make and take, physics

LED Color Mixer – Make and Take

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Tomorrow, Saturday 10/4/14, is the fall meeting of the Michigan Section of the American Association of Physics Teachers. If you’re interested, it will be at the University of Michigan, Flint. For more information you should check out the meeting page.

Anyway, Jim Gell and I will be running a Make and Take in the afternoon. One of the things we will be doing again is the ever popular LED Color Mixer. We’ve done this before as a modified version of the LED mixer presented by Chris Chiaverina in the Physics Teacher. This is a pretty cheap demo device, but in the past we ordered $1-2 LED, $1 battery holder, $0.50 ping pong ball, and 2 AA batteries. Cost for each one was between $3 and $4. This was a bit costly to run as a Make and Take. It also involved soldering, which while not particularly difficult did require the direct supervision of someone.
We will be doing the same project on Saturday at a cost of less than $0.20/device with no soldering required. This project is cheap enough that you can have participants make one on site and then send them home with a couple extras to make with their classes. They’re so cheap that a teacher could have each of their students make one to take them home and explain how they work to their families.

The parts list:

I should note that while both the batteries and LEDs are sourced from Amazon, the LEDs come from China and will take a few weeks to arrive. While the LEDs are cheaper than we’ve been able to get them in the past the real savings is from the batteries. In order to make things extra cheap I replaced the ping pong ball with a paper cube.
Simply bend the leads on the LED as shown. The shorter of the two leads goes to the negative side of the battery with the longer going to the positive. Use a little electrical tape to hold the leads to the battery. If needed, slip a small strip of overhead transparency in between one lead and the battery to act as an “off switch”.
Print out a copy of the 2.25″ Cube Template and assemble. Before closing the last flap put 1/2 a Kleenex in to help diffuse the light and cut a hole in one side. The simply slip your LED and battery in and bask in the color changing goodness you have created.
How would you use this with your students? Share your thoughts in the comments.
3dprinter, makerbot

Getting Started with 3D Printing – Part 1

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I’ve had a 3D printer in my classroom for a couple of years now and it is totally awesome. Last year I wrote a blogpost answering a question I received as a tweet. The question was, “What resources or designs do you wish existed for teachers/students when you got your printer?” I’ve decided to do a series of posts from an educator’s point of view to create the resource I wish I’d had when I first got my 3D printer.

There are a lot of emerging technologies that are capturing attention today. Of all of these, I think 3D printing has the most power to inspire students. I managed to get the first generation MakerBot Replicator a couple years ago and every time it’s running in the back of my classroom it acts as a student magnet. Some would just stand and watch a print run from start to finish if I’d let them. I have to say it is pretty awesome to watch an object get made seemingly out of nothingness.

When I got my printer, it cost just under $2,000. Today you can get a pretty respectable machine for under $500 and if you want to go into the $2,000 to $3,000 range you can get a really nice printer. If you’re in the market for one I would highly recommend picking up a copy of Make: Ultimate Guide to 3D Printing. The last two years Make Magazine has done a great rundown on the consumer grade 3D printers that are available. If I was going to buy a new printer, this is where I’d start.

The main thing you need to know, is there are two broad categories of 3D printers you might consider for your classroom, Fused Deposition Modeling (FDM) and Stereolithography (SL). My printer does FDM so that’s what I’m familiar with and able to speak to. I really want to try SL, because it’s totally cool. The most common printers in classrooms today use FDM, but this may change in the future.

In a nutshell, Fused Deposition Modeling printers melt plastic and push it out through a nozzle like a hot glue gun. The nozzle in this case is much smaller and hotter than a glue gun, however. The printer builds the object up one layer at a time.

Stereolithography printers use a liquid resin. The resin solidifies when a light is shined on it. These printers also build an object one layer at a time, but the do so a bit differently. The light source in an SL printer will either be a laser that traces a path similar to an FDM printer or a DLP projector that will simply project an image of the whole layer at one time. Once the layer at the top of the liquid solidifies, the printer lifts the growing object and the next layer is illuminated.

If you’re looking for more resources to get you started I’d recommend:

Continue to Part 2 in the series.

3dprinter, makerbot, openscad, tinkercad

A question about 3D printers in education

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I was recently asked a question about my 3D printer:
This ended up being very thought provoking on multiple levels and as with all thoughts I have like this I thought I’d share them here.
Through serendipity about a year and a half ago I found I had unspent grant money that needed to be spent. As I’d made a few big rounds of purchasing for my classroom lately I felt I pretty well supplied. So I decided to take my largess and spend it on a Makerbot Replicator. I entered into this technology purchase in the worst possible way. Here was a big tech purchase and I really had no specific educational outcomes in mind and yet with a tool with the promise of this one I feel no regrets on that score.
So, back to the question. What resources do I wish I’d had? I wasn’t quite sure what Matt meant and I’ve decided to not ask for clarification on this question, but to answer it a few different ways. A few of these wishes have since been met, I’ll point out the resources where appropriate. I’ll also add in the resources I’m glad I had.
What resources do I wish I had before I purchased my 3D printer? 
I wished I had a good breakdown of all the entry level 3D Printers available on the market created by a third party (that is to say, not marketing material for any one printer). Personally I spent a lot of time on the internet searching before finally settling on Makerbot. Now, of course, there is the Make: Ultimate Guide to 3D Printing and they’re now working on an update to this guide. I’d add that I’d like to see one of these done by educators to see what they’d predict they’d see in a school environment with the different machines. This team should include some dedicated industrial ed teachers as well as core content teachers who might use 3D printed objects in their curricula.
Another thing I would like to see is some sort of article or set of articles that could be used to justify the expense of such a machine in the classroom. These could be used to help sway a school’s administration into investing in such a device. Inspired by the question I will try to create such an article in a future post.
Now, once I had my printer what resources do I wish I had?
First on this list would be easy to use software to run my 3D printer. For those not familiar with 3D printers, you need a piece of software that will take the 3D model file to create the tool paths for the machine to follow. This one has been solved for the Makerbot with Makerware. I’m not sure if Makerware will work with other 3D printers or not. Makerware offers very easy default options, but also gives the more advanced user more control. These advanced features are mostly hidden from novice users which really is a good idea. With the advent of Makerware my Makerbot became much easier to use and more versitile.
Next on this list would be an easy to use CAD program. I teach physics and electronics with micro-controllers. Neither of which have much time built in that could be used to teach CAD (even Sketchup). This problem has also been solved for me in a couple of ways. The first of these is a service called TinkerCad. TinkerCad runs in the cloud and requires no software install (always a bonus in schools). It allows you to easily create 3D models and export them as *.stl files ready for printing. Note, there are actually lots of options now. TinkerCad is my favorite though.
Another option that occurred to me last year was OpenSCAD. OpenSCAD allows you to create 3D models programatically. This is not something I plan to teach to my physics students, however. The power here is that like any program you have variables. So you can create or find a good model and then let students explore how changing variables can change the underlying model. My students were able to investigate how changing the parameters of a wind turbine affected the output voltage while possessing no 3D modeling skills. We created and tested 20 different designs. The designs were all created in only two class periods, one each for my two sections.

I would also have liked more nuts and bolts advice and knowledge on operating my printer and the problems I might encounter. To some degree it really is impossible to put together a resource that covers all the potential pitfalls, but I had to fumble around quite a bit. The biggest issue I had to overcome was the warping of parts. This happens for particularly large parts as they cool. The can pull away from the build platform and distort the part or even come loose ruining the print run. The “Helper Discs” that appeared in the example menu in Makerware have helped me immensely with this problem. While there is some overlap, the needs of a Maker are often much different than the needs of a teacher.
The final thing I wished I had when I got my 3D printer was a good idea of how to leverage the power of this device to enhance my teaching. I know it’s a bit ironic, this is exactly what I said I didn’t have and didn’t really care about when I started this post. What I’m still looking for are really cool design projects I can use with my students to tie together what we’re learning with real world applications and critical thinking. To some degree this has been solved a bit with the Makerbot Curriculum page, but I’m still not satisfied here. Now that I’ve discovered the power of OpenSCAD, a whole range of potential projects has become available as well.

Bottom Line?
Some of the things I wished I had are now available but a few are still lacking and might never really exist:

  • Breakdown of best 3D printer in an educational environment. Ideally created by educators (and their students)
  • Articles to be used to support an educator in the purchase of a 3D printer.
  • Cool design project ideas to be used in conjunction with core content classes.
  • Nuts and Bolts guide for teachers on how to use and trouble shoot problems.
3dprinter, physics

Fun with a 3D Printer – Physics Wind Turbine Project

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Almost a year ago I managed to find money to buy a Makerbot Replicator for my classroom. It really is like magic. Most of the year we’ve really just been playing. Printing out cool stuff from the Thingiverse and a few project enclosures for electronics projects.

I’d been wanting to do a cool design project with my physics students, but never really knew what it should be. 3D design is not a skill in the wheelhouse of virtually any of my students (our CAD program died a few years ago). It turns out there is a cool program that lets you create 3D designs programmatically. It’s called OpenSCAD. The beauty of this is that you can create or find a program that generates the 3D design. Then all you need to do is change some of the variables to get a new design.
I decided to give this a try in my physics classroom. We’re in the time of year after the seniors are gone and now the juniors feel like they should be gone as well. I found a cool Mini-Wind Turbine model on the Thingiverse that was created in OpenSCAD. I played with it a bit to figure out exactly what the variables did and then introduced it to the class. Next year I’ll let them figure out what each of the variables does for themselves.
Each of my two physics classes picked two parameters to vary. We ended up with:
  • Length
  • Width
  • Angle – Which was really twist
  • “Fat Point” – Ratio of top length to bottom length
We created 5 different versions varying our on parameter. I let the students decide what they wanted to set the parameters to as long as the blade was not absurd.
Actually we did end up with an absurd blade when it came to twist, but the group that wanted it were convinced it would be the best. So I went ahead with it.
I asked students to graph and find the relationship for each of our four parameters. Unfortunately none of the parameters gave us very good mathematical relationships. I think we might have needed bigger variation in some and more data points in between in another. Next year I may have students fill in some of the gaps.
Once data were analyzed I asked them to design the perfect wind turbine. Some groups relied on their data and some did not. It should really come as no surprise that the groups that relied on the data did the best. Of these most just picked the one best data point in each and put them together. The very best one extrapolated from their data to predict a better solution. It’s nice when things work out the way the should like that.
The best part for me was how surprising our results were. We all had the image of the big majestic wind turbines in our heads. This, however, was not the shape that we found to be the best. The one we found to be the best looked the least like our pre-conceived notion. It had fat stubby wings rather than long and thin.
Some nuts and bolts details:
  • 3D Pinter costs $2000ish
  • Plastic is fairly cheap. If I had to estimate, I used between $10 and $20 worth of plastic on this project.
  • One full set of 15 blades (3 each of five different states) takes between 3 and 4 hours to print. One set all by itself  40 min to an hour. Time varied depending on the design.
iBooks

iBooks Hackathon

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I’ve already written a bit about iBooks Author and how awesome it is for creating resources to share with your students. I know some of you are probably rolling your eyes about now and thinking something along the lines of, “More iPads in education… When will this fad die?” Whether or not iPads in the classroom are a fad or not is really immaterial at this point. Like it or not, many schools are already or will be going one to one with them. So we should probably find the best way to use this technology to support our students.

Last year Dan Spencer put me in contact with Tony DiLaura. Tony is an educator from Zeeland Michigan. He is also excited about the potential impact of teacher created textbooks using iBooks Author. His goal is to bring educators together to collaboratively create resources that can be used to make the creation of these books easier. After some discussion the idea of the iBooks Hackathon was born.

We will officially kickoff the Hackathon at this year’s MACUL conference. Then in June we will have two workshops, one on the east side of Michigan and the other on the west side. At these workshops we hope to bring educators together into groups and begin working on cool resources. Throughout the summer these groups will continue to work and in August we will take what has been created to that point and have the official launch of what will hopefully be a large collection of resources for other educators to use.

if you are interested in participating you can check out our Google+ Community as well as our page in the MI-Learning section of MACUL’s website.

physics

GeoGebra and iBooks?

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If you follow my blog you know I’m a big fan of  the new iBooks and iBooks Author. What I wanted to mention today is a cool tool called GeoGebra.

“GeoGebra is free and multi-platform dynamic mathematics software for all levels of education that joins geometry, algebra, tables, graphing, statistics and calculus in one easy-to-use package. It has received several educational software awards in Europe and the USA.”

 It’s pretty cool. After playing with it a little I see some real potential here not only for math, but also science. Below is an interactive I made after playing for only a few minutes. It models a position time graph for an object moving with a constant velocity. You can change the Velocity or the Starting Position (xo).

It literally took me no more than ten minutes to make this having never worked with GeoGebra before. Anyway I was looking at GeoGebra as a way of creating interactive content for iBooks. Anthony DiLaura (@anthonydilaura) has been doing this already. He uses Tumult Hype to take GeoGebra output and get it into a widget for embedding in iBooks. I’ve come up with a slightly different way and easier way, but Anthony’s way is better in some ways.

In order to put your GeoGebra Content into iBooks Author you must:

  1. Download a Beta Version of GeoGebra (4.2 or 5.0) and create your interactive
  2. File->Export as “Dynamic Worksheet as Webpage (html)”
  3. Click on the “Export as Webpage” Button
  4. Click on Advanced (near the center of the window)
  5. Set width to 820 and height to 520
  6. Place a checkmark in the Export to HTML5 box
  7. Then Export. Save as index.html somewhere you can find it
  8. Download my sample widget and unzip.
  9. Replace my index.html with your index.html
  10. Rename the sample folder to: your name.wdgt (Adding the wdgt will turn the folder into a widget file. You can access the individual files again by right clicking on the widget file and selecting “Show Package Contents”)
  11. Embed your widget in iBooks!

I should note one thing. This method will only work if you have an internet connection to the iPad when you’re using it. I have been a bit daunted when it comes to making offline widgets. Check out this discussion forum if you want to try to create widgets for offline use.

There is a lot of potential in GeoGebra. Not just for me as an educator to make interactive elements for my students, but for my students to create them as well. I really wish I discovered this at the beginning of summer rather than the end…

iBooks

iBooks Author Teacher Academy

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This summer it looks like I will be helping run an iBooks Teacher Academy for teachers in my school. We’ll be partnering with a local university (more on this later) so we’ll be able to offer SB-CEUs and/or university credit. Our plan is to use this to help leverage the technology we already have in our building. Last summer we bought a cart of iPads and for the most part we’ve only been using them as a portal to the internet. When we bought the cart we knew this would be the primary way it was utilized, but now we’re hoping to move beyond this.

Our secret plan is to get teachers investing in professional development to change the way they think about teaching with technology. Our summer training will only be three four hour days. The focus of the workshop will be split between how to use programs to author interactive iBooks and TPACK (when did this change? I thought it was TPCK). We don’t simply want to show teachers how to use the tools. We want to help them think about how to use the tools to teach better.

So how will we accomplish this in 12 hours? The short answer is we won’t. We’re also planning a series of three to four more 90 minute meetings during the following school year. These will be a chance to get back together and share what we’ve been working on and get feedback. I’m also planning on pushing for an online collaborative component. I’ve run some staff training in the past and I’ve not gotten much traction with any online stuff I’ve done after the fact, so I’m not dead set on including this. I will be thinking about it through and I’ll post details to my blog if anyone is interested on following our progress.

So, why iBooks Author? Because it is really slick. Yes, I know you’re locked into the Apple iPad ecosystem. But, at it turns out that’s ok at thins point. That said I’ll be watching for Inkling Habitat when it becomes available to the public “later this year”. Our focus is not only on the specific tool, but how we can use the tool to create pedagogically appropriate content for our students. This last is what I’m excited about.

Below is a my latest iBooks 2.0 demo video. I made it in part to advertise the possibilities to our staff while at the same time testing out the capabilities of Camtasia Mac 2 and Reflection (which lets me mirror my iPad on my computer). I highly recommend both programs!

cheap tech tool

Wiimote CPR Trainer?

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Wow, this is really cool. Some smart people (Senior engineering students at Univ. of Alabama) out there have written a program to use the accelerometer in a Wiimote to help train people to do CPR correctly. The program is not available yet, but should be on the American Heart Association webstie in early fall 2009.

What makes this really cool is that it is a perfect example of an inquiry based project. While it was developed by seniors in college it could probably have been done by high school students. The skills needed to create this would be within the grasp of students I’ve had. It makes me wonder what other problems could be solved with the accelerometer in a wiimote…

For those interested in cool applications of Wii technology:

cross posted from FlosSceince

arduino, electronics

Arduino in High School Electronics

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I started using Arduino, an open source electronics platform in my one semester electronics course. Arduino incorporates a microcontroller (mini computer) and allows for a lot of really cool options. Last semester was the first semester I used Arduino with the whole class. It went fairly well.

All students were required to create a final project. I gave them the option of working with a partner with the caveat that when they presented their final project I would get to decided which of the two of them would have to answer my questions.

Their projects included not only the circuitry and programming, but students also had to physically build the device. This ended up being a really good project. Even if they chose to build upon a project they found on the net they had to tinker with it to make it do what they wanted it to do.

Once completed, students had to write up and present their projects on Google Sites. If you’re interested you can go to the class site to find descriptions, pictures and Arduino code. Below is a video created by a pair of my students who used an old remote controlled car as the chassis for an autonomous Arduino controlled robot.


Crossposted from FlosScience

arduino, electronics, processing

Arduino – eeePC Nightmare!!!

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So, I decided to totally change the way I teach my electronics class. It will now center around the Arduino microcontroller, a platform that uses an Atmel ATmega 64/128 microcontorller. Anyway, I don’t really have enough laptops to go around, so I scrounged some funds together and bought two of the Asus eeePC 2G Surfs. I figured these would be just about perfect.

Problem #1: Java, which is needed for Arduino doesn’t come on the 2G Surf. So, after searching for a way to get it on the 2G Surf for a few hours I find it. It installs and all is good.

Problem #2: To really make the Arduino sing I also need Processing. Unfortunately there’s not enough room left to fit it.

Problem #3: After a bit more searching I find a way to delete stuff I’m never going to need (like Chinese language support) from the eeePC. Unfortunately this makes no space available to me.

Apparently there are two main partitions on the eeePC. One for the user to do whatever they want and one that the user really can’t touch. All the programs come installed in the one the user really can’t touch.

Solution? After maybe 10 hours yesterday and another 7 hours today I think I may have this licked. I’ll write up process and post it to FLOSScience for those interested. If I’m right I should be able to capture am image of my one working one and put it on the other one. This would take less than 5 minutes, otherwise I’ll be looking at at least another 2-3 hours to get the other one set.

Better Solution? Get the 4G version ($50 more).