Category Archives: Everything Else

It’s Just Math

image by Bryan Kennedy
I loved this little piece by Bryan Kennedy titled “It’s just wood.” A concise philosophical statement about the freedoms that come along with knowing how to make things.

The same approach applies in so many different contexts.  Sometimes, it’s just aluminum, just software, or just silicon. It also reminds me of what a physics professor of mine used to say when explaining how simple something was: “It’s just math.”

How Egg Crate Foam is Made

Ever wonder how they make foam rubber into an “egg crate” shape? You can tell that it isn’t molded that way, because there is not a smooth skin on the surfaces. And it clearly isn’t milled to that shape, since it comes in matched top and bottom pieces that are cut from the same initial block of foam. So how is it done? Amazingly enough, it’s done with a bandsaw.

Egg crate, acoustic, and other shapes of “convoluted foam” are cut with a special machine called a convolutor, which uses powerful rollers to feed flat sheets of foam rubber into a high-tension bandsaw.  The rollers are covered with bumps that stretch and distort the foam such that the saw cuts to a variable depth, with extremely little waste.

You can watch the process in this video from Italian Cutting Systems (noting that the bandsaws are hidden behind protective covers):

Linkdump: May 2014

Highlights of the 2014 Bay Area Maker Faire

BAMF 2014 77

The 2014 Bay Area Maker Faire was an amazing, amazing event. We took hundreds of photos, which we have posted in a flickr set here. Here are just a few of the highlights— both technological and artistic, and we’ll be featuring several more over the course of the next week or so.

(Above: Rolf and Abhishek show off the new Arduino Zero in the Arduino booth.) Continue reading Highlights of the 2014 Bay Area Maker Faire

Linkdump: April 2014

Pi Day is Here

Or, if you prefer, we’re halfway (well, 44% of the way) to Tau day, 6/28.  A fine day to watch the Vi Hart‘s Anti-Pi Rant. And, a fine day to round up some of our finest Pi, Pie, and mathematics projects:

Pi Blanket   Apple Pie

Pi blanket for Pi Day, and the Apple Apple Pie!


Earrings 2   Sierpinski Cookies-11

Sierpinski triangles out of polymer clay, and fractal cookies.

Fractal Snowflake Cupcakes - 24 fabric klein bottle

Fractal snowflake cupcakes, Fabric Klein bottle

Snowflake generator SymmetriSketch 2
Vector Snowflake generator application, and Symmetrisketch— for exploring other symmetries.

Christmas fractalSconic Sections
Christmas Chaos and Sconic Sections

Evil Mad Scientist Linkdump: March 2014

Back from the dead: The Evil Mad Scientist Linkdump. Last seen circa 2010, the Linkdump is our occasional collection of interesting links. You can find our archived linkdumps here.

Designs for Eggbot by RoboGenius

We’ve been watching the work of RoboGenius for quite some time. He has created some of the neatest non-geometric work anybody has done on the Egg-Bot. Recently, he uploaded a number of his designs to thingiverse, which means you can try them out, too. He has also been posting great pictures of them to flickr. When asked in the Egg-Bot user list how he created them, he posted:

The short answer is that it’s all done line by line in Inkscape.

The slightly more tedious answer is that it starts with an image (generally something off the web, or that has some significance to me), then I import that image onto my 3200px X 850px template in Inkscape and position it where I want it on the egg/ball. I then take a look at the image and decide how many color layers I’ll be needing for the plot and add those to the project, naming them sequentially followed by the color I use for the layer (for example: 1 – Yellow, or 5 – Black). I always begin with the lightest colors first, and generally end in black. Then it’s simply a matter of tracing over the picture on the correct layer using the bezier line tool (Shift + F6), and bending those lines with the path editing tool (F2). Once I get the basic lines created, I’ll create and fill any solid shapes using the EggBot Contributed Hatch fill extension (spacing should be set to 6 for eggs). To add shading, you simply go over the same places a couple of times with the same color, which can be achieved with Copy and Paste, and occasionally the shading can be enhanced by altering the angle of the line to match the angle of the shape or intended shadow (the Master Chief design is a good example of this technique).

That’s pretty much it. To finish off the project, I like to color all of the lines in a layer to match the marker used in that layer, then delete the layer with the picture in it.

Thank you for generously sharing both your designs and your techniques, RoboGenius!

Senko [Flash]

Tatsu Iida, a member of oxoxo [zero by zero] wrote in to tell us about the interactive LED installation entitled Senko [Flash] which they showed at the Tokushima LED Art Festival in April.


They used a Peggy 2 to drive a field full of LED illuminated spheres, along with IR sensors to detect visitors entering the array. Each new person would trigger a new sphere to light up and move through the field.

閃光 [Senko] - Tokushima LED Art Festival

This is the largest installation we’ve ever seen based on the Peggy 2.

閃光 [Senko] - Tokushima LED Art Festival

Thanks for sharing your incredible project with us!

Links to many more Peggy 2 projects are on the wiki.