DIY 3D Projector From An LCD

We’ve shared many home made projectors in the past, but we think this might just be the first home made 3D projector!

[Nicholas] has created a wonderful write up on this project on his blog, and in an Instructable, and even more details are available on the original forum post (in French though).

To sum it up though, he’s using an old LCD from a broken laptop, split into two halves. By using a Fresnel lens and two separate optical lenses that are adjustable he can combine the two images (top and bottom of the LCD) on the wall. Then by adding a polarization filter to each lens, he can reuse the cheap 3D goggles from the cinema for his own setup to see in 3D! This style of passive 3D does require a special projector screen to keep the polarization intact — he’s using a Da-Lite Silverlight screen, whose metallic surface ensures the polarization is kept the same.

It’s a great project and is definitely worth checking out. If you’re in the mood for a smaller form factor projector, it’d be worth checking out this one we covered quite a few years ago!

Get Tangled Up In EL Wire With Freaklabs

[Akiba] over at Freaklabs has been working with electroluminescent (EL) wire.  An entire dance company worth! We know [Akiba] from his post tsunami radiation monitoring work with the Tokyo Hackerspace. Today he’s one of the engineers for Wrecking Crew Orchestra, the dance company that put on the viral “Tron Dance” last year. Wrecking Crew Orchestra just recently put on a new production called Cosmic Beat. Cosmic Beat takes Wrecking Crew’s performances to a whole new level by adding stage projection mapping and powerful lasers, along with Iron Man repulsor style hand mounted LEDs.

As one might expect, the EL wire costumes are controlled by a computer, which keeps all the performers lighting effects in perfect time. That’s where [Akiba] came in. The modern theater is awash in a sea of RF noise. Kilowatts of lighting are controlled by triacs which throw out tremendous amounts of noise. Strobes and camera flashes, along with an entire audience carrying cell phones and WiFi devices only add to this. RF noise or not, the show must go on, and The EL costumes and LEDs have to work. To that end, [Akiba] He also created new transmitters for the group. He also changed  the lighting booth mounted transmitter antenna from an omnidirectional whip to a directional Yagi.

The EL wire itself turned out to be a bit of a problem. The wire wasn’t quite bright enough. Doubling up on the wire would be difficult, as the dancers are already wearing 25 meters of wire in addition to the control electronics. Sometimes best engineering practices have to give way to art, so [Akiba] had to overdrive the strings. This means that wires burn out often. The dance troupe has gotten very good at changing out strands of wire during and between shows. If you want a closer look, there are plenty of pictures available on [Akiba’s] flickr stream.

Continue reading “Get Tangled Up In EL Wire With Freaklabs”

8-Track Tapes As A Storage Medium

OLYMPUS DIGITAL CAMERA

Before [Woz] created the elegant Disk II interface for the Apple II, and before Commodore brute-forced the creation of the C64 5 1/4″ drive, just about every home computer used cassette tapes for storage. Cassette tapes, mind you, not 8-track tapes. [Alec] thought this was a gross oversight of late 1970s engineers, so he built a 8-track tape drive.

This actually isn’t the first instance of using 8-tracks to store data on a computer. The Compucolor 8001 had a dual external 8-track drive, and the Exidy Sorcerer had a tape drive built in to the ‘the keyboard is the computer’ form factor. It should be noted that nearly no one has heard about these two computers – the Compucolor sold about 25 units, for example – so we’ll just let that be a testament to the success of 8-track tape drives.

[Alec] installed an 8-track drive inside an old external SCSI hard drive enclosure. Inside is an Arduino that controls the track select, tape insertion and end of tape signals. Data is encoded with DTMF with an FSK encoding, just like the proper cassette data tapes of the early days.

On the computer side of things, [Alec] is using a simple UNIX-style, pipe-based I/O. By encoding four bits on each track, he’s able to put an entire byte on two stereo tracks. The read/write speed is terribly slow – from the video after the break, we’re assuming [Alec] is running his tape drive right around 100 bits/second – much slower than actually typing in data. This is probably a problem with the 40-year-old 8-track tape he’s using, but as a proof of concept it’s not too bad.

Continue reading “8-Track Tapes As A Storage Medium”

Creative Compulsive Disorder: Zina Nicole Lahr

[Zina Nicole Lahr] was an extremely talented artist, designer, puppeteer and maker, with a self-diagnosed condition that she liked to call Creative Compulsive Disorder which she describes as follows:

I suppose you could say I have a self-diagnosed condition called CCD, it’s Creative Compulsive Disorder where I have to make stuff all the time, and with whatever I have around me, so if it’s trash, or junk, or things that people would normally throw away, I try to find new ways to re-fabricate them into something useful and beautiful.

A true hacker at heart. She’s worked on tons of different projects in many different fields, even doing special effects and prop work for a TV show.

Unfortunately it is with great sadness that we share her story, as she recently passed away in a hiking accident.

What we are specifically sharing is a short 5 minute documentary about [Zina] which was made by her close friend [Stormy Pyeatte] a few months earlier for a school project. In this past week [Pyeatte] has re-cut the footage in an attempt to capture her personality, creativity and to celebrate her memory. She succeeded tremendously, our heartstrings cannot lie.

It’s a beautiful video about a beautiful soul. We wish we could have met you [Zina].

Continue reading “Creative Compulsive Disorder: Zina Nicole Lahr”

Retrotechtacular: Cathode Ray Tube (CRT) Manufacturing

This week we return to the grainy and un-color-corrected goodness that is synonymous with ancient video reels. [CNK] sent in a tip to a set of videos showing how Cathode Ray Tubes are manufactured on a massive scale. You’ll want to watch the pair of clips embedded below which total about 18 minutes. But there’s also some background to be found at this post from the Obsolete Technology Telley Web Museum.

The video presentation starts off with a brief overview of the way a color CRT works. It then moves to a factory tour, carefully showing each step in the process. The footage was shot in the 1960’s and because of that we catch a glimpse of some vintage equipment, like that used to measure the curvature of the CRT glass. You may be thinking that the world of CRT is in the past, but not so. We think there may even been a coming fad of producing them in your home lab.

Continue reading “Retrotechtacular: Cathode Ray Tube (CRT) Manufacturing”

Hanging Plotter With A Color Twist

hangbot

[Jack Boland], a mechanical engineer at the University of Wisconsin, built a cool hanging plotter project called HangBot. It’s a fairly standard setup, where he converts an image to G-Code files, and it is plotted using two stepper motors for control. We’ve seen vertical plotters before, but they tend to only have a single pen. [Jack] expanded this one to bring color into the mix by splitting an image into separate CMYK layers, and plotting each onto separate transparency film. When overlaid, they create something close to a full color image. His idea is to use this setup as a replacement for typical window signage.

Since it’s drawing a continuous line, he appears to be employing a grid instead of a traditional dot pattern. That, combined with the inaccuracy of a marker tip means resolution will be limited. Still, you can tell that he’s made a great start in this (albeit blurry) photo. Check out the video of it’s operation after the break.

Continue reading “Hanging Plotter With A Color Twist”

Ultrasonic Data Transmission With GNU Radio

When we hear GNU Radio was used in a build, the first thing we think of is, obviously, radio. Whether it’s a using extremely expensive gear or just a USB TV tuner dongle, GNU Radio is the perfect tool for just about everything in the tail end of the electromagnetic spectrum.

There’s no reason GNU Radio can’t be used with other mediums, though, as [Chris] shows us with his ultrasound data transmission between two laptops. He’s transmitting audio from the speakers of one laptop at 23 kHz. It’s outside the range of human hearing, but surprisingly able to be picked up by a cheap desktop mic connected to another laptop. His GNU Radio setup first converts a string of text to a 5-bit packet, modulates it with FSK, and bumps up the signal to 23 kHz. On the other end, the data is decoded by doing the same thing in reverse.

The setup is easily able to reject all audio that isn’t in the specified frequency range; in the video after the break, [Chris] successfully transmits a ‘hello world’ while narrating what he’s doing.

Continue reading “Ultrasonic Data Transmission With GNU Radio”