Spray Paint Planets

One of my students really got into spray-paint art this year, especially planets. By the time she was done she’d completed over two dozen pieces; some on paper, some on wood, some on clear plastic or acetate, and some of which we backlit with LED’s. Her paintings are all over the Makerspace, which generates a lot of interest.

However, now that this student has graduated, we’ve had to find another way to teach the process. I’m using the above video as a quick introduction to the process (note: it starts at 36 seconds because the author uses a single rude word in her preamble).

Area of a Triangle

The area of a triangle is one half of the length of the base times the height:

 A = \frac{1}{2} \cdot b \cdot h

Six triangles with the same area.

For my Geometry class, I made this set of six triangles to show that as long as the base and height are the same, all these triangles will have the same area.

Each student measured a triangle and found its area, which is a useful exercise in itself to get them to transfer the ideas and equations out of the book, and then the all compared their results. Their calculated areas were all within 5% of the actual value, which was not unexpected given that some small measurement error was inevitable.

Since you can use any side as the base, not everyone measured the equivalent side and height, so I had to demonstrate that similarity as I summed up the exercise.

For the next time I use this set, I’ve marked the one side that is 10 cm on each triangle for students to use as the base.

CNCing Aluminum

All of a sudden, we have two projects that require us to CNC aluminum.

We managed to make it work with the regular 2-fluted 1/8 inch bit. It cut pretty easily with the settings:

  • Bit: 2-flute straight, 1/8 inch
  • Feed Rate: 254 mm/min
  • Plunge Rate: 76.2 mm/min
  • Depth per Pass: 0.2 mm

Of note: For the very thin material we tried (0.8 mm thick), I found that instead of using regular tabs, where the machine cuts through most of the material and just leaves a thin tab holding the cut-out pieces in place, just leaving gaps in the design seemed a better option. We have a slight tilt to our surfacing table and it was just way too easy to cut through the entire place where the tab should have been.

Bright and Shiny Things: Programming with LED’s

Teaching programming using the LED light strips is going much better than expected. I tried it with the 9th grade Algebra class during our weekly programming session using a set of coding lessons I put together. I went so well that though we started by having everyone (about 10 kids) share two LED strips, by the end of the year I had three students from that class build their own.

Student built LED strip.
Student’s LED strip on a sword. The battery can power it for at least 15 minutes.

The coding lessons are still a work in progress, but it has them learn the basics by running some of the test programs, then then explore sequences using for loops. There are a lot of directions to branch off after the for loops. I’ve had some of my Algebra II students make static patterns using linear and exponential functions, while a couple of the kids in my programming class used different functions to make dynamic lighting patterns; our hydroponic system (see here and here) now has a neat LED indicator that runs different sequences depending on if the pumps are running or not.

Some of the students who built their LED strips in the Makerspace posted about their projects: LED Thingy and LED Light Strip Project. The process (rpi-led-strip) is not too hard but required them to be able to do a little physical computing (with Raspberry Pi’s), use ssh and terminal commands (terminal instructions), and then run and write python programs.

Raspberry Pi that controls one of the LED strips from a student’s project.

Since the setup uses the same GitHub repository (rpi-led-strip) it’s also easy to update some of our existing projects like the Wall Anchor.

Wall anchor project.

I am amazed at how much the students have engaged with what are, ultimately, very simple systems (a Raspberry Pi and a strip of 20 lights), and I’m really excited to see where it takes us.

3d Printable Microscopes

A few interesting, low-cost but potentially lab-grade, microscopes that would be great Makerspace projects for students.

OpenFlexure: Out of the University of Bath, this has a Raspberry Pi at the core that can control the stage, focus, and sensor (using the RPi camera module). Since it’s modular the cost varies with the image quality you’re aiming for, but it looks like you can achieve even high resolution results relatively cheaply. They have great detail on their website, including their own version of Raspbian to install on the Pi, so this looks like an good starter project.

UC2: I really like the look of this building block, LEGO-style, system. It seems extremely flexible and there are some interesting projects that go beyond your standard microscope. There are a lot of designs you can go with, including an Arduino or using a Raspberry Pi and camera, but they claim to get good results just with smartphones. This is a big, sprawling project, which suggests a slightly steeper learning curve.

Hat tip to Maggie Eisenberger for introducing me to these.

Making 3D Periodic Tables

Laser cut, 3d periodic tables.
Laser cut, 3d periodic tables.

Ms. Fu’s chemistry class were given a project to make 3d periodic tables based on the properties of the elements. A few groups went with Makerspace options, using the new vinyl cutter and laser.

3d Periodic Table showing electronegativity.
3d Periodic Table showing electronegativity. Laser cut.

Periodic Table relief based on ionization energy. The blocks on this one have 1.5 inch square bases. The colors for the different regions  use stains including tea (assam) and blackberry juice extracted from berries from the canes on campus.
Periodic Table relief based on ionization energy. The blocks on this one have 1.5 inch square bases. The colors for the different regions use stains including tea (assam) and blackberry juice extracted from berries from the canes on campus.

The part that took the longest was marking all the columns for cutting. A worthwhile assignment would be to write a program to automatically make the cut-marks in an svg file that can be etched with the laser.

Periodic Table column heights based on density.
Periodic Table column heights based on density. Laser cut.

Paper columns and vinyl cut lettering on this periodic table.
Paper columns and vinyl cut lettering on this periodic table.

The Wall (Mural)

Our seniors wanted to leave a mark, so after their initial application to paint the outside wall of the gym was turned down, they went with a mural on the inside–in our Makerspace.

For this project, we wanted to create a mural on the basementnasium wall. First, we measured the wall and went to Home Depot to get enough paint, paint brushes, drop cloths, and tape. Then, after cleaning the wall with a damp cloth, we covered the wall with tape in a triangular pattern similar to one we found online. After that, we used pencil to mark each triangle with a letter corresponding to one of the six colors that we bought. It took us the majority of the project to paint 3-4 coats on each triangle, and on the last day we pulled it the tape and touched up any mistakes with white paint.

Throughout this project, we found out that some people know how to paint, some people learned, and others didn’t learn. BUT IT WAS SO MUCH FUN!

-Team: Elliott, Abby, John, Zoe, Mary, Annemarie, and Josiah

-Abby R.