A solar clock that isn’t a sundial

Hack a Day’s very own [Jack Buffington] is throwing his hat into the ring for the Buildlounge laser cutter giveaway with his solar clock that isn’t a sundial.

The theory behind [Jack]‘s clock is pretty simple. The light from the sun will be captured by a camera obscura/pinhole camera. The sun’s rays shine on dozens of optical fibers that lead indoors and up to the clock. These glass fibers go to pinholes in the face of the clock which light up, showing the time.

[Jack] already cut out the face of the clock on his (awesome) home-made CNC router. He hasn’t gotten around to cutting out the mechanics of the clock face so the clock can be adjusted throughout the year. We’re okay with that, because we’re really not ready to see [Jack] fiddle with his gnomon. At least before [Jack] gets his hand on the Buildlounge laser.

The next major hurdle of the build is the solar collector that collects light into different optical fibers. That’s going to involve a lot of math using the equatorial coordinate system. Help is available, though.

Check out [Jack] cutting the clock face on his router after the break.

15 thoughts on “A solar clock that isn’t a sundial

    1. What’s your issue with WIP (work in progress) projects? I find it interesting to see the steps taken to get there, and in some cases imagining how I’d complete the project.

      1. i find it to be a waste of time as you can always go back and look at the process when its done and its not even a hack yet … just a milled peace of metal

    2. I like seeing the work in progress posts. One day we might find one that would be a nice project, but would languish without encouragement and support from the community.

    3. It might never be finished. And I find the work interesting none the less. Perhaps I can finish it? or it’ll inspire me to try too.

  1. Wow… fxcking youtube… I just went from watching someone start working on a project building a clock to spending about an hour watching interviews with serial killers. How does that even happen!?

  2. Wait, I’m confused…..If it relies on being in the correct orientation to give correct time, then it is a sundial, isn’t it? If I read correctly, it redirects the sun’s beams to illuminate the face.

    Still cool though! gotta love fiber optics!

  3. Well, just read here: http://blog.robotbrigade.com/?p=41
    The clock’s face shown in the photo has nothing to do with collecting or reflecting sun rays. It’s rather like this:

    1) sunbeams enter a box through a small pinhole that makes it actually a camera obscura. The shape of the sun moves along a path inside the box. As the camera obscura flips the image like a lens, the “hot spot” inside the box is far left if the sun shines from far right
    2) on the backside wall of the box where the sunbeams arrive, they are picked up by glass fibers along this path the sun walks through over the day
    3) Say, far right is equal to 6:00 in the morning, then the fibers from far right on the box backside wall go to the 6-hours pinhole in the clock face
    4) this illuminates only the 6-hours pinhole in the clock face, not any of the others – well, some of the sunlight may spread to the neighbor 5-hours and 7-hours fibers because eventually that depends on the clearness of the sun’s shape – if it is hazy outside, the sun won’t create an exact spot in the camera obscura but rather a blurry circle

    It’s a cool idea. As glass fibers can be pretty long without too much loss, the clock face can be considerably far away from the collector box.
    Plus, there is still potential for Arduino integration. If there is no sunlight or it is too clouded for the sun to come through, microcontrolled LEDs might kick in as light sources ;o)

    And even though it is unfinished, it shows a whole lot of creativity. Not all hacks require a power supply of some sort.

    1. Or the Arduino could collect the position of the spot through a bunch of photoresistors or, better an old webcam, use ephemerides to convert the position of the sun to time depending on the date and serve it as an NTP server using an ethernet or better a Wi-Fi shield?
      All this with PoE of course.

      Hmmm…

      :-)

  4. Nice idea, hope it works as planned. But I think the light indicating the early morning,and late after noon time will be pretty dim if it works at all, with a single aperture, that I assume will work best a mid day. Maybe multiple apertures to track the sun so the indicator at the correct time is the brightest? I seen where another commenter wants you to use an arduino,just use an arduino to control the position of the aperture. :) Have the clock on the right building during a solar eclipse, you have a means to view the eclipse indoors,far out.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s