Archive for the ‘Crafts’ Category

Pseudoscope

Tuesday, July 28th, 2009

Next up on the Calvacade of Learning Experiences!  (I thought “Calvacade of Failure” had a nice ring to it, but… optimism, please.)

A pseudoscope is a device that flips the line of sight of your eyes; that is, the line of sight of your right eye is transposed with that of your left eye, and vice versa.  The purpose of pseudoscopes was to help figure out how people process depth information.  Supposedly, the actual visual input being reconciled with the expected input results in some convex shapes being seen as concave, flipped depth values for objects in close proximity, and other oddities.

Unfortunately, it didn’t work for me.

Rather than purchase a $750 pseudoscope, I followed the instructions here, which result in a rather more economical $10 pseudoscope.

Pseudoscope Parts

Pseudoscope Parts

The above picture shows the parts I started with.  Nitpickily observant readers will note that the mirrors are too small for the instructions given at the link.  This is because these were the closest size available at the store.  As I discovered, optical devices require a bit more precision than “whatever they had at the store”, and so I later purchased the correctly sized mirrors online.  Financially observant readers will now note that this device cost rather more than the expected $10.

A bit of measuring and assembly later:

Pseudoscope

Pseudoscope

In the picture above, your eyes should be placed at middle left, and the field of view extends to the right.  The logic behind the mirror placement is evident.

As I said, this doesn’t work for me.  I spent an hour or so focussing it, rather like a coincidence rangefinder, moving the two images together, and then looking at different objects under different conditions.  Inside, outside, dark, or light, with a long or short focal distance, my brain resolutely refused to be tricked.  The only oddity I noticed was the path distance added by the pseudoscope made me misjudge how close nearby objects were.

I can think of a few reasons why this didn’t work for me.  I am reasonably sure I got the focus right, so this probably is not it.  The first possibility is that I needed still larger mirrors to completely cover my field of view, and that there was enough reference information left unreflected by the mirrors that my brain was not misled.  The other possibility is that it did not work for me because I am about 70% left eye dominant, which both mucks up the positioning of the mirrors and puts another reference point into the equation that my brain was processing.  This too may have been enough information to prevent the illusion for taking effect.

In any event, I’ve spent enough time on it, and so it will go on the shelf of interesting ideas that didn’t pan out.

LED jar

Friday, June 19th, 2009

I saw the Sunjar at http://charlesandmarie.com/, purveyors of interesting stuff, last week, and thought it looked like a pleasing nightlight.  I don’t feel that I need a nightlight, but I happened to notice that the empty jar from my hair, erm, product looked similar to the Sunjar’s container.  When I saw a spare electronic switch on my desk, I figured that I had the makings of a minor diversion on my hands.

parts-25

Step forward, Tresemme Smooth and Silky European Deep Smoothing Masque!  At $4.00 for a sizeable jar (alas, not quite large enough to qualify as a “jug”), this is the least expensive chemical of its consistency on the supermarket shelf.  The adjective to dollar ratio is also quite good.

Step 1: wash the jar.  While the fragrance of Vitamin H(?!)-fortified hair goop is not unpleasant, it is more suited to salons of the follicular type than the dining sort.  Oddly, the jar is double-walled, and some water got into the gap between walls when I washed it.  I had to flex the outer wall a bit to drain the water out.

Step 2: This jar has the additional advantage, for our purposes, of having the product information applied via sticker, rather than painted on.  One scientific application of pocket knife later, the large label is free, and the top label yields quickly to a fingernail.  I cleaned off the top with alcohol to get the glue residue off of the otherwise pleasingly gloss black plastic.

Step 3:  Drill a ~ 3/8″ hole in the center of the lid.  Finding the center is left as one of those irksome “exercises for the reader”.  I measured across mine a few times and marked several linear center points until they clustered.  There is probably a more elegant way to do this.  Note: don’t use a center punch; it will shatter the plastic.  In unrelated news, the lid to my currently in-use jar of hair gunk has a large swathe of packing tape across it.

Step 4:  Remove the threaded nut and lock washer from the switch.  There is a little nubbin at the top of the threads meant to restrain the lock washer.  This will be in the way later on, so cut it flush.  Do not look straight down at it as you do so, lest it bounce off of your face when it flies off.

switch-251

Step 5:  Twist the switch through the hole, leaving the button on the top of the lid, and then thread the lock washer and nut onto the switch threads from the other side, leaving it spark-plug like when viewed from below.

lid-25

Step 6:  Retrieve your electric gear bag from your car trunk, where you forgot it last night.  Wear your coat or you’ll catch a chill.

Step 7: Do some math.  You usually want a resistor in series with the LED (“throwies” notwithstanding).  The LED circuit formula to get the needed resistance is:
R = ((Battery Voltage) – (Voltage drop over LED))/(LED current spec)
The latter two terms are printed on the back of the box of LEDs.  Unfortunately for me, the box I got was an assortment, with a voltage range given.  It turns out that different color LEDs use different voltages.  Fortunately, this is usually predictable.  I looked up the value for yellow LEDs, since I wanted a yellow color.  I then did the math and then bought a “close enough” valued resistor.  Yellow LEDs with 2 AA batteries (3 volts) need about 45 ohms inline with them.  I got a 47 ohm resistor; since this resistor has +/- 5% confidence, I figured I was close enough.

Step 8: Figure out a way to hold your batteries.  I had a battery holder lying around, so I just used that.  They’re cheap enough, but you need to make sure to find one that will fit across the inside lid of the jar with the switch in the way.  Make sure to thread the bottom of the jar on when testing the size, since the male threads diminish the available space further.

Step 9:  Solder things.  In order: 2xAA positive battery holder terminal – switch – 2 yellow LEDs in parallel – 47 ohm resistor – negative terminal of battery holder.
Things to look out for here:

– LEDs have a positive leg (longer) and a negative leg.  Make sure to solder them in the correct order.
– You might want to use a length of wire in between components to ease the geometry a bit.
– Don’t lean your soldering iron against the jar lid.  It smells bad if you do so.

Step 10: Neaten up a bit.  I stuck the battery holder to the lid with some 3M double-sided sponge tape.  You can’t fasten it to the jar because then you can’t screw the lid on without breaking wires.

jar-circuit-251

Step 11: Try it out.  You might need to bend the LEDs around to get a better throw pattern.

lit-up-in-dark-25

This won’t replace a real Sunjar, since this looks cheaper, isn’t made as well, isn’t as bright, and isn’t solar powered.  Looks neat, though.

jar-251

The switch and LEDs here are from Radio Shack.

Switch: SPST Push-On-Off switch (275-1565)
LEDs: 276-1622 (assortment)

The Romance of Small Containers

Friday, May 29th, 2009

unstained box front view

(ed: Written in January 2009)
This may be another aspect of my unfortunate materialism, but I think that people (me) like small containers and packages out of proportion to their value.  Improbably small water bottles?  A few chocolates sold for much money in a small tin?  Tiny permanent marker?

Perhaps it is because small packages are cute, or that well-made small items attract consideration simply because they are stronger than their cheaper, less well-designed cousins.  Having an item (or experience) that is better than you first thought it would be is always pleasant, one of the minor happinesses of life.

Packaging matters, it seems.  However, I don’t own a manufacturing plant, and cannot hire a designer for my stationery box, or the bin I throw my pocket items into.

One of the quickest, cheapest projects I have done still makes me smile a bit.  Most big craft stores carry a line of small wooden boxes, ranging from the uselessly small up into the humidor sizes, though a cigar aficionado would likely advise you against using the latter to store cigars in.  They are called “trinket boxes” or the like.  They are made of cheap wood, machine cut, and are usually joined decently, though the hinges and latch are often indifferently fitted and of iffy quality.  They run between $4 and $12.  I’ve purchased a few of the plain (cheaper) ones, which look, well, like this:

unstained box ortho view

I should have put a ruler in the picture; it’s about 6″ long, and rather plain looking, no?
A paper towel, rubber glove, and $.40 worth of stain later:

small box stained ortho view

You want to know what is inside.  A gentleman’s pocketwatch?  A lady’s favorite day-to-day necklace?  A lucky Krugerrand?  A Brasher Dubloon?  (paging P. Marlowe…).
The cherry color here is Zar Cherry 116.  I removed the hinges and latch, and then I just rubbed on the stain with the paper towel, with no surface prep and no subsequent finishing.  The unsealed wood soaks up the stain, and the grain hides minor imperfections in the surface and gives an impression of patina.

As a note, I think I favor the results I got with Minwax Red Mahagony stain:

red-box

Wooden boxes benefit from looking at least a few years old.

Bronze powder ersatz

Friday, May 29th, 2009

(ed: written Jan 2009)

As I mentioned previously, I read George Grotz’s book The Furniture Doctor a while ago.  It is well-written and informative on many subjects having to do with furniture restoration, particularly the myriad of finishing options available.  Should you get a copy, I would suggest the updated edition published in the 1980s, and particularly commend your attention to the chapter about forging furniture, which provides an amusing glimpse into a world that I had not previously encountered.  (Step one: build armoire.  Step two: put armoire on windswept hill for one year.  Turn monthly to ensure even exposure.)

One of the types of finish that he discusses is the use of bronze powder over (usually) some sort of black paint.  You see this used to make images of fruit, vines, or as a sort of pinstriping.  I was once fascinated by a rocking chair at my grandmother’s house that had this treatment, but had forgotten entirely about it until reading about how it was done.  As one would suspect, you use stencils.  What I didn’t suspect was that you can, with delicacy of touch, “fade” the bronze color to the background black; you apply the powder with a little felt thimble worn over the finger, which naturally applies more powder at the beginning of a stroke than at the end.  You can then manipulate this technique to provide a three-dimensional effect to the pears you are stencilling onto your chair.

This is all a long-winded way of saying that I like the look of bronze striping on black, but am not terribly willing to spend lots of time laundering felt thimbles and mucking about with vials of bronze powder to get it.  While rummaging around in my “misc. supplies” drawer last week, I turned up a jar of gold Stencil Magic (R) Paint Creme that I purchased at a craft store some months ago, perhaps due to a half-remembered impulse to draw metallic fruit on my stationery box.

This Creme (?) is a viscous material that applies more like a soft wax than paint.  In addition to noting that “Labeling conforms to ASTM D-4236”, the top of the jar informs me that it is NONTOXIC, a claim I am reluctant to test, given the uncanny resemblance the material has to ground metal in a somewhat fragrant suspension.  (While I know that small amounts of some metals aren’t toxic, I am not reassured by the perhaps overly emphatic all-caps nature of the claim.)

Not having an appropriately expendable smooth black surface handy, I figured I would just try it out on an index card to get an idea of how it looks.  I am also unwilling to trust to my stencilling ability, an ability I last practiced in the second grade or thenabouts.

stencil

I drew a letter “R” in stylized script on an index card, and then cut it out with an X-Acto type knife.  (For those wondering, that is a Gerber Artifact, a curious pocket tool I received as a gift recently.)  To my suprise, I remembered to leave material connecting the outer stencil to the inner stencil covering the hole in the “R”.

pre bronze application

I taped the stencil card to a blank index card.  I then selected a piece of the finest paper towel I had lying around, for use as a brush.

When the Stencil Magic people inform you that a “skin” will form on the surface of the Creme, they aren’t kidding.  I gouged a hole in it, and then began wiping the creme onto the card through the hole in the stencil.  It has a pleasing consistency, though you need to use more of it than I expected to get a solid coat.  Once done, I removed the stencil from the final card.

post bronze application

Results: more experimentation needed.
1)  As is obvious from the picture above, I need to immobilize the small pieces of the stencil better.  The feathering of lines surrounding the hole in the “R” show that this part of the stencil moved despite my efforts to hold it steady.
2)  A brush might work better to get an even application, and is in fact what you are supposed to use for this.  I’ll probably try a cheap flux brush next.
3)  This stuff doesn’t fade well, since it seems to dry patchily if you don’t use enough of it.  It does look good in the places where I put enough on, though, with crisp edges.  It would probably be good for pinstriping or other solid designs.  I would want to clearcoat it to protect it, though, as one would do with real bronze powder.