eBay. He found a broken Nikon DSLR 55-200mm 1:4-5.6 AF-S VR camera lens for $30. This particular lens is relatively cheap – you can pick up a new one for around $150 online. Spending $30 to save $120 is a bit of a gamble, but [Kratz] went for it.

The lens he bought mostly worked – the auto-focus and vibration reduction system seemed to be fine. The aperture blades however, were stuck closed. Aperture blades form the iris of a lens. With the blades closed down, the lens was severely limited to brightly lit situations. All was not lost though, as the aperture is a relatively simple mechanical system, which hopefully would be easy to repair.

Keeping screws and various parts in order is key when taking apart a lens. [Kratz] used a tip he learned right here on Hackaday: He drew a diagram of the screw positions on a thick piece of paper. He then stuck each screw right into the paper in its proper position.

Carefully removing each part, [Kratz] found a pin had slipped out of the rod that connects the lens’ internal parts with the external aperture control arm. Fixing the pin was simple. Getting the lens back together was quite a bit harder. Several parts have to be aligned blindly. [Kratz] persevered and eventually everything slipped into alignment. The finished lens works fine, albeit for a slightly noisy auto-focus.

It’s worth noting that there are service and repair manuals for many cameras and lenses out there in the dark corners of the internet, including [Kratz]’s 55-200 lens. Reading the repair procedures Nikon techs use shows just how many tools, fixtures, and custom bits of software go into making one of these lenses work.

Neil Movva: Adding (wearable) Haptic Feedback To Your Project

December 22, 2015 by Adam Fabio 4 Comments

[Neil Movva] is not your average college student. Rather than studying for exams or preparing to defend a dissertation, he’s working on a project that will directly help the disabled. The project is Pathfinder, a wearable haptic navigation system for the blind. Pathfinder is an ambitious project, making it all the way to the semifinals of the 2015 Hackaday Prize. Haptics, the technology of providing feedback to a user through touch, lies at the core of Pathfinder. [Neil] was kind enough to present this talk about it at the Hackaday SuperConference.

Continue reading “Neil Movva: Adding (wearable) Haptic Feedback To Your Project” →

Hacklet 89 – Star Wars Projects

December 18, 2015 by Adam Fabio 7 Comments

Star Wars is an inspirational force to be reckoned with. Few movie franchises have quite so many fans creating everything from elaborate cosplay outfits to fully functional robots. At the 2015 Hackaday SuperCon, former R2D2 driver Grant Imahara mentioned that LucasArts used to maintain a fleet of robots to be deployed at events. Once the execs realized hacker, maker, and hobbyist robots are now more advanced than the machines they built for the actual films, they mothballed the fleet. If you see R2 at a Star Wars event this season, it’s probably an enthusiast behind the controls. This week’s Hacklet is dedicated to the best Star Wars projects on Hackaday.io!

We start with [Nathan Gray] and Star Wars Nerf Targets. [Nathan] needed a Star Wars themed game for an event for the kids, and he needed it fast. [Nathan] built a Nerf shooting gallery game with a Star Wars twist. The idea is to shoot the bad guys with Nerf darts. Targets have two sides, so you never can be sure if you’ll see a storm trooper or a friendly Wookie. Hits are detected by piezoelectric disks on each target. A control panel starts the game, keeps score, and plays some great sound effects. An Arduino compatible Teensy 2.0 keeps everything running smoothly. [Nathan] reports that the game was a hit with the kids, and everyone else at the party. Even Grandma had to give the Star Wars Nerf Targets game a try!

Next up is Hackaday’s own [Brian Benchoff] with The Hackaday Prize Moisture Vaporator. The 2015 Hackaday Prize promo video called for something space related. Since Southern California has plenty of desert around, a moisture vaporator straight out of Tatooine was just what the doctor ordered. [Brian], [Matt], [Rich] and [Alek] handled most of the construction at the Hackaday Hackerspace in Pasadena. Final assembly was a team effort out in the field. The basic frame of the vaporator consisted of 1 x 3 lumber joined with pocket screws. An iron pipe served as the spine. [Brian] added plenty of greebles to give the vaporator just the right look. The result makes us long for a trip to Toshi Station to pick up some power converters.

[Davedarko] is up next with Towani Lifesign Wristdevice – Star Wars Ewoks. This was one of [Dave’s] earliest projects on Hackday.io, way down at project #616. He originally built it for the Sci-Fi contest we held in 2014. The Towani family was in the Ewoks movies, which were lesser known spinoffs of the original Star Wars films. The wristbands showing the family’s vitals were featured a few times in the movies. [Dave’s] version is more than a movie prop, it actually works. He’s using an open hardware pulse sensor along with an Arduino Mini to display status on a trio of LEDs.

Finally, we have [Enrico] with Our own BB-8 droid. BB-8 made a splash when he rolled out on stage during Star Wars Celebration. Everyone wondered how the original was done. We’ve since found out that the BB-8 uses Sphero’s technology to get around. However, many of the movie scenes were done with good old-fashioned puppeteer work. [Enrico] is building his own version of BB-8 using holonomic wheels inside the sphere, with a magnetically attached head. He’s planning to 3D print the major parts of his droid. So far, [Enrico] has started testing with magnets. A few printed plastic parts from his R2D2 build have been standing in for the BB-8 shell.

If you want to see more Star Wars projects, check out our new Star Wars project list! If I missed your project due to a great disturbance in the force, don’t be a nerf herder! 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! May the force be with you.

Rory Aronson On Documenting Open Source Projects

December 16, 2015 by Adam Fabio 7 Comments

Every project starts off with an idea. Sometimes those ideas are bigger than one person, or even a small group of people. That was the position [Rory Aronson] found himself in with Farmbot, his finalist entry in the 2015 Hackaday Prize. Documentation was key for [Rory]. Farmbot first came into the world in the form of a white paper. The paper included a request for collaborators, making this an open source project from day 0. Documentation has been important throughout the Farmbot project, so it was naturally the topic of [Rory’s] talk at the 2015 Hackaday SuperConference.

Continue reading “Rory Aronson On Documenting Open Source Projects” →

Rubber Tanks And Sonic Trucks: The Ghost Army Of World War II

December 16, 2015 by Adam Fabio 43 Comments

Winston Churchill once told Joseph Stalin “In wartime, truth is so precious that she should always be attended by a bodyguard of lies”. During World War II, the power of these bodyguards, in the form of military deception, became strikingly apparent. The German military was the most technologically advanced force ever encountered. The Germans were the first to use jet-powered aircraft on the battlefield. They created the enigma machine, which proved to be an extremely difficult system to break. How could the Allies possibly fool them? The answer was a mix of technology and some incredibly talented soldiers.

The men were the 23rd Headquarters Special Troops, better known as the Ghost Army. This unit was the first of its kind specifically created to deceive the enemy. Through multiple operations, they did exactly that. These 1100 soldiers created a diversion that drew German attention and gunfire to them, instead of the thousands of Allied troops they were impersonating.

The Ghost Army consisted of 4 distinct groups:

The 406th Engineer Combat Company Special were 166 “regular” soldiers – these men handled security, construction, and demolition.

603rd Camouflage Engineers were the largest group at 379. As the name implies, the 603rd was created to engineer camouflage.

3132 Signal Service Company consisted of 145 men in charge of half-tracks loaded down with massive 500 watt speakers which could be heard for 15 miles.

The Signal Company Special Formerly the 244th signal company, The 296 men of the Signal Company Special handled spoof radio communications. The Germans heavily relied on captured and decoded radio messages to determine the Allies’ next move.

Continue reading “Rubber Tanks And Sonic Trucks: The Ghost Army Of World War II” →