Hackaday Links: Sunday, April 21st, 2013

hackaday-links-chain

Regular reader and master hacker [Bill Porter] got married. Congratulations [Bill] and [Mara]! The two of them just couldn’t leave their soldering irons at home. The actually swore their vows by soldering together a circuit during the ceremony (blinky wedding dress, el wire tuxedo, and all).

[Kevin] sent in a link to [Red Fathom's] hacked Wacom tablet. It’s the screen from a Wacom-enabled laptop brought back to life with a Teensy and an LVDS interface module.

The Neato XV-11 is able to find its charging station when the batteries run low. [Derek] figured out that you can make a second station using some reflective tape.

If you use your drill a lot you’ll eventually break the rubber thing that holds the key to the chuck. Here’s a way to 3D print a replacement.

[Torxe] put eight floppy drives to use as a polyphonic Arduino-controlled MIDI player. And while we’re on the subject of Arduino controlled projects you should take a look at this web-interface to tell you if the foosball table is being used.

And finally [Th3 Bad Wolf] sent in this link to a milling machine built out of LEGO. It is able to mill floral foam and uses a lathe-like setup for one of the table axes.

Measuring the lifespan of LEGO

lifespan-of-LEGO

How many times can you put two LEGO pieces together and take them apart again before they wear out? The answer is 37,112. At least that’s the number established by one test case. [Phillipe Cantin] was interested in this peculiar question so he built the test rig above to measure a LEGO’s lifespan.

The hacked together apparatus is pretty ingenious. It uses two servo motors for testing, each driven by the Arduino which is logging the count on an SD card. One of the two white LEGO parts has been screwed onto an arm of the upper servo. That servo presses down onto the mating piece which is sitting inside that yellow band. Look close and you’ll realize the yellow is the handle end of an IC puller. When the post on the lower servo is moved toward one arm of the puller it grips the lower LEGO piece tightly so that the upper servo can pull the two apart. In addition to the assembly and disassembly step there’s a verification step which raises the mated parts so that a reflectance sensor can verify that they’re holding together. [Phillipe] let the rig run for ten days straight before the pieces failed.

Don’t miss his video description of the project after the break.

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LEGO stylus solves Ruzzle tablet game

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This grid of letters is a puzzle game for tablet devices called Ruzzle. The contraption attached is an automated solver which uses LEGO Mindstorm parts to input the solutions on the screen. [Alberto Sarullo] is the mastermind behind the project. As you can seen in his demo video after the break he has a flair for the cinematic. But he makes you work a little bit to discover the details of his project.

His post gives a general overview of how this works. A Linux box takes a screenshot of the Ruzzle board. After processing the graphics with Imagemagick he uses Tesseract — an Optical Character Recognition program — to figure out which letter is on each square of the playing area. From there NodeJS is used to discover all possible words with the help of a dictionary file. The final solutions are pushed to the LEGO parts to be traced out on the touch screen with a stylus. The nice thing is that he published all of his code, so you can drill much deeper into the project by pawing through his repository.

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LEGO LP Player

This LP player is made entirely out of LEGO parts. It plays the songs encoded on each record, but not by using a stylus in a groove. Instead, each LP has a color code on the bottom of it which is interpreted by the optical sensors underneath.

In addition to its functionality [Anika Vuurzoon] made sure that the build looked the part. The horn is a nice touch, but you’ll also appreciate the rotating mini-figures on the front side of the base. To the right there is a hidden door that provides access to the NXT brick which drives the system. New records are produced using a couple of different tools. First off, the song is written using Finale, a mature musical notation program. That is exported and run through a second program which produces the colored disc design which is applied to the records. You can hear the songs for yourself in the clip after the break.

If LP playing toys are right up your alley you’ll want to check out this 3D printed record hack for a Fisher Price toy.

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LEGO Record Player

Some people claim that the sound of vinyl is superior to digital playback. While this hack wont win any awards for audio quality, [Ryan]‘s LEGO Record Player is a unique use of one of our favorite toys. Most of the components including the tone arm, counterweight, and base, are built entirely of LEGO. A large gear from an educational construction set is used for the platter. Unfortunately, the rotation isn’t terribly smooth, and the playback is rather distorted.

The turntable uses a standard cartridge and stylus, which should allow it to be connected to any receiver with a phono preamplifier. Using these off the shelf parts, it’s possible to build the mechanical components a turntable out of a variety of things. As the video demonstrates, getting the platter to turn correctly is a bit of a challenge.

Check out a video of the wobbly playback featuring Cindy and Bert after the break.

Via Make

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Tens of thousands saved by building a BAM microscope out of LEGO

A Brewster Angle Microscope (BAM) can run you around $100,000. If you don’t have that lying around you could just use some LEGO pieces to build your own. Having been faced with no budget to buy the hardware, and needing the data to finish his PhD, [Matthew] figured out a way to build something passable on the cheap.

These microscopes bounce a light source off of a pool of water and into the lens of a camera. The thing is the angle of the sender and receiver must be just perfect at 53.1 degrees. [Matthew] was able to afford a used camera, and started experimenting with some lab equipment to mount the rig. But he just couldn’t get the adjustments right. Since he had to move the mounting hardware by hand it was impossible not to over or under shoot the corrections. But then he had a eureka moment. LEGO pieces have very accurate tolerances, and you can get geared and motorized parts. He leveraged the quality of the toy into a BAM whose alignment can be tweak with great precision.

It may not look like much, but you can see stearic acid floating through the microscope’s field of vision in the clip after the break. This is exactly the type of observations he needed to perform. Of course if you just need a microscope you can use a laser and a drop of water.

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17-stage Great Ball Contraption must use all the LEGO pieces

Looking at this 17-stage Great Ball Contraption makes us think that [Skiyuky] should be working in industrial automation. The build, which has been assembled from an untold volume of LEGO parts, moves a reservoir of round plastic balls around a circuit. Each module exhibits a different mechanical way of handling the parts. It’s certainly not the first GBC we’ve seen, but the previous offering combined stages from many different makers. [Skiyuky] built this one all himself over the last two years.

The video after the break starts off at the main depository of tiny soccer and basketballs. To help illustrate how long it takes to move around the entire circuit [Skiyuky] adds a red and blue ball which are both easy to spot. From there it’s a Willy Wonky type of ride through all manner of contraptions. We’re struck by accuracy and efficiency with which all of the stages operate.

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