Next have them chart out the values of the circumference and diameter of each circle. The circles should have a wide variation in size. At the end, when they have taken all their measurements and recorded them, the aha! moment should occur. The final column in the chart should be the ratio of the two values, calculated to several decimal places. All will be close to 3.14, the value of pi. It won’t matter what units they used, or the size of the circle. Pi is pi. There will be some discrepancies due to measurement errors and calculator rounding, and those subjects are worthy of discussion because anticipating these sorts of errors will help in any further experiments and data collection long term.

For other resources on Pi Day, visit:

http://www.piday.org/

Pi Day At The Exploratorium

There are three basic iterations of design in terms of dimension. 3-D objects can be printed directly or cut out on the mill or lathe. Two dimensional objects can be cut on a laser, CNC plasma cutter, or they can be milled as well (technically this can be considered 2.5-D since there is some accounting for height). Finally, 2-D shapes can be designed to be assembled into 3-D objects. This is commonly seen when acrylic or wood is assembled from flat pieces cut on a laser cutter, or metal cut on a CNC plasma is welded into a 3-D part.

As we teach STEM students about the concept of design for manufacture, we ask them to consider time as a cost factor. The time it takes to assemble a 3D object from a set of 2-D parts can be significant. The assembly process can also introduce errors into the final product. We analyze the number of T-slots in an acrylic project box, or count the number of holes that need to be tapped,  all with the notion of reducing sources of various costs.

Recent research in Germany has provided an ingenious solution to some of these cost factors for those using acrylic to manufacture parts on a laser. Rather than cutting the parts, laying them out and assembling them, some of the joints are actually bent by applying selective laser heat and drawn down by gravity. What this means is that the creation of 3-D parts is possible using 2-D materials, reducing costs dramatically. It is an extreme example of rethinking the design for manufacture process itself, and should be a great inspiration to students. Extending this inspiration into the classroom as part of student engineering practice is highly recommended, and here is the connection to make it happen. The challenge is to make the process of 2-D laser cutting into a selective bending process that works for your machine. This will engage the students in genuine science and engineering because the process has not been adapted to standard inexpensive laser machines.  Watching the video (and reading the research paper) will provide some insight as to what needs to be done. The key is to reduce the intensity of the laser beam and broaden its path in specific locations that will permit bending in the desired area. One possibility is to apply a material or color band on the material that will diffuse the laser and reduce its power. Another is to program the laser to adjust speed and/or power level in different areas along the tool path.  The other important factor is the platform and its height must be configured to allow movement of the piece toward the ground. Pay particular attention to the use of a servo motor to rotate the material shown in the video.

This is a project for a team of advanced students. They will need to be familiar with the properties of acrylic as well as the machine and its software. Remember that lasers are dangerous if used carelessly, and the protective cover should always be used. In some cases eye protection should be worn. Whether or not your students perfect this process, they will be engaged in genuine research.  If they are successful, they should take every opportunity to share their findings at science fairs, social media and maker web sites. Students who are given the opportunity innovate and experiment in this way are modeling STEM education the way it should be whenever possible. Try it or something similar in your classroom.

Click here to view the video on YouTube.

Click here to view the video on YouTube.

Enter the open source movement and the cheap laptop computer. There are too many examples of how open source software has made STEM education much more accessible to students to cite here, but now integrating inexpensive hardware with software can make your STEM students into real scientists. The great thing about cheap laptops and tablets available today is the way  in which clever software and sensor design can take advantage of the computational power of these devices to turn them into instruments that were once the exclusive purview of private laboratories and universities. A corollary worth mentioning is the advent of microcontrollers such as the arduino and raspberry pi that can do the same thing at an even lower cost, but the focus for the moment is on the laptop spectrometer.

A concern known as Public Laboratory has  gone a step further to democratize instrumentation (and science in general) by introducing several open source DIY (kits are available too) versions of scientific tools. The hardware and software are both open source designs, which means they are accessible and inexpensive (or free) but are under constant development from the community-so expect relatively rapid changes. The Spectral Workbench software works in your internet browser making it easy to upload data to the spectralworkbench.org site. The data is obtained by scanning samples with the spectrometer your students build. The kit of parts basically consists of commonly available items such as an HD webcam, A conduit box, a piece of black card stock and a segment of an old dvd-r. You can get a .pdf of the build instructions here so take a look.

What is really nice about this process from start to finish is how it integrates the construction and use of the spectrometer to actual science. Your STEM student’s experiments can be used to contribute to the growing database of scanned materials uploaded to the spectralworkbench.org site, helping to identify all sorts of materials by looking at their spectral images. A wide variety of materials have already been categorized, and there are an unlimited number of applications for students to participate through any number different STEM projects, from environmental science to physics.  So we see the collaborative efforts extending  from the creation of these open source products to the students who use them as they share their data online.

The advent of cheap, accurate and easy to use instruments for schools is just beginning. Public Laboratory is currently working on a spectrometer that attaches to your smart phone, which means something very exciting is going to happen before this year’s freshmen graduate high schoool: everyone, everywhere, can soon gather and share data like a real scientist, simply with what they already carry in their pocket.

Click here to view the video on YouTube.

A few years ago, when the Basic Stamp I microcontroller started to gain popularity in schools as the first unprotected pcb that students used, project boxes were not a viable possibility for many teachers. Purchasing a box was expensive, and they were of a generic nature that meant customizing was required, often ruining the look of the box.  At that time the only option for building a custom box or console involved precisely bending sheetmetal and folding over sharp edges, drilling holes and endless frustration to attempt accurate, quality productions that had real utility. And only shop teachers had those tools, which may or may not have been made available to non shop teachers. Some classes resorted to crudely cut acrylic from a benchtop bandsaw, or even cardboard out of desperation to protect valuable electronics . But mostly, the boards were laid out in the open and had their lifespan reduced drastically because of it.

Today, things have changed dramatically in terms of what can be done in an ordinary classroom that can achieve the utility of a custom box that is functional, visually pleasing and most importantly, can be used as an opportunity for education rather than an afterthought. The rising popularity of bare microcontroller boards such as the Arduino and Raspberry Pi in schools as common tools for programming, robotics and the like have made the use of project boxes more critical than ever as students handle and mishandle delicate boards on a regular basis. Bringing all this together with inexpensive design and manufacturing options available in many classrooms means project boxes can be made for just about anything.

The two most common  materials for DIY project boxes are acrylic sheet, ABS (or PLA) plastic and wood. This is because these materials lend themselves to be used by two relatively inexpensive desktop CNC machines that are gaining momentum in STEM classrooms, the laser engraver/cutter and the 3D printer.

Suffice it to say that with these tools there is really no excuse not to enclose your Arduino or other controller boards in a specialized custom project box. The most valuable experience is gained by students who are given the entire task of designing and building their own custom enclosures based on the requirements of projects they are involved with. Free or inexpensive CAD software options are readily available, particularly since students will likely be dealing with 2D or at most 2.5 D parts.  Commercial companies such as Solidworks and Autodesk , as well as open source options from OpenSCAD, TinkerCAD and FreeCAD are good places to start.

If you do not have the time or computer resources to assign students the design of a unique box for their project, there are many available for download on sites such as Thingiverse.com or GrabCAD.com. Another option has recently become available with an online tool called Boxmaker. Boxmaker takes the best of both worlds, with lots customization options in terms of dimensions but very quick and easy file output. It generates PDF files which can then be converted to .dxf or STL  as necessary for some machines. Boxmaker takes the common tab and slot method of interlocking flat sheets together at right angles, and automatically generates each side of the project box. Students simply enter the dimensions and that’s it.

There are a couple of caveats of course, and as with anything that is so convenient to use, there are some things that need to be added in some cases to files generated by Boxmaker. While the parts created by the application will fit together with tabs and slots, this is not a really a permanent or semi-permanent enclosure than can be bounced around without some reinforcement. If possible, look to add a hole at the top and bottom corners for self tapping screws that will allow some flexibility in this area. Just a few screws can make a big difference in the rough and tumble classroom environment. This can be accomplished by editing the line drawing output in a paint program, for instance. Further, if you need cutouts for USB cables and so on, you’ll need to add these in as well. That is no problem if your students just import the files into Google Sketchup for example, then they can quickly add in the additional cutouts. Beyond that, if you want students to use an even more robust system of slotted tab with T-nuts and bolts, it might be best to start with one of the other options mentioned above.

So the time for naked has finally ended with the advent of the new generation of easy to use and inexpensive tools available today. Students can generate useful, customized project boxes for their projects that will make them safe and more durable than ever, while learning valuable skills that add to job readiness as they move forward in your STEM classroom.

So what can it do for you and your students? Gooru ”curates, auto-tags and contextualizes millions of STEM related web resources to get the most out of searches. It ranks and suggests items for students and teachers based on usage data, user input, search query logs and social signals” according to the ONR website. So while it is billed as a search engine, it is much more. Gooru makes STEM video resources available within easy reach of teachers and students in a logically organized fashion. It eliminates lots of search time for relevant multimedia, and keeps it handy for future reference. Gooru users can upload their own videos to help out the community of teachers or for the  use of their own students. And, common core standards are linked to much of the material to make this essential piece of the educational puzzle more palatable to every teacher. Finally, teachers looking to Flip their classrooms have one less excuse not to make this positive step.

As a source of material for students, Gooru excels. Its collections help students keep track of what they have seen, and includes digital texts, games, quizzes and study guides. For students who are used to learning online Gooru is a fun, engaging way to get what they need to be prepared for class on their own time,, with few distractions that might take them off track.

Gooru has combined a many of the best features of several different applications and classroom tools into one service, easily accessible and free. Like all teachers,you are looking for a ways to save time and make your instructional time more efficient,  and Gooru is a good star for the new year.

Student essay are to be between 700 and 1000 words, and are to be in any one of four categories:

• Together, we can feed the world.
• Together, we can build a secure energy future.
• Together, we can protect people and the environment.
• Together, we can be innovative anywhere.

The last option is of particular interest because it is specifically designed to be a broad ranging STEM category.  This rounds out the essay requirements to include students who may not be involved in coursework (or lack interest in) issues covered by first three choices, which focus mainly on sustainability and environmental science issues. This means students in any and all science courses can be included in the contest because it permits essay subjects relevant to any area, from biology and marine science to robotics and engineering. One hint for success: purusing the FAQ reveals that essays are encouraged to be about improvements and positive changes to the world, rather than simply informative.

DuPont give students some resources to start with, with links to helpful videos found here. These should be mandatory research in your classroom to avoid ‘cut and paste’ syndrome we find so often. Student work on an assignment such as this HAS to be original, and every teacher struggles with students who paraphrase the work of others and genuinely believe that makes it their own work. Watching videos without looking at a Wiki can be helpful in this regard, if you follow up with an activity that summarizes what was learned.

Integrating the common core into your STEM classroom just became a bit easier. An essay entry should provide a quality students writing sample as well as meet some of the CCSS as well. So if you have struggled with the added responsibility of writing across the curriculum in your STEM program, fear not: the DuPont Challenge just made it easier, engaging and relevant.

Click here to view the video on YouTube.