Open MAKE: Tools – Licking Machines, Conductive Ink, and Lost Gold

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Open MAKE: Tools – Licking Machines, Conductive Ink, and Lost Gold
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Among the things I enjoyed at last Saturday’s Open MAKE: Tools at the Exploratorium is Benjamin Cowden’s “Eating My Cake and Having It Too,” an art mechanism that lets you use levers to operate a wet silicone tongue licking a tootsie pop. People have diverse reactions to the piece, Ben explained, from kids who simply enjoy seeing a lollipop being licked to grownups who have other ideas. Ben made the tongue out of Dragon Skin, a silicone used for special effects, and he molded it by making a cast of the tongue from a taxidermy bear. Water from an elevated water supply runs into the hollow interior of the tongue and then slowly oozes up to its surface, via tiny holes, to keep the tongue wet.

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Simone Davalos surprised and delighted participants with the R/C robot NASDAQ. A previous version of this bot used wheelchair motors and regular wheels, and lasted just a few minutes per battery charge. This version uses scooter motors and omniwheels which can passively roll sideways, reducing friction on turns, as well as propel the bot forward and backward. With the same battery pack, this new version runs for hours on a single charge (although it won’t go as fast).

NASDAQ’s lightweight metallic-looking body is simply cardboard covered with reflective mylar, and the patterned mylar and color gel panels on top fool some people into thinking that they’re solar cells. The robot was built at San Francisco State University by teams of students who worked in parallel on different parts, and after the robot was first assembled, an early trial inspired its name NASDAQ — it was going along fine until the bottom dropped out.

I also met Joel Rosenberg, who is working on the new Makerspace education effort. When he taught high school science in Boston, he and the three other teachers in the department had a combined annual budget of just $1500 for all materials– so he learned how to teach on the cheap. For example, he used a free and little-known old electronics workbook called “Electronics Tasks and Assignments” by Stewart Dunn. Despite its uninspired name, it’s a great workbook with example circuits drawn full-page size. Joel prints the circuits on manila paper and uses brass paper fasteners (brads) poked through the paper as anchor points for the circuit. On the back, he solders wire connections to the fasteners’ heads, and on the front, he cinches the fasteners’ legs together with a bit of heatshrink tubing, then bend them into little spring clips. Behold: a working circuit/diagram for pennies!

Luigi Anzivino taught people another way to make circuits with paper: by painting circuit traces with conductive ink. The people at his table were using black ink, which is thin enough to brush on with a paintbrush, making it easy to work with. Copper ink is more conductive, but it’s so thick that you need to squeeze it out of something in a thin bead. The ultimate is silver conductive ink, which is expensive but highly conductive and can be used in a modified ballpoint pen — conductive calligraphy!  The inks all need to dry before they can conduct electricity, and are available from, a site that caters to the tinfoil-beanie set and sells conductive inks as EMF shielding paints.

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A more traditional form of inking was demonstrated by the San Francisco Center for the Book, which brought a small letterpress, which is a beautiful tool. They also displayed some old printing blocks, like this one, for printing emergency wall posters with a cheerful brush script font.

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Don Rathjen helped me make a micrometer that’s capable of measuring hundredths of millimeters out of a screw, a small wood block, and other common materials. His design is a variant of a project from the PSSC curriculum, the high-school physics teaching program developed at MIT for US classrooms after Sputnik. The micrometer holds its test object between a wide washer and the flattened end of a #10-24 screw. Because the screw takes 24 complete turns per inch and a millimeter is about 1/24th of an inch (1/25.4 actually), that means the screw advances about 1 millimeter per turn. Secure a large dial to the screw, and after zeroing the micrometer, you can measure how thick things like hairs, magnet wire, and sheets of paper are by just turning the screw down loosely with a clothespin, and seeing where the dial stops.

No celebration of tools would be complete without TOOOL, The Open Organization Of Lockpickers. TOOOL members taught kids how to open cylinder locks via precise single-pin picking or more brute-force (but still gentle) raking. Here is an example of the latter:

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In the “Meet The Makers” program in the Exploratorium’s McBean Theater, electromechanical amusement designer Tim Hunkin called MIG welders “glue guns for metal” and admitted that, when welding, he sometimes just closes his eyes rather than wear a shade. Demonstrating another favorite tool, an angle grinder, he said “I know they’re teaching lockpicking at the other end of the hall. This is a lot quicker.”

Textile artist Moxie recalled the day when, one day, she got bored and wondered if her needle felting hook could make felt that wasn’t flat. After succeeding in making a felt ball, and started using felt as a sculptural medium and has rarely felted anything 2 dimensional since.

Chef and culinary author Elizabeth Falkner described the pink Rolls Royce and cityscape cake that she recently made for Muhammad Ali’s birthday party. Her competitive side felt that that was a pretty unbeatable achievement until she attended Pizza Expo in Las Vegas, and met someone who had made a pizza for the Pope. In the kitchen, Falkner uses a blowtorch not just to caramelize sugar on the tops of desserts, but also as a quick-n-dirty way to warm things up.

Mechanical artist Benjamin Cowden showed how he designs mechanisms with life-like behaviors by doing pencil sketches, then refining in 2D CAD for cutting flat metal pieces that he then welds together.

Maker Eric Stackpole told the story of the Hall City Cave, where local legend holds that a fortune in gold was abandoned at the bottom of a long water-filled shaft. Unsuccessful robotics-based attempts were made during both the 1980s and 1990s to retrieve (or disprove) this 19th century fortune, and it inspired Stackpole and David Lang to lead the OpenROV project, an open source underwater vehicle for telepresence. In just a couple of weeks, the two will go back to the cave with the latest version of the OpenROV and try to find the lost gold.

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Paul Spinrad is a broad-spectrum enthusiast, writer, maker, and dad who lives in San Francisco. He hatches schemes at

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