Toothbrush Robot Home Building Instuctions

A few folks have asked how to build Timmy the Toothbrush robot (hex bug style). Here are the instructions: 

Steps: #1 gather materials, #2 strip the wires of the motor about 1cm, #3 add double stick tape to the top of the tooth brush head, #4 stick on the motor and only ONE of the two wires - keep the other wire unstuck and floating, #5 squish the battery over the first wire and under the 2nd so it sticks to the tape, #6 use blue masking tape to make a switch that can pull the 2nd wire on and off the battery.

 Yup, pager motors #OldSchool

Yup, pager motors #OldSchool

Mechanical Circus

The project pictured below is a version of Ryan Jenkens' #MechanicalCircus. In our classroom we wanted to do something similar, but with a base the students could actually design and take home in a single class. My students will take this paper straw design and iterate on it over the next year. I can't wait to see what they come up with.

The theme we are starting out with this year in K-8 is simple hand tools before digital design. 3D printers and laser cutters are great, but we want to start by focusing on the power of short design cycles and rapid design iterations. 

 Somtimes a simple paper straw base is the best way to build a prototype. 

Somtimes a simple paper straw base is the best way to build a prototype. 

Fractions Rule, Fraction Rules (2nd Grade)

Why not give students early exposure to fractions? We start using rulers in early elementry grades. Why not put easily readable fractions on those rulers? Some students will pick it up sooner than others, but in all cases it is priming the mental pump for exposure to fractions in middle elementary school. The picture today is of a Victor ruler with brilliant hot pink background and a fraction caliper from Vinca. These are two must have investments in my classroom.  

 The play on words might be lost to the current generation, but "fractions rule" (they are really great, also, they are on a ruler - terrible puns today).

The play on words might be lost to the current generation, but "fractions rule" (they are really great, also, they are on a ruler - terrible puns today).

Piaget's Tool Box

I found Piaget's tool box! Really!! This is the actual toolbox that belonged to the famous educational researcher Jean Piaget - the father of Constructivism. There is no particular explanation I can offer as to why it was not put in a museum before this time. It was just sitting there on the sidewalk and no one seemed to want it, so I picked it up and took it into my classroom. Inside I found a few simple hand tools and some everyday materials, plus a few inexpensive items any serious scrapbooking grandmother would have on hand.

I was asked what I am going to bring into the classroom on the first day of school at St. Raymond. Answer: Piaget 's tool box. Along with the famous toolbox I will bring some LED's and Microbits and see what the students decide to build.

Looking forward to it!

*no actual thievery or skullduggery went in the writing of this blog post as I am only 99.9% sure I found Piaget's original toolbox, there is a small chance it was curated on my own from years of teaching.

 A few simple hand tools and some everyday materials go a long way to setting students up for success!

A few simple hand tools and some everyday materials go a long way to setting students up for success!

Paper Straws as Classroom Building Blocks

Over the last week I have been obsessing on paper straws. They are a great building material in the classroom. When I found the very weird sounding "Crop-O-Dile" tool I was hooked. This is not a paid promotion. I just love this tool for the classroom. You can connect paper straws, emery board, popsicle sticks and playing cards together with eyelets. Tools in classroom Makerspaces should be useful, cheap and plentiful. At St. Raymond having a one-to-one ratio of useful hand tools for students in the Makerspace is a priority. 

 Paper Straws make great building blocks for quick classroom prototypes!

Paper Straws make great building blocks for quick classroom prototypes!

One volt does not matter. Two, sometimes.

One volt does not matter. Two, sometimes. As an engineer I accepted standards and never questioned them. A 5 volt circuit needs 5 volts. Don't run it on 4 volts or 6 volts. After years of working with teachers and students new to electronics I am finding that keeping to engineering specifications only serves to make STEM/STEAM projects less accessible. 

Using a 3v coin cell to power a 2 volt or 5v LED is just fine. Forget the resistor, the battery has enough internal resistance on it's own. The 2 volt red LED will shine mighty bright for a long time and the 5 volt LED will shine less bright for even longer (days). You can take this further with powering the robust Arduino and most old school integrated circuits. 

Jim Keith at Electro Schematics wrote an amazing article summarizing his work testing the venerable 555 IC. I have found similar results with over voltages. Here is the reality: when working with inexpensive electronic components and the goal of engagement and education it is better to worry less about one volt and focus on getting teachers and students picking up and using components to build projects that make them smile.

IMG-9178.jpg

2D to 3D FAST

We added a strip heater to the front of our laser cutter so you can quickly go from a 2D geometric design and fold it into a 3D part. The sweet spot here is 1/8" acrylic that cuts fast on the laser and heats fast for bending. Why do we have the laser on a cart in the first place? When you roll the laser outside for cutting there is no worry about smell from cutting plastic and wood. Even an indoor air filter will leave a Makerspace smelling badly when cutting acrylic.

What is a billion (or two) transistors?

The iPhone has 2 billion transistors in the CPU! 
Wait, first, what is a transistor? If you are feeling intimidated by the question, or even worse, comfortable with not having any idea, then you are on the un-empowered side of the very real digital divide in society. If you are on the empowered side of the digital divide you might describe a single transistor as a kind of switch that allows electricity to flow or not flow depending on an input signal. The idea is that the transistor is always in an on or off state, a 1 or 0 state: a binary system, true or not true, high or low.

This summer in the St. Raymond Makerspace we have been developing curriculum that introduces a single transistor on a paper circuit to control a small motor. Students can build this circuit and gain some confidence and better understand the digital world around us.. What I wanted to cover in this blog post is one step after that. When someone knows what a transistor does, then how do we scale that up to understanding many transistors on a computer chip a.k.a. integrated circuit (IC)?

A great first integrated circuit (IC) to study is the venerable 555 timer chip. The different functions can be understood at a high level right away and a first project might take only a few minutes to complete on a breadboard. The problem is the person learning can not **see** the transistors and with only a nascent knowledge of how a single transistor works we go from practical knowledge to the world of theory because we are literally working with a tiny black box. Circuit schematics give us detail, but only build a mental picture. We can not physically probe the inner working of the tiny black box with a voltmeter.

So why not just build a 555 timer out of full size transistors and resistors? There are not that many to put together and we do have a schematic:) Once you get to understanding how a single transistor works then build this full size 555 chip. You can start to get a sense of what is going on inside of a simple IC. This is literally a "dis-integrated circuit" which is a lot of fun to say as a tongue twister when trying to emphasize the right syllable so as not to sound like "disintegrated".

When someone builds this full size model of a 555 IC they can then start to absorb some of the block schematics of the IC as meaningful information. Next year this will be a required project for every 8th grade student. Those students can then appreciate statements like "there are two billion transistors on an iPhone processor" because they actually built and played with exactly the same thing, admittedly with a few less transistors, but not less complex operating theory. To build this oversized is to help students and teachers jump the digital divide by going from ""tiny theoretical black box" to "large guts exposed and poke around in it box".

 The original 555 IC in the upper left .vs the larger than life version below made from full sized transistors and resistors. 

The original 555 IC in the upper left .vs the larger than life version below made from full sized transistors and resistors. 

Lock Picking - 5th Grade

A black box is a mechanism that someone knows the function of, but not how it works. Locks surround us. We know that if you put the right key in a lock and it will open, but most people don't understand the mechanisms in any more detail. Today in 5th grade we learned how the driver pins, key pins, springs work together to allow the barrel to turn when aligned at the shear line. It turns out the lock is not looking for a key, but rather the specific combination of crenellations (bumps) cut into the key. Alternatively, we can put a small amount of tension on the barrel of the lock and bump each pin up until we find one under tension and trap it in place, then move on to the remaining pins. Either way it is the same result - an open lock.

This skill is easy to master with a clear lock, but picking up the very subtle tactile feedback in the tools through one's fingertips takes, calm, focus and patience. We want students to leave class after this lesson seeing locks in the world as simple mechanisms they now understand - in the mind's eye they see clear locks everywhere - not black boxes. Our students will shatter glass cealings, now they also see every door as open and thier own choice to go through it or not.

 

 Thank you to Tony @ http://1585security.com for helping with this lesson and for the cross-section image.

Thank you to Tony @ http://1585security.com for helping with this lesson and for the cross-section image.

Self-Folding Flower - 6th Grade

At Makerfaire last Saturday I saw 3D printed shapes that had a fabric base so they were flexible. That lead me to self-folding shapes that use pre-tension on the fabric. From that I thought about using rubber as the printed part and combining that with pre-tension on the fabric. The result in the photo is a self-folding flower. It turns out we were not the first to think of the idea. Here is an excellent link to this technique.

 Above: The flower was printed flat and folds into shape because of pre-tension in the X and Y directions in the fabric.

Above: The flower was printed flat and folds into shape because of pre-tension in the X and Y directions in the fabric.

Getting to Know Stepper Motors - 4th - 8th grade Makerspace

Stepper motors are found in all sorts of everyday machines that require a precise movement. Today we took apart the same stepper motors that run the x, y and z axis movements in our Taz6 printer. Operational theory is one way to learn, but in the Makerspace we prefer to just take something apart and poke around inside and see what can be discovered. 

Stepper motors come in all shapes and sizes. The NEMA 17 designation of the motor we took apart refers to the size of the motor faceplate and distance between mounting hole centers. Students came to much deeper understanding of how a stepper motor works by actually holding at the rotor and energizing each coil with a power supply individually. We also learned a lot about how to design a rigid case that can hold a shaft to true center under heavy torque loads.

 A NEMA 17 stepper motor taken apart in order to better understand it.

A NEMA 17 stepper motor taken apart in order to better understand it.

A PD (Play Date) for SF Archdiocese Teachers

Today teachers from 40 schools gathered at St. Gabriel in San Francisco to enjoy a day of picking up both low-tech and high tech STEAMy tools, using them to build prototype projects that they can duplicate in their own classroom. Design Thinking was a lens for some of the sessions. Thanks to generous support of the San Francisco Archdiocese, schools were able to take home classroom kits of materials to duplicate the projects they prototyped in the morning sessions. This Play Date had a unique structure that paired technology teachers learning along side of classroom teachers!he light and motion machines were built from scratch, not part of kits. We talked a lot about the idea of assembly vs. making. 

 Teachers worked in pairs to use new tools to build unique light and motion machines.

Teachers worked in pairs to use new tools to build unique light and motion machines.

28 Miles of ABS Filiment

We have started to push the limits of the new Luzbot Taz 6 printer. This is a more complicated printer that can print in rubber, ABS, PLA and a variety of other materials. This means a lot of tweaking settings around stepper motor behavior and how the g-Code is generated. What is most amazing is that this is a student managed machine. Students are responsible for fixing and maintaining all of the machines in the Makerspace. With that context in mind it is pretty amazing to think that the single vase pictured above was printed with filament that when extruded through the printhead was 28 miles long and it printed with less than 0.01mm of error!

In the video below look to the left to see the CURA software simulation used to generate the tool paths for the Taz 6 printhead to follow while extruding the vase. 

Showing sliced Cura file and actual print side by side

Booting Up for the First Time - 7th Grade

Students in our 7th grade class built laptops based on the Raspberry Pi. There is a satisfaction of building something, then turning it on for the first time and watching it awaken. In the next few weeks students will evolve these Pi-Top kits further by designing and building from scratch small modules that will snap into the Pi-Top rails. These modules will be their own subsystems with seperate batteries so they can work within the Pi-Top, or out in the world on their own. The design challenge is to build within physical constraints as students prototype their modules. 

 7th Graders assemble the Pi-Top chassis and install the Raspberry-Pi boards.

7th Graders assemble the Pi-Top chassis and install the Raspberry-Pi boards.

Pi-Topping with Mu and the BBC Microbit!

Running at full STEM>STEAM into the new year at St. Raymond we will be one of the lucky schools using the Pi-Top, a unique enclosure that turns a Raspberry Pi into a laptop, but not just any laptop, but one that is designed for hardware hacks. Getting ready for the upcoming semester we have been experimenting with using the Mu editor for Micropython on a Pi-Top with the BBC Microbit. 

 

 The Pi-Top pushing MicroPython code to the BBC Microbit

The Pi-Top pushing MicroPython code to the BBC Microbit

Hacking Minecraft - 5th Grade

Today the 5th grade class used the Python 3 programming language to create large structures quickly in Minecraft. This lesson reinforces the academic standard of calculating volumes in 3D space (x,y,z). Students built structures in Minecraft without playing the game directly. They were able to open the Minecraft window, then toggle over to Python to write the code and watch the results in as they executed the code. The largest block made was 216 Million units in volume. The lesson combined sections from Peter Farrell's excellent book Hacking Math Class with Python and the Raspberry Pi Foundation's book Hacking and Making in Minecraft.

 

 It is a lot of fun to make huge objects quickly in Minecraft with the Python programming lanague!

It is a lot of fun to make huge objects quickly in Minecraft with the Python programming lanague!

Hosting SF Archdiocese Schools for a Fun PD (Play Date)

Today St. Raymond's hosted Tech and STEM/STEAM teachers from around the SF Archdiocese for a fun day of connecting software programs written in Python to the physical world. As a group we explored code that changed the physical world, writing Python to turn on LED lights on a breadboard. Now the teachers at each of the represented schools have the knowledge to share these exciting new skills with their students! We are taking it to the next level together!

Reference links for the hosted PD on 11/27/17:

Getting Started with Processing

Getting Started with Python in the SenseHat

Hacking Minecraft with Python

 Nom Noming on a Raspberry Pi (a $35 computer) after Thanksgiving!!!

Nom Noming on a Raspberry Pi (a $35 computer) after Thanksgiving!!!

Tools for Adults - After School MakerSpace

Students participating in the after school makerspace at St. Raymond use tools designed for adults because our students will become adults. In the pictures below you will see a 4th grader picking up a full-sized 15amp power drill to cut into 4" PVC pipe and a 5th graders operating the drawbar to change out an R8 collet with holding a tungsten carbide fly cutter. 

Our students use the exact same tools engineers use in the real world because they aspire to solve real world problems!

 Above Left: A 4th grader using a full sized DeWalt Drill           Above Right: Changing out an R8 Collet

Above Left: A 4th grader using a full sized DeWalt Drill           Above Right: Changing out an R8 Collet

Melting Metal - 5th Grade

Soldering is the process of heating up tin alloy to melting temperature and allowing the molten metal to flow between two electrical components and form an electrically conductive (and mechanically permanent) joint. Soldering is dangerous. With the tip of the soldering iron at 750° bad things can happen quickly. Today our 5th grade class stepped up to the responsibility plate and were allowed to solder in a supervised setting. Kudos to the class for an injury free day and for taking safty so seriously. The students not only did well, but they were great teachers to each other!

 Studets work in pairs to help each other solder safely.

Studets work in pairs to help each other solder safely.