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.
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".
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.
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.
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.
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.
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.
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.
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.
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.
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
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!
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!
Last year the Fund-A-Need raised money to get 75" smart boards in the K-8 classrooms. Today we finally got them installed!!! In the Mechatronics room we were using the smart boards 20 minutes after they were installed for a lesson in Autodesk Fusion 360. Today students work with symmetry and patterning tools as well as applying textures to their designs. It was very powerful for students to be able to share their work in real time with the rest of the class.
Today our 5th grade students built on the work of our 4th graders in Fusion360. After looking at (x,y) vs (x,y,z) we took the basic metal donut shapes the 4th graders created and added materials and textures. The rendering process uses a technique called ray tracing where we calculate the path of each photon, including how it would reflect and refract in glass and metal. At first glance the image below might just look like a photo of a glass sculpture in a galley. The reality is this is a virtual model one of our 5th graders constructed in Mechatronics class today. This 3D model can then be animated further in the virtual world or become part of our physical world depending on the tools applied to it by the student. A few other 5th grade class examples here, here and here.
Autodesk Fusion 360 is a professional engineering design tool students in high school and college start to pick up. Today we gave it to our 4th graders. We looked at how a profile (any enclosed two dimensional area) can be revolved around a line into something resembling a donut (torus). We then arranged copies of those donut shapes into an intersecting circular pattern. The result is below:
Thanks to Mrs. Hamilton for bringing out Eclipse Glasses during out teacher PD today!
There is a huge leap in complexity between simply making a machine that will exist on its own and making a part to work inside an existing machine. At St. Raymond our Mechatronics classes are decidedly "non-robot" and "non-car". We want students of all interests to pick up Mechatronics as a skill, so our classroom projects don't look like the stereotypical robots and cars of other programs. We design and build things like microprocessor controlled water drinking bugs and wooden speakers.
Our after-school Makerspace is very different. Students can walk in with any interest and simply build what is in their mind's eye. Projects are anywhere from a few hours long to 30 hours long (like in this case). We had a student who is totally into Radio Control race cars and wanted to design a part to improve on the design suspension of a factory product. This meant 1) Understanding the Geometry involved in the suspension system, 2) Identifying the current and modified performance characteristics they want to see and 3) Design and building a part with very, very tight tolerances to meet the stated goals for performance characteristics.
The student that embarked on this project is 9 years old. The student spent every available hour in the after school Makerspace at St. Raymond learning Tinkercad and how to set up, use and maintain the Dremel Idea Builder 3D printer. Thirty+ hours, and a many iterations later, the student installed a successful prototype part into the suspension system that is more than 20% lighter and modifies the car's suspension geometry to the desired 1.4° of camber angle. The part had to fit with the other parts from the factory perfectly. It did. We don't have a camera lens big enough to capture the sense of pride-in-craft that the student showed while driving the car around those initial laps with their newly minted parts successfully installed and an engineering problem solved!