Starfield Coffee Table

Coffee Tables Are Boring

In order to fix this insidious (and totally contrived) problem, I decided to make mine significantly more interesting by adding about 400 feet of fiber optic filament, some stepper motors, and an Arduino controller.

The first step was to drill all the holes (over 350 of them). It seems somewhat easy to put random holes in a table, however, it turned out to be surprisingly difficult. My brain favors order and consistency far too much and I found that I was filling open spaces and attempting to distribute all of the holes evenly.  I wanted the pattern to be truly random so I threw hundreds of BBs on the table and marked where each one was before drilling. It was a lot of work and made a huge mess, but it did make a good pattern.

These actually were un-hydrated "Orbs" (super-absorbent, polyacrylamide polymers), but that is irrelevant.

These actually were un-hydrated “Orbs“, but I suppose that is irrelevant.

The holes were drilled, the fiber was inserted and glued, and the loose ends were bundled together and cut flush with each other. This took a LOT longer than you might think because I did not want to just grab the filaments at once and tie them together. This would cause the color changes to sweep across the table in a linear motion. I wanted the color to appear from all over the table at once so the transitions did not look mechanical. I did this by grabbing smaller bundles of 8 or so filaments together (2 from each quadrant on the back of the table) and zip-tying them together. This way, when I put the small groups together in the final bundle, it was unlikely that any given filament in the bundle (where the light is coming in) was adjacent to a ‘near by’ filament on the table surface. (probably sounds excessive, but it was worth it in the end)

Bundling the filaments.

The filaments from each quadrant (green zip-ties) were joined and added to the main bundle (orange zip-ties).

When it was done, it looked like this…Underside of table

Here are some long-exposure pictures of the table being lit-up with a laser (it is easier to see the filaments this way – plus it is just way-cool to see)

Using a laser to light up the filaments.

Using a laser to light up the filaments.

And here is the exact same thing with an ultraviolet laser… (just too cool to not show)

UV laser front and back

Next two motors were installed: one controlled a color wheel and the other controlled an interference pattern to create a twinkling effect. The motors come with the ULN2003 driver boards which were controlled with an Arduino Uno.

The motors will spin 2 acrylic disks in front of the LED for color and interference.

The motors will spin 2 acrylic disks in front of the LED for color and interference.

I used SketchUp to design a mounting bracket for the circuit boards. This made it easy to mount all 3 of them anywhere without putting strain the wiring or fibers.

Printed circuit board mount.

Printed circuit board mount.

Here is the final circuit mounted on the bracket:

A prototype board is sitting on top of the Arduino.

A prototype board is sitting on top of the Arduino. The red blocks off to the right are used to hold fiber optic lines directly over the existing LEDs on the motor driver boards.

I wanted to control the speed and direction of the motors so I could see what patterns and colors looked the best (for future projects) so I built a control panel that extends from the bottom of the table. In order to stop the motors, a pause button was added for each that calls an interrupt on the Arduino.

The motor driver boards each have 4 red lights on them to indicate the speed and direction of the motor. They are useful to tell what is going on under there, but I didn’t want them blinking away and lighting up the underside of the table. Instead of removing them, I covered them up (with a printed housing) and ran fiber optic filament back to the control panel so they were still visible but only as tiny dots.

The little white dots are the fibers going back to the motor control LEDs.

The little white dots are the fibers going back to the motor control LEDs.

Control Panel and Circuit Board.

Control Panel and Circuit Board.

Here what the whole thing looks like mounted under the table…

Under Table Mount

Here is a video showing a flashlight lighting up the surface filaments:

Finally, here is a video of it in action…

I think it significantly reduced the feeling of “blah” that the table seemed to convey before the upgrade.

As an added bonus, I can set the color to “grass”, “lava”, or “water” when my daughter is playing on it with her action figures!

Dan.

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Cedar crystals

I expected to find more on this topic on the world wide spiderweb, but since few have posted pics of this phenomenon I thought it would be good to do so.  Maybe carpenters who work with cedar see it all the time but it was interesting to me.

In a nutshell, my wife asked if I would cut some some disks from a large red cedar branch that broke off a nearby tree. I used a miter saw (we call it a chop saw ’round these parts) to cut a bunch of disks –about 3″ diameter, 1/4″ thick  drink coasters basically.

The cedar aroma was great and we left one wafer sitting around on the pantry shelf. A couple of days later I was back in the pantry searching for some type of food item that would require zero forethought or preparation time, and glancing at the cedar disk I noticed a frosty, sparkly something on its surface.

Looking closely, the red heartwood center of the wooden disk had grown very fine crystalline whiskers, some around 1 to 3mm long (yes I’ll switch to metric on you like that when the micron range becomes ponderable). The little clear needles seem to orient in various directions and extend out from the surface at different angles.

My quick and dirty “solubility test” consisted of a drop of water in one area and a drop of rubbing alcohol in another.  The crystals were unaffected by the water and dissolved nearly instantly in the 70% isopropyl alcohol.  Oh, and the flame from a lighter vaporizes them pretty instantly also.

From what I can find, the substance is likely crystallized libocedrol, a component of the aromatic oils found in the tree. The tree is Juniperus virginiana and I don’t know if any particular conditions like temperature, moisture content, etc. affect the crystal formation or if the tree just had a lot of the compound available to release. Nor have I researched what other trees may have it or if it’s common to see. I do know the internet needed a few more pictures of it so here are a few from my little USB microscope.

 

-GRJ

 

 

 

 

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