Apr 272011

Most consumer grade laser pointers come with a momentary switch. Some people might want to have a conventional on/off switch instead, say for photography. Here’s a quick and easy modification that requires no switch replacement or re-wiring.

Start by wrapping tape around the barrel of the pointer right next to the button switch. Build up the tape to a height of about one millimeter. Don’t wrap with a lot of tension, or you may experience the dreaded “tape creep.” Wrap two bands which will act as retainers to keep the modified switch from sliding up or down the barrel.

Find a zip tie that’s roughly the same width as the momentary switch button. The zip tie I’m using is about 5mm wide. If you use a wider zip tie, your tape retaining bands will have to be moved aside to the same width as the zip tie. Encircle the zip tie over the barrel in between the tape retaining bands. Contract the zip tie until you come near the button, positioning the zip tie locking lug over the button. As the zip tie contracts, it will form a teardrop shape, with the locking lug forming the pointed end. Carefully contract the ratchets of the zip tie until the lug almost touches the button but does not turn it on. This is the new “off” position, and should look like this:

Rotating the tie will remove the slack under the locking lug and depress the momentary switch. This is the new “on” position, and looks like this:

Cut off the excess “tail” of the zip tie, and you now have a reasonably elegant on/off switch.

I was able to use my modified laser to capture this image, which is a green glass sculpture in Seward Park here in Seattle:

 Posted by on 04/27/2011 Art, Science Comments Off on Laser Pointer Switch Modification
Apr 092011

Somewhere in the late 1980’s I learned about a forensic phenomenon known as “powder tattooing” from reading Vincent DiMaio’s classic text Gunshot Wounds. In some cases it’s possible to estimate how close the muzzle of a firearm was to a wound if unburned propellant residue is found embedded into the tissues surrounding the wound. I read DiMaio’s book around the time I read the now-classic ReSearch book Modern Primitives. It began to dawn on me that traditional tattooing is actually somewhat limited in the tools it uses. Very simply liquid pigments are pushed into the dermis using either a hand-held tool or with a reciprocating electromechanical device. A single needle can be used, or a group of needles.

As the Modern Primitive subculture progressed, people began to push the envelope in all sorts of ways, mostly with piercings and implants. Tattooing has certainly become more common, yet the technology hasn’t really progressed since the tattoo gun was invented by Thomas Edison. I should like to make a modest proposal, namely that it’s time to push the envelope and embark on a new kind of body modification. This would be powder tattooing as art.

First off, you can’t actually shoot your clients with real bullets, as this tends to diminish repeat business. Instead of using lead bullets, I propose that powdered pigments be used. These pigments would be fired from real firearms, at ranges close to the subject’s skin in order to push the pigments into the dermis. Modern metallic cartridges could be used, although the specialized rounds would have to be hand loaded. Perhaps the pigments would need to be held together with an adhesive binder of some kind, in order for the projectile to be held securely in the cartridge. The technology of tablet manufacturing is well established, and could be adapted to creating pigment projectiles.

In powder tattooing, a whole range of variables opens up which includes the caliber of firearm, the length of the barrel, the distance of the muzzle to the skin, the exact composition of the pigment, the angle of the barrel to the skin, and the brand and mass of the propellant charge. The skin that is not to be tattooed would be covered with a metallic or Kevlar mask.

Imagine you’re an outlaw biker, a real one-percenter, and you want a nice little rose on your ankle. You start off by taping a mask that defines the outline of the rose to your skin. We first apply black pigment, so colored areas are blocked off with adhesive-backed masks. You and the “Shootist” put in earplugs and don eye protection. Safety first! The shootist starts off with a .357 Magnum with a 6” barrel. The “round” is plain black tattoo ink propelled with 4 grains of Hercules powder. The shootist measures the distance to the target, and fires. The distribution of powder will tend to concentrate in the center, so touch-ups would need to be applied to the perimeter. Additional masks could be applied to the center so the periphery is exposed.

Now for the green leaves and the red petals. A new mask is applied that isolates the green leaves. Note that this process is analogous to Japanese woodblock printing in that an entire color is applied at one time. Undoubtedly hipsters will get The Great Wave off Kanagawa ASAP… Since the green is small and isolated, the shootist shifts to a Ruger MKII in .22 caliber. This is a semiautomatic handgun, so the bolt will probably have to be hand-cycled, as we are using “light loads.” This time the shootist moves in very close, perhaps within in inch. The shootist keeps the colors consistent, and goes with Green Dot propellant. Bang! Now we have some sweet leaves…

Now for the tricky part, the red petals. Again, a third mask is applied, which isolates the petals. This element occupies more area than the leaves, so we want greater dispersion. A Charter Arms .44 Bulldog is chosen for its large caliber and short barrel. 5 grains of Red Dot blasts the persimmon pigment into the dermis in a “one shot stop.” No need to double tap this baby…

Though entire patches of color are applied at one time as in Japanese woodblock printing, art aficionados will probably notice the results have a somewhat “stippled” appearance. This results in a more pointillist style. Perhaps in the future, a re-make of Ferris Bueller’s Day Off will be made which features a scene of an entranced teenager starting at a man’s bare back, stippled in the style of Seurat…

As with all things underground eventually the mainstream co-opts the cutting edge, and what was once outre’ becomes ordinary. Some of the old school Master Blasters will sell out, and soon we will see powder tats on the latest Disney pop stars. But the Jonas Brothers of the future won’t have the balls to actually be shot, so this is where pneumatic vaccination guns come in. Since smallpox was eradicated in the human population in 1979, pneumatic vaccine guns have become museum relics. Some enterprising Ed Hardy type will figure out that these can be “re-purposed” and used to inject pigment rather than vaccine. Sure, we’ll have a “crier’s corner” for those who can’t cut it, but by and large a pigment “inoculation” should be less painful than getting “the shot.”

 Posted by on 04/09/2011 Art Comments Off on Powder Tattooing
Apr 012011

In my entire lifetime I’ve been locked out of my house or vehicle fewer times than the fingers on one hand. I always keep my keys in a pouch in my front pants pocket. Even then, modern vehicles will automatically lock the door if the door is shut with the locking mechanism on.

Years ago, I drove a 1987 Dodge Daytona Pacifica. I was shocked to find out how easy it was to “slim jim” my way into the car, or most cars for that matter. At the time, I was particularly concerned about it being stolen, mostly because it was a relatively new car. I was good about always checking that I had my keys in my hand or pocket as I closed the door, but no one is perfect. I fabricated a very simple slim jim from a hacksaw blade and learned how to open my own car door. I hid it in the plastic bumper of my car.

I had to use it on one occasion, and a woman actually stopped and asked me what I was doing. Evidently she believed my true story that I locked my keys in the car, and she didn’t call the police. After I sold my Daytona, I owned a series of 1965 Fords, which required one to lock the door from the outside. In my opinion, this is the way that all cars should be built, but obviously my opinion carries no weight with automotive designers.

Several years ago I bought a 1977 Ford F-250. By 1977, Ford was making their vehicles in the new style, in which one is not required to lock the door from the outside. For a long time I rationalized that I simply wouldn’t need a slim jim or extra hidden key, as my discipline was so good. Well, no one is perfect, and eventually I screwed up. Thankfully it was when I arrived at work. This was when I was working in the maintenance department of a steel fabrication facility. This business employed a lot of ex-cons, and thankfully one of my co-workers was proficient with a slim jim. He opened the door of my truck and delivered my keys to me. I think he’d taken a couple of falls for burglary, but I never asked him. He was one of the nicer ex-cons I worked with…

I knew deep down that I would have to come to terms with the lockout issue, and I finally took care of it tonight. For years, I’ve kept useful tools in belt pouches. Here’s a photograph of the pouches on the left side of my belt:

On the far left is a leather pouch for the Core model full size Leatherman tool. In my opinion, the latest iterations of the Leatherman tool are some of the best designed hand tools ever created. On the far left is a pouch for a butane lighter. In the middle is a leather basketweave pouch intended for a mini-mag flashlight. I keep a mini-mag, but on my right side. Instead of a flashlight I keep a copper tube, which has a friction fit cap. I bought it years ago in the plumbing department of a hardware store. I believe it’s supposed to be used as a water hammer preventative. As it just so happens, the copper tube fits inside the flashlight holster just about perfectly:

Amazingly enough, I didn’t even have to cut the tube to length to allow it to fit inside the holster!

Until tonight, I’d been using the tube just to hold a ball point pen. But this was unnecessary, as the Carhartt jeans I wear have small side pockets that are perfect for pens. So tonight I finally got around to doing what I should have done years ago; put some extra keys in a belt pouch. I had to sand down a house door key and a door-ignition key so they would fit inside the tube. I cut a piece of plastic to act as median barrier so the keys wouldn’t rub against each other and rattle around in the copper tube. I made a lanyard loop out of 80 pound test braided Dacron fishing line:

Of course, this is all well and good for keys locked in a truck, but won’t save me if I run out of the house in my casual wear, which is usually a sweatshirt and Nylon running shorts. If a rabid raccoon got in my house I might just make a dash for the door, in which case I’m screwed!

 Posted by on 04/01/2011 Personal History Comments Off on Lockout!