A couple of years ago I was at an estate sale with my mom and picked up this interesting Weston 1293 Digital Volt Meter. Could not resist nixie tube test equipment for $15.

Weston 1293 DVM

I'd learned a lot about how it worked from a web page describing the Weston 1294, though that web page appears to be completely gone from the internet without a trace—not even a page is cached in the Internet Archive. I hope that site has a shorter hiatus than mine did…

Internals (analog and digital boards)

It had been sitting on my shelf without much use in the interim because it was hard to use with just bare wires soldered on a connector on the back, so finally I've gotten around to building an enclosure for it. I also found an original manual for the Weston 1294 on eBay, which provided more context, though there are numerous differences.

Enclosure Construction

Construction was relatively straightforward, with internal wiring mostly implemented with crimped spade termination and plenty of heatshrink. The most interesting part of the construction was cutting out holes in the aluminum front and rear panels of the enclosure. First I marked the cutouts using blue masking tape. Then I roughed out the holes with a drill and a jigsaw, finally finishing it up using a file. I think this practice of roughing out a hole and filing it to the line must be a standard technique, but I didn't really know how to do this until I saw the amazing craftsmanship on the ClickSpring YouTube channel, where this technique is used a lot.

Complete!

Recently I purchased a Melles Griot Omnichrome 643 laser on eBay (as noted in my laser inventory). I was happy to find it arrived in great condition after making the long trip from Canada. I had long wanted an Argon-Krypton laser capable of producing a wider slice of the spectrum—"whitelight"—but they seem to be quite a bit more rare than plain old Argon-ion lasers, and usually more expensive. Got lucky with this one.

It came with almost everything including the laser itself, power supply, cooling fan unit, and even a printed manual. It was almost ready to run out of the box, but I needed a cable that connects the laser head to the cooling unit, an air duct, and also a way to plug it in; it draws 20A @ 240V.

First I wired up a 10 gauge extension from my electric clothes dryer outlet with a NEMA 10-30 plug to a NEMA 6-20R receptical. I ordered 25ft of 10/3 SOOW cable and the plug from Amazon and picked up a "handy box" and the receptical at Lowes. Working with these heavy, flexible SOOW cables reminds me of my days in highschool technical theater…

I couldn't find one on eBay, so parts for the other cable required a new crimper (Engineer PAD-01), a Digi-Key order, and tracking down some 18/6 SOOW at a good price. Fortunately it was easy to defeat the fan interlock with a jumper and use another blower I had for my other Argon laser in the mean time.

So after just a bit of wiring and basic external cleaning I was able to get it running in top shape. I made a new jumper remote plug to run it in constant-current mode and walked the mirrors to get the peak output up to about 83mW at max current. I figure the cross-continent shipping probably wasn't great for mirror alignment, but no worries now. The specific model number is 643-OLYM-AO3, which I suspect means it came from an Olympus confocal scanning microscope, but have no explicit specifications for the unit. I received the tube with about 570 hours on the run time meter, so it is far from new but still has great light output. Anyway, on to the pictures!

One day I think I might be interested in getting RGB optics instead of the RYB this unit comes with so that it'd be more appropriate for laser display purposes. Some folks suggest that it is best to appreciate the yellow-green line for what it is and avoid the trouble. Guess we'll see if I come across the right kind of output-coupler optic. Next project is to build a small digitally-controlled remote for the 171-B power supply.

After a hiatus of more than 5 years, I’ve resurrected my website! I’m hoping to share some project stories, add back some archival content from the old site, and have a place to share things I learn.

Years ago I took down my website because my VPS had been exploited, I think due to an outdated version of Wordpress. This new one should be more reliable; I’m using Jekyll hosted on Amazon AWS using S3 and CloudFront, which made it easy to adopt SSL and HTTP/2. I wrote a custom Jekyll plugin to handle automatic thumbnail generation for images and Lightbox stuff. Fun new project!

I’m slowly bringing back some old content on the blog, such as my post about building a Blu-Ray Laser Pointer, and have refreshed some of the content in the Lasers and Panoramas sections.

I'm excited to note I've updated my Publications page with an exciting bit of work that was recently published in IEEE MultiMedia!

Helen and Heiko asked me to contribute to this article about the Nuage Vert project. Abstract included and link to IEEE article below. Check it out in your July-September issue of IEEE Multimedia or get it online (fee based).

Editor's Note

Nuage Vert [Green Cloud] is a major environmental artwork that engages light and public participation. A stunning and important work, Nuage Vert has won many accolades and several prestigious prizes, including the 2008 Golden Nica in Hybrid Art from Ars Electronica, the 2008 Green Prix from ZeroOne, and the 2009 Award from the Environmental Art Foundation. The implementation process is particularly interesting as the team found new and successful ways to work with lasers that will benefit future artists.

—Norie Neumark

Today I had a great time going to Maker Faire in San Mateo. It really is inspirational for one's own projects to see other neat work being done.

I'm currently busy working on a couple of things, but I realize it has been a while since I've posted updates on anything I've done. Back in September of last year I put together a DMX-512 level converter breakout board for my EasyLase USB.

 

I'd previously ported and debugged the DMX portion of the driver for the board just using TTL level loopback adapters. I also went on to build the Wonderwall project using the DMX output of the EasyLase, but the level shifter and RS-485 transceivers were all on a solderless breadboard. That needed to be corrected. :)

I'm rather proud of the size of the board--especially being made of all through-hole components. It neatly plugs in to the existing headers, and I think it looks right at home where it has been mounted on the board. All the schematics to build one for yourself are available on the Müller Elektronik website. Enjoy!