For Halloween this year, I went as a robot, wearing a silver dress with a slowly pulsing LED heart glowing visibly under the fabric.
The LED is a one watt white LED, which we’re running at about 50 mA. It has a wide viewing angle, and the star-shaped mount lies conveniently flat. The LED is wired up to the PCB with a pair of twisted magnet wires. Magnet wire is flexible and thin, which makes it hardly noticeable under clothing. It is controlled by ATtiny2313 (running the code from our Mac sleep light pumpkin project) and powered by three AAA batteries. The PCB corners were rounded off so it wouldn’t be stabby.
The dress was fully lined, which made it very convenient for mounting electronics. I pinned a makeshift pocket onto the liner, and tucked the battery holder and PCB in the pocket. I could feel the battery holder switch and turn it on and off through the fabric.
The LED was taped to the dress liner with medical tape to hold it in place. An extra piece or two of tape held the wires to make sure there was appropriate slack for movement. (A note on tape: use the good stuff. The cheap paper tape in the off-brand first aid kit only stuck to itself and the magnet wire. 3M plastic medical tape worked great and came off easily.) This makes it easy to disassemble after Halloween.
renegade_geek posted a set of Pumpkin Faces on thingiverse for the EggBot. They’re cleverly arranged in layers so that you can hide and show the different eye, nose and mouth options.
A collection of separate eyes, noses and mouths, each set on its own layer, for a customized jack-o-lantern/ghost face to be printed with the Eggbot. These were made to print on ping pong balls. You may need to adjust for eggs and other less regularly shaped items. I have included a “faces menu” PDF so that you can clearly review your choices. This was really helpful in a classroom situation.
If you solder, you’ve likely come across an “untinned” tip at some point— that’s when the tip of your soldering iron loses its shine, and doesn’t easily wet to solder any more.
Once your tip gets this way, it doesn’t make nearly as good of a thermal contact to whatever you are trying to solder, and it simply doesn’t work well. Soldering can take 2-10 times as long, and that isn’t good for your circuit board, components, or mental health.
You can sometimes re-tin the tip by melting fresh solder onto it, but that can be challenging, because the whole problem is that the tip isn’t melting solder. It’s particularly hard to keep tips tinned with modern lead-free solder, because it needs to get even hotter to begin melting. If you get to this point, you might think about even replacing the tip.
But before you throw that tip away, instead consider using one of the “old standard” solutions, which is to refurbish the tip with a tip-tinning compound. And we came across the most classic of them in one of the most unexpected locations. Continue reading Soldering Tip Tinning with Sal Ammoniac→
With all the pumpkin spice jokes flowing around the internet recently, it’s time to remind everyone how easy it is to make your own pumpkin spice flavored things. Way back in 2007, we published a recipe for making your own pumpkin spice chocolate truffles (hint: no pumpkin involved) and you can use the spice blend on anything at all. (Pumpkin spice Raspberry Pi, anyone?)
We’ve just given the WaterColorBot a little bump up to kit version 1.5. The new version now comes with a pair of beautifully machined aluminum winches.
The winches are precision cut on CNC machines and anodized clear. We add a few extra little parts (flat-head rivets to wind the winch around, screws, and a stamped and polished stainless steel “clamp” to hold the string end), and wind them with the same “100 pound” Spectra cord as we did before.
We described the process of making and winding our older laser-cut wooden winches in our blog post about the making of the WaterColorBot, and again in our post about the winch cutting jig. For better or worse, transitioning to the new aluminum means that we’re no longer using our older wooden winches that we described in those blog posts. But in the end, these new winches are a better, more elegant solution.
Umbrella Upcycle is a project site filled with things you can do with cast-off and broken umbrellas, including our Better Bat Costume. The project is aimed at reducing the numbers of umbrellas that end up in landfills, and they link to project tutorials, methods of recycling, and recommend places to donate both umbrellas and finished umbrella projects.
There are culturally common activities like wine and cheese tastings that explore variations of a particular theme. There are also flavor tripping parties specifically for trying out the taste bud altering miracle fruit. And there are molecular gastronomy and modernist cuisine that are intended challenge your expectations of texture and flavor. In the spirit of these kinds of experiences, we came up with a wide-ranging set of interesting (and sometimes challenging) items that can be shipped through the mail and shared between internet friends.
The goals of the project include isolating a few interesting flavors that are not normally tasted on their own, understanding a bit about the ways that shape and texture affect flavor, and play a bit with some of the available “mouth altering” spices and flavors.
Most of the items we included in our tasting kit are from Indian or asian grocery stores. For herbs and spices, getting them from a shop with high turnover will help in obtaining fresher spices that are more full of flavor. They’re also likely to be less expensive at places that expect larger quantities of spices to be used in foods (we’ve written about this before). Ethnic groceries are better at this than mainstream ones, and places with bulk bins can be just about the worst. A few items we shopped for online, and a couple came from our garden.
For tasting order, we opted to start with more subtle flavors and end with mouth-altering ones. Our general itinerary was divided into four parts: flavors & scents, shapes, adventures, and light.
Of special note: many people are sensitive to particular (and sometimes esoteric) food items. Be sure you have discussed food allergies with all participants before plying them with unknown ingredients. Decide if you want to try things before announcing what they are. Have water and neutral flavored crackers or bread for cleansing the palette between flavors as needed or desired.
One of the joys of life is introducing people to new flavors and textures that you love, whether they are from your own kitchen or your favorite restaurant. Every so often, that will backfire, when someone ends up not liking your beloved dish. But sometimes you’ll see that “eureka” moment when someone lights up from the new experience. Eating involves many kinds of sense perception, including smell, taste, texture, temperature, and sight.
Part one: Flavors & Scents
Fenugreek Leaf (Methi): fenugreek has an aroma reminiscent of maple syrup and is one of the magic ingredients in tandoori marinades. Crumbling dry herbs in your fingers will help release aromas.
Makrut (Kaffir) Lime Leaf: a crucial ingredient in many Thai curry pastes and soups. This double-lobed citrus leaf is available fresh at many asian groceries, and we’ve written about it before.
Curry Leaf: used in south Indian cuisine, such as the soups you find at dosa shops. We have a little curry tree, but leaves can be obtained fresh at Indian groceries.
Ajwain: spicy, somewhat reminiscent of thyme or oregano. Also from Indian cuisines and spice blends.
Saffron: always used in very small amounts due to its potency and expense. Almost never tasted alone.
Chat (Chaat) Masala: used primarily on Indian snack foods. Key spices include black salt, mango powder, cumin and asafoetida. Try it on some fresh fruit.
Black Salt: very sulfurous pink colored salt mined from the Himalayas.
Truffle Salt: an excellent way to experience the heady aroma of truffles. Try sprinkling it on vanilla ice cream.
Part two: Shapes
Sugar Crystals: these large (~1/4 inch) sugar crystals are available at Indian and middle-eastern markets, sometimes labeled as “sugar cubes” despite their elegant shapes. They don’t seem as sweet as granulated sugar because of the low surface area to volume ratio.
Salt Flakes (hopper crystals): because of the huge surface area, these taste even saltier than granulated salt. Great for when you want to have lots of salt flavor and are sprinkling on a surface that will not dissolve the salt. Trader Joe’s is selling small containers with huge crystals. Alternately, Maldon Sea Salt Flakes are large enough to see the crystal structure.
Shredded Red Pepper: we came across these dried pepper threads at a Korean grocery store and have been garnishing our soups with them ever since. They’re preserved with salt and rehydrate to show the cross section from the center of the fruit to the skin.They’re beautiful and spicy, but not as spicy as red pepper powder because of the difference in surface area.
Part three: Adventures
Citric Acid: we found large granules of this at an Indian market. One big granule is enough to make just about anyone pucker. This is the full-strength version of the powder that is used to make sour candies sour.
Sichuan Pepper (Prickly Ash, Wild Peppercorn): one of the components (hydroxy-alpha-sanshool) triggers an anesthetic reaction. After chewing on a couple of these husks, your tongue will go numb and tingly. It increases your ability to eat super spicy foods, and has been described to us as “a party in your mouth.” We’ve also seen very panicked faces of people who just wanted the sensation to stop. Some people don’t seem to be as sensitive to it, or perhaps didn’t get very active pieces, and they usually find the lemony flavor to be pleasant.
Super Soda Gum: we discovered this great bubble gum through the Candy Japan subscription service and we now purchase it at our local Japanese grocery store. It has a powerful punch of fizzy powder inside, which makes your mouth foam up like crazy. It is awesome good fun, and it seemed to help the sichuan pepper effect to subside. Even after the excitement from the foam settles down, it is really good quality gum.
Miracle Fruit Tablets: we got these tablets from Amazon. They’re a little bit expensive, but the miraculin binds to sweet receptors on the tongue, making sour foods seem sweet. The berries are also available, but are more expensive, and harder to get shipped.
Citric Acid (again): after dosing with the miracle fruit, citric acid tastes like candy. Be careful, or you’ll inadvertently eat a lot of highly acidic food because it is so fun. Try other sour foods like lemon, lime, grapefruit, vinegar, and tamarind.
Part four: Light
Wint-O-Green Lifesavers: sugar crystals are a triboluminescent material, meaning that when you crush them, they emit light. However, they emit ultraviolet light, and so we don’t normally get to see the effect. Wintergreen oil fluoresces blue, so eating wintergreen flavored candies in the dark in front of a mirror or with friends will let you see it. Go into a very dark room. Wait until your eyes are accustomed to the dark. Bite the mints with your teeth to crack them to see the glow.
Asafoetida (Hing): a very powerful garlic and onion substitute from Indian cuisine.
Seaweed: for someone who hasn’t been exposed to the flavor of dried seaweed, it can be a shock.
Dried Sumac: a sour fruit used in the spice blend za’atar along with sesame seeds and dried herbs.
Tamarind: a sour fruit that is less well known in mainstream American cuisine, but can be found in many familiar sauces (even some Worcestershire sauces). Commonly available as a paste or as pulp.
Other less common fruits, such as dragon fruit, soursop, jackfruit, and durian.
Fresh vs. freeze dried vs. canned textures and flavors.
From our group came the suggestion to create a flavor symphony, walking through various movements of flavor rather than isolating each one. It could be interesting to add more familiar herbs like mint, thyme, and rosemary to the mix.
An exploration like this is fairly simple to lead when everyone is in the same place, but can also be done remotely. We packaged up our ingredients into little bags and tucked them into plastic organizer boxes (commonly available from the dollar store) to conceal the contents until the right moment.
The list above is strongly influenced by our personal experiences and cooking preferences. Depending on your background, things we find exotic may seem perfectly normal. It is interesting to see which ingredients stir up memories from the participants, and which are new to them as well. If you come up with other ideas, we’d love to hear about them!
Jenslabs has published a thoughtful and thorough evaluation of a number of currently available rollerball and gel pens. He tested them using his Circlon machine.
One thing that anyone who as ever built a drawing machine realizes, is that to get quality results you need a quality pen. There are millions of pens out there, but after a little trial and error I realized that rollerball pens or pens with gel ink are the best pen types for my machine. Both rollerball and gel ink pens use a water based ink that is less viscous then the oil based ink used in ballpoint pens. The Circlon machine sometimes move very fast, so the pen has to be able to release enough ink to make solid lines even at high speed.