Wednesday, May 7, 2008

Maker Faire Pics

The Maker Faire was last weekend, and it was incredible! I think the natural teacher in me came out when I explained how the light pipe worked and why I decided to build it. Real fun! It was also wonderful to hear everyone's great ideas and suggestions. I'll be incorporating some of them into future prototypes for sure.

I must add that this fiber light pipe idea would have never been realized without the help of a handful of really great friends. Dan's stand design was inspired. Jess's etches were amazing. And Shay's big 'ol sign was eye catching and beautiful. Also, Shay stayed up with me until the wee hours of Saturday morning to make sure every part of the pipe was good to go. And then there were the folks that helped me man the stand. Jill was a perfect fiber light pipe spokesperson throughout the weekend, masterfully aligning the dish to the sun and rattling off optical factoids. Jess, Kale, Shay, Dan, Beanie, and Kim were there to take over when Jill and I had to take some breaks. I can't thank you guys enough!

For those of you who weren't able to see the fiber light pipe prototype at the fair, I'll explain the setup: We had a the solar collector mounted to a wooden 2-axis mount. A secondary mirror and heat absorbing glass were mounted to the collector. In the center of the collector was a rubber stopper with a five-foot bundle of eight fibers. These fibers led into an enclosed box (a 2'x2'x2' PVC pipe box covered in black fabric), and were attached to an acrylic pane with etches on it. The pane had reflective tape along the edges and it laid on top of a mylar-covered base. When the dish was aligned with the sun, the panel lit up the inside of the box.

Now for some pictures.

Figuring out how to set up:

The setup:

Explaining it to some folks:

The sun melted a plastic knob when the earth rotated:

Sunlight in a black box (no flash, no external light):

Jill and me toward the end of the day on Saturday:

One last thing. You can find the link to the Current TV video about me and the project here.

Friday, May 2, 2008

SF Chronicle + Fear of Fire

A beautifully written story about the Maker Faire just came out in the San Francisco Chronicle, and it features the light pipe project. Cool! Justin did a great job, but I'd like to add one tiny clarification. I did not actually build a periscope-like light pipe prior to this attempt, though I think the article makes it sound like I had. Probably what happened is this: during the interview for the story I described my thoughts on the potential ways to bring light to the living room, and that's when I described a more typical light pipe design. Not a big deal. The error just adds a little experience to my resume. Oh! And another thing: the picture of me is ridiculously serious. For a view of my not-so-serious personality and the project, check out a introductory video I made.

And now for some thoughts on heat:

The Maker Faire starts tomorrow, and there's still a bit of work that needs to be done. I'm mounting the secondary mirror as well as a heat filter tonight. I got the mirror from an amazing telescope store in SF called Scope City. The guys there were willing to listen to me drone on and on about how awesome this light pipe will be. Andthey sent me home with a mirror from a telescope and a ring holder with thumbscrews, something like the pictures in a previous post.

Steve from Scope City also highlighted the heat issues, which, of course, are crucial to consider. Initially, I was expecting to use a makeshift secondary mirror that probably wouldn't be extremely reflective, and, I thought that might keep the heat under control. But the telescope mirror is extremely high quality, so a lot of light and heat is going to be aimed at the fiber. Still, I should have been thinking about the heat problem from the beginning since people use these sorts of solar collectors to cook food and boil water.

So...I ordered heat-absorbing glass from an online vendor called Anchor Optics. It's rated to 300 C, and it should arrive today. That should keep the fibers from melting and the whole contraption from going up in flames.

UPDATE: So, that ridiculously serious picture in the Chronicle? It's been lollinated by my good friend Katie B.

Sunday, April 27, 2008

Amazing Weekend of Making Stuff with Friends

Thanks friends! You guys were amazing this weekend! Dan's plans for the solar reflector stand came to fruition; Jess found an amazing way to etch the acrylic; Shay designed the most perfect display for the booth at the Maker Faire; and Jill gathered supplies, sawed some bolts, and browned some amazing brats.

On Saturday, Dan and I got together at our friend Alice's place in Berkeley. We got to cutting some wood, drilling some holes and putting the stand together. Here's Saturday's video (1:44):

Sunday was kinda crazy because a guy from Current TV (Al Gore's television station based on user-generated content) came over to see the progress. Something that was cool: we lit the camera guy's cigarette from the solar collector. Then while the Current guy was wrapping up, the photographer from the San Francisco Chronicle dropped by. I think she got some good shots. A few of us capped off the day with some cheesy brats, grilled corn on the cob, and s'mores. Yum! (Sunday's video is coming.)

There's still plenty to do before the fair. On the reflector and stand side, I still need to mount the mirror and affix the fiber to the dish. I have some ideas and parts for this, it's just a matter of doing. Also, Dan's put a ton of work into the stand. This week, I'm going to try to pick up where we left off on Sunday and install the bearing so the dish can tilt to the sky smoothly and in style. Also, after Jess finishes etching the acrylic, I'll need to try to connect it to the fiber. In early tests with the fiber from the ACCRC, it looks like I need to make sure that the ends are flush with the pane. That could be tricky--or at least take some time and precision.

Then there's the display at the fair. We have a PVC-based frame for box that I'll cover with black fabric. I need to buy the fabric and make the curtains. I also need to work a little on the posters. I'm going to have one explaining the math behind parabolas and the physics of optical fibers. Also, information on solar collectors in general. Cool stuff!

Saturday, April 19, 2008

The Mount

I've been thinking a lot about the mirror mount lately. I have the parabolic reflector from Edmund Scientific (the 2-foot diameter dish). But I need to figure out a way to mount the mirror so that I can direct light from the focal point of the dish to the bundle of optical fiber in the center.

Enter: Edmund Optics (who is this Edmund guy, anyway?). I poked around this site for a while to look at optical mounts and I think I found one that I can emulate somewhat easily. It's essentially a ring with three screws (see picture below). You put the lens or mirror in the center and tighten the screws to secure it. I figure that I can take a lid to a jar and drill some holes for the three screws.

Once that's complete, the question still remains: how the hell do I secure the lens+mount to the dish in the right spot? Well, I've been thinking about this problem, and I think I have a decent solution. But let me back up. I have a rubber stopper that I'm putting in the hole in the reflector. I'm going to drill a hole in this stopper, about the size of the fiber, and shove the fiber through it. Okay, so that'll keep the fiber somewhat secure for testing purposes. Then I was thinking that I'd affix some large-gage wires (clothes hanger size or larger) to the stopper, pointing straight up. If I drill three or four more holes in the lens mount, then I can slide it right onto the wires. With this set up, I should be able to adjust the position of the mirror in a number of different axis, which is good, because I think putting this at the focal point and directing light onto the fiber bundle in the most efficient way is going to be a chore.

Sunday, April 13, 2008

Hitting the Fiber Jackpot

Best weekend ever (for light pipe building): I went to the ACCRC where James, the guy who runs the place, had 250 feet of fiber, dumped at his warehouse from a trade show. It was previously used to transmit optical light, not infrared telecom light, which makes it ideal for a fiber light pipe. He gave it to me. Amazing. The thing is, in order to get enough fiber, I was looking at spending more than $250 at vendors I found online. This dramatically reduces the project cost and puts discarded fiber to good use.

The other amazing thing that made this weekend great was that I got together with my friend Dan, who will be joining me at the fair. He had drawn up some sketches of a stand for the dish. This was going to be my biggest challenge because I'm not too experienced with bandsaws, routers, bearings and motors. Lucky for me, Dan loves this stuff. His design gives the dish motion in two axes. Also, he has a plan to use a motor and some disembodied wheels from a remote control car so that we can move the dish remotely. This'll be awesome for the display at the fair.

Monday, March 31, 2008

Giant head made of computer parts at the ACCRC

Here's a 20-second video of a 9-foot tall head (skull?) made out of computer parts. It can be found at the Alameda County Computer Resource Center, a non-profit that accepts electronic junk and either refurbishes it, or, like yesterday (when the Makers were there), lets people pick through it.

Video: Me with fiber and green laser pointer


Sunday, March 30, 2008

Friday, March 28, 2008

Coming soon: first video of fiber+panels

The parabolic reflector hasn't arrived in the mail yet, but I did get five feet of fiber from, just to play around with. I got the cheapest kind, ($0.74/foot), but man is it small. It's essentially a bundle of 8 0.75 mm fibers. Check it out. It makes me wonder how many fibers I'll need to get sufficient light into each panel. It gets me thinking about the placement of the fibers on the panel. It makes me think that I'll need to spend more money and get bigger fibers. I'm eyeing another site, called that might have better deals. Hrm, on closer inspection, it looks like it has better deals in some cases but not others.

Okay! This weekend I'll play around to see what works. I'll post video too.

Big Weekend + Collaborators

This weekend is going to be important. First, on Saturday I'll explore TAP Plastics, the place in San Francisco where I hope to get all of my acrylic panel needs (panels, cutting of aforementioned panels, scraps, advice). They also might know a thing or two about optical fibers. We shall see. Second, I'm going to the Maker Meetup at the ACCRC, the computer recycling center in Berkeley run by a Mr. James Burgett. Oh, man, it looks awesome! Maybe I can find some cool stuff. Motors? Check.

From James' blog:

We will provide in varying amounts and conditions. Monitors,flat panels,big led displays,a bart display,a cop light bar,boxes of walkie talkies in various states of repair,notebooks (parts machines, don't ask for working) motors from very small to forklift scale, ac and dc, fans.tripods,big freaking speakers,5 pallets of new music cd's,43 dissasembled electric scooters,wheel chairs,batteries,radio control equipment,electronic doodads,etc (we covet the powered unmentionables.)

I am so bringing a video camera.

And now some truly great news: the people I talk to seem pretty excited about the light pipe, and I now have a few folks who've offered to help. Jill will be with me for both days of the Maker Faire to help me set up and tear down and explain how awesome fiber optics are and how great it will be to finally have sunlight in our dark, dreary living room. What fun!

Also, I met a guy named Dan, from Berkeley, who knows a thing or two about engineering, collecting light, building parabolic reflector stands. That sort of thing. My old pal Todd from grad school is offering advice from a distance, specifically about the sun tracking stuff.

Anyone else who has ideas or wants to help, please let me know! It's totally super fun to do a collaborative project thing, especially when it involves motors and parabolic reflectors and optical fibers and living room illumination!

James Burgett of the ACCRC holding an EPA award in 2006

Tuesday, March 18, 2008

Project Description

Submitted to the Maker Faire:

I’m building a modified light pipe using a sun-tracking parabolic reflector and mounted mirror that focuses light into optical fibers. These fibers will be coupled to 1/4”-thick acrylic pane. Light is released from an acrylic pane--effectively a waveguide--via scratches on the surface.

Now, in more than 50 words...

The problem is this: the living room in my San Francisco doesn't get much sunlight due to one window being completely blocked by the neighboring building, and the other window being mostly occluded. At sometime near noon, a shaft of light beams through the partially occluded window, only to vanish 20 minutes later.

My plan is to mount the reflector on the roof of the apartment so that it can track sun all day. It will focus light into about 40 feet of fiber--which actually consists of 8 bundled fibers-- that I will pipe into my living room the same way I do with the cable coax. Once the bundle is in the living room, I'll separate the smaller fiber lines and individually connect them to the acrylic panes, which will mounted on the living room wall. The panes will have scratches on the surface so light scatters out. Hopefully this will brighten the living room during the day!