Parts were approximately $60, using the PS3 replacement drive assembly and other recommended items from various how-tos on the Internet. Essentially, the diode is removed from the disc assembly, installed in an old 5mw red laser housing, and connected to a brand new LM317 based power supply. I am well on my way to building an adorable little blue laser pointer for far under $100. It is really more purple than blue, but it looks pretty cool. Right now I’m still too afraid to crank up the juice to see how bright it can get.

According to some random forum post:

lasing threshold: 27-28ma
working current/voltage: 4.4v @ 30-40ma
output:
30mA 2.68mW
35mA 9.45mW
40mA 13.3mw
45mA 17.0mW


I can at least verify the lasing threshold was accurate–I do not have the appropriate equipment to measure power output.

And of course, I couldn’t have done it without information from Sam’s Laser FAQ, specifically the article examining Blu-Ray Laser Diodes.

photo credit HeHe

The project is going on display February 22-29 in Helsinki. I encourage you to go check it out more in depth at www.nuagevert.org.

For the project, I ended up creating a Java wrapper for the libEasyLase driver for OS X. It is now possible to get laser output on the EasyLase USB from inside a Java app on the Mac. Please contact me if you’re interested using this.

The build is Universal and has been tested on PPC and x86. The installer includes libftd2xx, a necessary library from FTDI. It is working well with libftd2xx version 0.1.3; Version 0.1.0 is the current released version, and I expect FTDI to update this soon.

Please let me know if you’re using this driver to access an EasyLase USB on the Mac, I am happy to help with usage and development of laser software on Mac OS X.

Download EasyLase USB Driver v1.0 (Universal) for Mac OS X:

libEasyLase.dmg.

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I was happy to see a number of ACM folk braved the extreme cold weather to play Asteroids on exterior walls at the Krannert Center for the Performing Arts, an excellent venue which I intend on visiting again next Friday, when my good friend Erik will be playing Cello in the last orchestra concert of the semester.

This whole event turned out to be a quite a success with a Hot Cocoa + Helvetica reception afterwards, despite the fact that the software is still mostly a quick hack. I look forward to further development of additional laserware on the Mac.

Now just to write the real optimization code to make it work well… : )

Frankly, I’m not really interested in getting in to those politics. But one recent event got me–uhm…motivated–to enter the arena of playing classic vector games on a laser projector. It seems like a most natural thing to do and looks completely awesome. Even the high end graphics people at SIGGRAPH this year loved the ultimate saturation and archaic wireframe visuals generated by a laser projector playing vector games from ‘79 and the 80’s.

When Paul Debevec introduced the Electronic Theater showing we were fortunate enough to have at the NCSA building on November 8th, he excitedly highlighted the laser enabled MAME setup that they had installed when first showing these videos in San Diego. I was excited to hear this and even more pleased when he put up the photo of the renown laserists and others involved with getting the system working; Steve Heminover (who I’ve been lucky enough to meet), Matt Polak, and others.

I have an extreme amount of respect for the people involved here. They’re the world’s experts on laser display, and the production quality was fantastic, but I must admit through the whole video demo, I was thinking, “Hey, it can’t be that hard–everything is already in vector format. What’s the big deal.”

So last night after we got some ice cream at Cold Stone, despa and I got to coding. It took a good 2 or 3 hours to get MacMAME to compile. After that, in another couple of hours we hacked up a prototype of laserMAME using the EasyLaseUSB on Mac OS X. I know we’ve got the math wrong (we didn’t know the range of the x and y coords–and the documentation is temporarily unavailable on the MAME website), but we got Asteroids working with some display bugs.

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I think another couple of nights of hacking could make it really beautiful.

I apologize for the poor quality of the projection, images, and video, but I was so excited we got something working, I wanted to publish right away. I expect we’ll have much better results before, say, March 2008. More to come.

Nd:YAG, HeNe, Argon Ion

Freshly unladen of clutter, I felt free to fire up an array of three lasers for the first time in concert. The triad of chromes shone brightly across my apartment’s newly cleaned floor in all their spectral glory. Maybe this summer will afford the opportunity to mix the colors and draw some pretty pictures; what else would one do with such a source of white light?

First ILDA Test Frame output on EasyLase USB from my Mac.

I posted some additional videos and photos at http://www.acm.uiuc.edu/~hagedorn/EasyLase/

This represents good progress toward LaserLine 2.0’s core objectives. More information about what those objectives are, and how we’re progressing is available at our Trac site.

I’ll be spending whatever free time I have over the next couple of weeks implementing the optical position-detector system on the galvos (I finally gave up on the RF-PD) and fixing bugs in the EasyLaseUSB driver for Mac OS X. It is close, but still occasionally hangs; and that needs to be fixed completely. Engineering Open House is approaching quickly; so are due dates for assignments…

Alas I am afforded a bit of consolation in the opportunity to “dry-fit” the components of the galvo project before committing to final assembly. No thermal epoxy or cyanoacrylate, no worries when things need adjustment. I seized the opportunity and have included a number of pictures (inside this post) demonstrating the details of the assemblies, as they finally resemble something that will actually work.

The PD rotor was easy to get perfectly round with the following simple technique: 1) Cut out the disc roughly with scissors. 2) drill a hole perfectly in the center of the disc. 3) mount the disc on the Dremel using the abrasive-disc mount. 4) spin the disc against the sand paper or a file to round it, similar to the way a lathe works.

Of course there are plenty of additional photos in the Album. Enjoy!

Above: Interface, first output on Oscilloscope

In testing so far, it seems like it is going to be great, but there is plenty of coding to do yet to achieve the greatest performance. The card has plenty to give, and extra features like DMX512 In/Out–one less thing I need to buy!

Thus far, because the projector isn’t quite finished yet, I’ve been testing with a Tektronix 2440 Oscilloscope. My friend Sean helped code a 3d Torus(QuickTime video) demo. It worked quite well, but I’m still having trouble with FTDI’s D2XX driver for OS X version 0.1.0, perhaps the next version will solve some of the problems I’m having. Specifically, read and write calls are hanging when I know they shouldn’t.

I consider them stunning.

Key features include all-aluminum construction for optimal heat-dissipation as well as strategically placed mounting holes for circuitry or additional heatsinks. The should also provide flexible mounting surfaces for the galvos. It will be necessary to use thermal epoxy to glue the coils to the surface for maximum thermal conduction.

I really anticipate these will provide high-performance platforms for the rest of the components.

I am providing CAD drawings of the Base and Side parts in PDF format if you’d like to make them yourself as well. If you’ve like them in an editable format, just let me know.

1. Ball Bearings – 2×6x2.5 Hybrid Ceramic/Stainless Steel Ball Bearings from VXB for $4.95/each.
   These bearings are designed to be especially “smooth” and have an ABEC-5 rating. In searching for bearings, I learned that all is not contained in the ABEC rating, and the ceramic properties of these bearings provides greater smoothness; though they are not rated for extremely high lateral loads. This is not a problem with a couple-gram rotor. Perhaps less expensive bearings would be adequate, however this is a vital component so it was probably worth it.
2. Mirrors – small and thin first surface mirrors off of eBay.
3. Set Screw Collars – 2mm Metric Set Screw Collars model MC-02 manufactured by Climax Metal Products. Purchased at Fastenal for $1.04/each available only in the (especially cool looking) Black Oxide Finish.
4. Machined Galvo Frames! You’re going to have to come up with something for these…

Left to right: US quarter dollar coin, bearing, mirror, and collar.

Completely Offtopic

I highly recommend the following guide for people new to IRC and the unicies:

A Guide to Efficiently Using Irssi and Screen

I’ve been in a bunch of IRC channels lately, including #laserfreak on irc.wiredirc.net, a german channel discussing laser tech, and a bunch of other channels around UIUC.