Mar 312016

Recently my friend Roger Knights sent me a link to his review of a product called “cord cuffs” on the website Cool Tools. This reminded me that I had also purchased some plastic “cord cuffs” some years ago, but I never found a use for them. Instead I’d come up with my own method of securing extension cords.

First off, most people wrap their extension cords incorrectly. The proper way to gather line is NOT to simply gather it together in overlapping loops. This TWISTS the line. A quick Google search of the terms “how to coil a rope” yields a number of valid ways to coil a rope. But since an extension cord is almost certainly going to be less supple than any rope, I’ve chosen a very basic way of coiling for myself, which is seen here. Simply alternate loops with half-hitches. A loop imparts a small twist in one direction, while the half hitch imparts a similar small twist, but in the other direction, thus balancing out the twists in the line. The final bundle is roughly circular, which avoids bending or kinking the copper conductors inside. An excellent written account coupled with a video on the Lifehacker website demonstrates this method.

Overview Crop

First create a closed loop with a short length of strong line such as parachute cord. Instead of attaching the free ends with a knot, I’ve chosen to use an electrical butt connector, and to cover it with heat shrink tubing. A knot would be excessively bulbous in this situation. A butt connector is undoubtedly less strong than a knot, but in this situation the line is not supporting much weight.

Close Up One

I’ve chosen to attach the loop near the male end of the cord, but it would work just as well at the female end. Since the male end is either plugged into a receptacle, or attached to another extension cord, attachment at the male end avoids any interference with the device that the extension cord is plugged into. The loop is affixed to the extension cord with two small zip ties, which also help to offset the intrinsic weakness of the butt connector.

Close Up Two

An advantage of this method is that the final coiled extension cord can be suspended from a small peg or hook.

Suspended Cord

 Posted by on 03/31/2016 Art, Science Tagged with:  Comments Off on Extension Cord Storage
Jan 282012

You have probably heard of wallets made of duct tape. They certainly work well, but there are a few disadvantages. One is that many brands of duct tape are cheap, and deteriorate in short order. The silver facing wears away leaving reinforcing fibers that fray. The adhesive is sometimes not very tenacious and leaves a thick, sticky surface if the tape is pulled away.

I made my own duct tape wallets starting in the summer of 1992. In about 2003 I started making wallets out of a kind of tape that I believe is superior. It goes by several names, but one common name is “house wrap tape.” It’s often sold in conjunction with Tyvek house wrap. The tape is made of polypropylene, and is very strong for its weight. Unlike duct tape it’s isotropic, meaning that it’s the same in all directions, and won’t tear or fray. The adhesive is a very aggressive acrylic, which is needed to stick to the slick surfaces of Tyvek house wrap.

DuPont’s Tyvek house wrap tape is by far the most common brand of this kind of tape. The only downside is esthetic; it has “Tyvek” printed in large letters all along the tape. It’s possible to buy plain colored house wrap tape; I bought the roll I’m using in this essay online. I once had several rolls of Owens Corning house wrap tape which came in pink and had no text. Additional information about these tapes can be found here.

To create a house wrap wallet, we need to know how fancy we want to go. My wallets are simply the main currency pouch plus two smaller card pouches. These instructions are for this style.

To start off we will create the two smaller card pouches. Unroll a 7” or 8” length of tape and place it sticky side up on your table. Unroll a similar length and overlap it about half way lengthwise. Cover the remaining section of sticky-side-up tape with another fresh piece. The fresh piece does not need to overlap the first. Turn the three pieces over and overlap the sticky side up section lengthwise. Repeat this process until you have a panel of tape about 7” wide by about 5” tall.

A typical plastic card like a driver’s license or credit card is about 2 & 1/8” tall by 3 & 3/8” wide. Our card envelopes will be about 2” tall to allow the tops of the cards to peak out and be easily grabbed. Mark the long edge of your panel with a straight line and cut it straight. A Sharpie permanent marker works well for drawing on polypropylene. To minimize edges that can come apart or expose adhesive, overlap a fresh piece of tape on this straight edge and roll it over on the other side to secure it.

You may notice the acrylic adhesive binding to the blades of the scissors you are using. One way to remove this is with WD-40, which also lubricates the revolute joint. Be careful when wiping scissors blades, as they can be quite sharp.

Fold the panel with the cards you intend to carry inside. Allow the tops of the cards to peek over the top. My card envelope dimensions are just about 4” or perhaps 4 & 1/8”.

If you look carefully, you might be able to see that the edges of this panel are squared and cut, and the edges covered with an overlapping length of tape.

Each card pouch panel is about 3 & 3/8” wide. Fold one panel in half and tape one edge together. Place your cards inside the pouch and tape the other side edge.

Once the proper height is determined, cut the panel into two sections.

Don’t worry if you are taping over a gap, as we will correct this in a latter step. Make sure to align the tops of the two envelope sides as you create this seal. Since the adhesive is on the inside, it creates an unfortunate situation, since the adhesive will tend to stick to the cards. We remedy this by everting the card pouches. Remove the cards and turn the pouches inside out. To fully evert the corners, use a single plastic card to push the envelope from the inside out. Eventually it should fully evert. Reinforce the sides with extra tape.

Now the two card pouches are joined side by side. Notice there is a gap of about ¼” between the two pouches. This is to allow them to fold together without binding along the crease.

A new panel is created for the main currency envelope. An American bill is about 2 & 5/8” by 6 & 1/8”. The width and height of the currency envelope will need to be greater than these dimensions. The width should match the width of the joined card pouches.

In this case the currency envelope is 7 & 5/16” wide. As with the card envelopes, cut the panel to the correct width then fold down the middle to create the crease. The height in this case is 3” so the panel height before folding would be 6”. Tape the edges, evert the envelope, and seal with additional tape.

Join the currency envelope to the card pouches along the sides and bottom. You will see a gap at the top of the card pouches that should be taped down. Slip a section of tape inside each card pouch and adhere it to the card pouch and the envelope pouch. Add additional reinforcement along the sides and bottom of the wallet.

There you go! My previous polypropylene wallet lasted about 5 years, and was much more elegant than a duct tape or gaffer tape wallet. I call this model the “Big Red One.” Good luck!

 Posted by on 01/28/2012 Art Comments Off on Creating a Polypropylene Wallet
Aug 132011

From time to time I receive requests from sideshow performers for me to build them a pump for their own gavage acts. I am not in the business of manufacturing such devices. You will have to find a machinist to fabricate this for you, or else have the tools and skills to do it yourself. I can only describe what I did to build my own. I did not have a lathe, only a drill press. You will almost certainly have better results if you use a lathe instead of a drill press. The dimensions I am giving work for a particular sized barrel; I just happened to pick up an acrylic cylinder as scrap of this size. If you start with a different sized cylinder none of the following dimensions will work, and you will have to modify everything.

I built two pumps back in the early 1990s when I invented this stunt. One was stolen in Copenhagen, and the other remains with me. Both were essentially the same size. I started off with a clear acrylic cylinder 10” in length, 4.485” OD, and 3.975” ID. Clearly this is a 4” ID nominal tube. From there I used a drill press to machine an end cap, again out of clear acrylic, to seal one end. This was the most labor-intensive part of the fabrication, as I had to machine it to a few thousandths of an inch over the ID of the barrel. If you plan to do this yourself, you will need a reliable dial or digital caliper. The end cap on my unit was .675” thick, again made of clear acrylic. When your end cap almost fits into the barrel, use a heat gun to soften the end of the barrel. I chose not to use adhesives to secure the end cap into the barrel, but perhaps one could; I honestly don’t know what would work best. Both of my pumps held liquid under pressure for years with no leakage or malfunctions. You will notice the presence of “crazing” on the end of my barrel; this is a common phenomenon with all many plastics under stress. I suppose one could further secure the end cap with a metal band, or drill screws or pins into the plastic, but I didn’t need to.

From there a brass plumbing fitting was installed in the end cap. This was threaded with pipe thread, so you will need a pipe tap that corresponds to the threads on the fitting you are are using. The fitting needs to dimensionally match the tubing you will be using. Since I used tubing whose ID was 3/16” you will need to choose a metal fitting that will allow that size of tubing to slide over the hose barb. The tubing is elastic, and will expand a bit to fit over a hose barb. I sealed the junction of the threaded hose barb and the acrylic end cap with plumber’s epoxy on the outside of the unit. Black vinyl tape was wrapped around the junction of the hose barb and tubing to provide strain relief. If I were doing this today I would probably use silicone tape instead.

The plunger of the pump is a series of acrylic disks which hold the O-rings in place on a stainless steel rod. The opposite end of the rod is a plastic T-handle. There are two sizes of disks, which are sized to allow just a portion of the O-ring to be exposed to the inner surface of the pump. Again, the dimensions I’m providing are for a barrel whose nominal ID is 4”. The inner disk is 3.550” across and .229” thick. The thickness is nominally ¼”. The larger disk is 3.917” across and the same thickness. I started out using 4 O-rings, but later on found I could get by with just 3. For a 3 O-ring stack you will need 4 large disks and 3 small disks. I chose to tap the centers of these disks to match the threads on the stainless steel rod, which in this case was 3/8” coarse threads.

Believe it or not I was initially unable to find O-rings that fit this application! I fabricated my own using over-sized O-rings and Loctite Prism cyanoacrylate (superglue) #11. The ends must be diagonally tapered at the butt joint. I’m quite confident that anyone building a gavage pump in the 21st century should be able to find 4” OD O-rings commercially. Obviously the thickness of the O-rings needs to match the thickness of the plunger spacer disks. The ones I used were .240” thick.

The stainless steel rod I used was 14” by 3/8”. Both ends were tapped for 3/8” coarse threads. The plunger disk end was tapped 3” and the T-handle end was tapped 2 & ¼” or just a tad longer than the T-handle is thick. I ground a couple of flat spots on the rod to allow the rod to be chucked into a vice while I tapped the rod. This will also allow the use of a crescent wrench to hold the rod while assembling and disassembling the plunger handle. While I used galvanized washers, I wouldn’t recommend it for anyone building one today. I would stick with all stainless steel washers and nuts. On the plunger disk end I used an ordinary stainless steel nut in the middle, with nylon locking nuts at the end. If I was building this today, I would use nylon locking nuts at all four points; two on the plunger end and two on the T-handle end. Use a washer under all four nuts. Besides a crescent wrench, you will need a socket wrench to access and rotate the nut on the outside end of the T-handle.

The T-handle I used was also plastic, in this case a section of polyethylene whose dimensions are 6” by 1& ¾”. The center hole was counter sunk to allow the nuts and washers to fit inside elegantly and to prevent the center rod from biting into the flesh of the gavage assistant. In my case the countersink was a 1” wide bore.

The tubing I used was Tygon R-1000, 5/16” OD and 3/16” ID. The part number I used was AAU00012. As of this writing, this part number is still current. The tubing length I used was 7’. The end was tapered, and a series of cuts were made into the sides near the end to facilitate fluid flow. These cuts were made with a diagonal wire cutter.

I used PAM brand non-stick spray to lubricate the plunger when performing my act.

 Posted by on 08/13/2011 Art, Personal History Comments Off on Building a Pump for the “Tube” Act
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