Laser Toting Robot Taunts House Cat

March 11, 2013 by 26 Comments

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[Rodney Lederer] and his cat were bored after moving to a new city. He fixed that for both of them by taking on this project which turns a Wowwee robot into feline entertainment.

It’s no secret that cats have a weakness for the little red dot produced by a laser pointer. [Rodney] put that trait to work by automating the movement of a red laser pointer. After mounting it on a servo motor he got down to work programming an Arduino to move it in a playful manner. But it wouldn’t have been much fun if the this was only capable of preprogrammed patterns, so he also included an IR proximity sensor to help give the thing interactivity. Add to that the treaded robot base and you’ve got mobile cat entertainment. The proof is in the video after the break… the cat is certainly having fun chasing the dot. [Rodney] plans to work a bit more on his code so that the motions of the laser dot include a lot of different patterns to keep things exciting.

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Variable Frequency Laser Using Shaken Ball Bearings

September 19, 2012 by 22 Comments

Lasers normally emit only one color, or frequency of light. This is true for laser pointers or the laser diodes in a DVD player. [Kevin] caught wind of state-of-the-art research into making variable wavelength lasers using shaken grains of metal and decided to build his own.

When [Kevin] read a NewScientist blog post on building variable frequency lasers built with shaken metallic grains, he knew he had to build on. He dug up the arxiv article and realized the experimental setup was fairly simple and easily achievable with a bit of home engineering.

[Kevin]’s device works by taking thousands of small ball bearings and putting them in a small vial with Rodamine B laser dye. To vibrate the particles in the dye, [Kevin] mounted his container of dye and bearings on an audio speaker and used a frequency generator to shake the ball bearings.

When a small 30mW green laser shines through the vial of ball bearings and dye, the laser changes color to a very bright yellow. By vibrating the vial at 35 to 45 Hz, [Kevin] can change the frequency, or color of the laser.

[Kevin] can only alter the frequency of the laser by about 30 nm, or about the same color change as a reddish-orange and an orangish-yellow. Still, it’s pretty amazing that [Kevin] was able to do state-of-the-art physics research at home.

Sadly, we couldn’t find any videos of [Kevin]’s variable frequency laser. If you can find one send it in to the tip line and we’ll update this post.

Build Your Own Line Laser For 3D Scanning

March 2, 2012 by 32 Comments

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[Valentin] wanted to experiment with 3D scanning some objects he had around the house, but says he didn’t want to buy a line laser for the project since they are pretty expensive. Fortunately, he had some random components sitting in his parts bin, and he was able to build his own line laser without spending a ton of money.

His tutorial actually covers two different methods of building line lasers, both of which use parts that you likely have on hand already.

His first build involves gluing a small square mirror to a flat platform, which he then mounted on a salvaged DC motor. Once the motor starts spinning, the cheap laser pointer he has aimed at the mirror draws a perfect line across whatever medium he is scanning.

His second line laser uses parts donated from an old hard drive that he no longer used. He removed the drive’s read head from the chassis and mounted a small mirror on the actuator arm before firing up his laser. With the laser aimed at the mirror, he applied an unspecified AC current to the motor, which caused it to oscillate and draw a line similar to his first setup.

While they might not be professionally-built scanning lasers, [Valentin’s] efforts produced some decent images, as you can see on his site.

Continue reading to see a short video of his DC motor laser line in action.

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Full Color Laser TV

December 31, 2011 by 23 Comments

Back in 2001, [Helmar] made an awesome monochrome video display out of a red laser pointer and a spinning 18-sided mirror. Blue and green lasers are much less expensive than they were a decade ago, so [Helmar] decided to go full color with his laser projector. (In German, so fire up Chrome or get the Google translation)

The ancient website for [Helmar]’s green-only projector goes over the principles of operation. A single laser shines onto a multi-faceted polygonal mirror. This is reflected onto another mirror that provides the reflection for each line in a frame of video. Earlier this year, [Helmar] hacked up a red and blue laser to complement the preexisting green laser. The end result is an RGB projector powered by friggin’ lasers.

As far as we can tell, the projector only has composite input; the attached DVD player provides all the signaling for that. Amazingly, [Helmar] didn’t use a microcontroller for the circuitry. All the electronics are simple logic gates. Really amazing if you ask us.

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Laser Level Tripod Made From Recycled Parts

October 14, 2011 by 6 Comments

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[msuzuki777] is a self-proclaimed “Lazy Old Geek” with way too much free time on his hands. He recently picked up a laser cross and figured that he would use some of that time to make a laser tripod for various projects around the house.

He pulled out an old camera tripod, and modified an unused CD jewel case so that it could be screwed onto the traditional camera mount. He added three bolts to the platform, on which he mounted another CD case, letting him adjust both the laser platform as well as the tripod.

He put together a simple power supply for the laser, and then mounted it on a pair of CDs sandwiched on top of one another. The CD platform was then popped onto the guts of an old CD player, allowing him to spin his laser pointer in any direction without having to re-level it.

The laser cross tripod certainly looks a bit complicated, but [msuzuki777] says it works a treat, allowing him to easily hang pictures and the like. He also mentions that he wants to throw an Arduino at it to automate the leveling process, which is something we’d love to see.

Win A Laser Cutter By Playing With Light

October 7, 2011 by 19 Comments

Buildlounge and Full Spectrum Laser have decided to give away a laser cutter to whoever comes up with the best project involving light.

The contest is in part sponsored by  adafruit industries. The focus of the contest is light – just design something around light, submit it, and you’re in the drawing for your own laser cutter. A solar oven, photophone, solar fiber-optic lighting and hacking apart an old overhead projector are suggested on the contest page, but the winning project will probably be much cooler.

Entries are due by January 1st. First prize is Full Spectrum Laser’s 40 Watt laser cutter, second is an awesome green laser pointer from Wicked Lasers, and third prize is an EL wire starter kit from Adafruit. Entries are due by January 1st, so we expect to see a lot of awesome submissions on the Hack A Day tip line between now and New Years.

Update: Laser-powered Auto Focus Assist Version 2

June 2, 2011 by 12 Comments

We don’t know if our feature from a couple of days gave [Adrian] a kick in the pants, or if he was just on target to finish is writeup this week, but he’s posted about version 2 of his laser auto focus assist project.

The original idea was to use an unfocused laser pointer dot to give his DSLR auto focus feature a kick in the pants since the built-in light doesn’t come back on when photographing moving subjects. The original version worked, but he had to operate the laser manually and the hardware was kind of spread out all over the camera.

The latest version (2.0) can be seen above, housed in a project box that mounts to the hot shoe and keeps everything together in one package. The laser operation is now automatic, coming on when the shutter trigger is depressed half way, or when the auto focus enable button is depressed. The controls on the project box include an on/off switch as well as a potentiometer which varies the intensity of the laser.

It looks like this won’t be the last version of the hardware that we see. [Adrian] covers a few outstanding problems in his post. Most notably, the laser light is still a bit too strong. At a recent live event, another photographer took issue with the fact that his images included the red splotch from [Adrian’s] diy hardware.