Friday, April 22, 2016

LogoTurtle Constellation

A conversation about how the LogoTurtle and ink work led to this project starter.

What better place to play with ink blots than drawing constellations? Since I am an Aries, I found a nice image of the constellation that also modeled the relative brightness of each star.

I used a protractor and a ruler to measure the degrees that the LogoTurtle would need to turn to drive to the next point in the constellation. Conveniently one distance between stars in this image is five centimeters. In order to translate the real distances into LogoTurtle steps, I used the five centimeter measurement as my basis, equating it to 100 LogoTurtle steps. I remarked to the students around me at the time that I was using algebra to figure out the information I needed for my program, so pay attention, kids!

I programmed the procedure to put down the pen and then wait. When the LogoTurtle gets ready to move to the next position, it picks up the pen. I had to play around with the wait time, and it still needs debugging. The goal is to get a good pen bleed where the stars are, which would also provide an element of randomness to each piece produced.

I added this project to the LogoTurtle Curriculum site.

Wednesday, April 6, 2016

Passive iPhone Amplifier

I was taken by Reid Bingham's low-tech iPhone amplifiers he designed for a workshop. Made from wood with circles of decreasing diameter cut in them, they are a perfect solution that require no batteries.

photo by Reid Bingham

I really like this project and spent some time thinking about how to lower the threshold for this project. How could I teach people to build these if they have limited woodworking skills or are meeting in a space without power tools?

I opted to use insulating foam, which is available in a 2 foot by 3 foot by 1 inch thick sheet at my local big box. I also used a snap blade knife, a cutting mat, the Windfire Designs Circle Tool and a T-square.

I sized up my iPhone and decided a four inch square piece of foam would work nicely for my first build. I cut four of these squares.

I used the circle tool to cut two circles from two foam blocks using the snap blade and the circle tool as a guide. One circle is larger than the other. The key to cutting the foam, I learned, was shallow cuts and sawing motions once the knife is deep in the foam. I shaped the circles a bit with the knife, too.

I gave the blocks a quick sanding after testing on the fourth piece of foam I ended up not using. 

Like Reid, I used rubber bands to hold the blocks together. The phone fits into a slot I cut in the third piece of foam. There is a circle cut below the phone slot so the speakers are unobstructed.

It definitely makes the phone's sound fill the room! Depending on who is in the room with me, this is a good thing or a bad thing!

I think the use of foam, while presenting challenges of its own, does lower the threshold for this project. People who might be unfamiliar with working with wood can gain fluency using a knife and experimenting with subtractive fabrication. A foam cutting hot wire would be an interesting addition to the tools, at least for the straight cuts, and would provide a cleaner finish. There is nothing keeping the shapes from being more than square, either! 

I coated the foam with two layers of spackle that included primer, allowing it to dry between coats and sanding, too.

Afterwards, I used a quality spray paint with built-in primer and gave the amplifier a nice, even coat of paint.

After letting the under coat dry, I used a crappy black spray paint to give it a second light coat of paint. This provided a great oxidized look with the aluminum colored paint underneath.

Vinyl feet finished off the amplifier and made the model seem "lighter" by elevating it slightly off the table.

I was really happy with how this project turned out. I think it is very scalable: anyone you can trust to use a knife can build one of these. Give this idea a try and let me know how it goes.

Sunday, April 3, 2016

LEGO Tinkering

I insinuated myself into a project that a few of the guys at the Exploratorium are currently working on, intriguing LEGO constructions and machines that make art. We are using the Twitter hashtag #LEGOtinkering to share our creations, techniques, and art.

Most of the machines are built around LEGO Power Functions motors and battery packs, though I am also using Scratch and WeDo motors and a USB hub and an RCX brick running MicroWorlds EX Robotics Logo and RCX motors.

Each of my explorations have led me to new understandings of gears and gear trains, linkages, motor placement, and the art that results from different types of movement. The explorations have been useful for my collaborators, too.
It is rewarding for me to be able to collaborate with Ryan, Amos, and Sebastian on Twitter, to swap ideas, parts, and techniques, and to further the progress of our LEGO Tinkering robotic overlords.