Friday, April 11, 2014

How to use Autodesk 123D Catch to Scan an Object

1. You need something that can spin with an object on it like a record player,  a camera and a tripod. You will also need a computer with a web browser that supports WebGL and an internet connection.

2. Make sure to take the exact number of photos specified because 123D Catch only allows you to upload up to 70 photos. Take 30 photos at a 45 degree angle of the object while spinning it. (see picture on the right)
3. Take 20 more photos at a more elevated angle while spinning the object. (see photo on the left)

4. Take 20 more photos at a low angle while spinning the object. (see picture on the right)
5. Upload the photos to Autodesk 123D Catch App.
6. Wait for Autodesk to process the photos.
7. Select and Delete any unwanted objects in the photos.
8. Then Select File>>Download as an STL.
9. Print on your 3-D printer.
Don't worry if your first try doesn't work.  Try again. In my experience,  it works 50% of the time.

Thursday, April 10, 2014

Tips for 123D Catch

We "recently" got an iPad air and have started downloading scanning apps. The one I'm using right now is called 123D Catch a free 3D scanning app from Autodesk. You take multiple pictures at many angles and it puts them all together to make a 3D image. The Styrofoam head I scanned turned out to look a bit like a mask. Still, not bad for a 2nd try(the first was of someones head. It failed). 123D Catch uses photogrametry to work which is using triangulation to find the XYZ coordinates of a voxel.

We also tried using a DLSR take 70 pictures of a Jackel and then turn it into a 3-D model using 123D-Catch. We got a pretty good 3-D model(on the right).

The next time we tried, we used a record player to spin a bird and took 70 pictures at 3 angles. We got a perfect 3-D model!

Thursday, April 3, 2014

3D Scanners - What are the Options?

[This post represents a collaboration between me, the teacher, and a number of my middle school students.  It continues to be a work in progress!]

While CAD is fun, I am keenly interested in students' capturing their own data to work with and print.

So, we looked into a couple of ways we could make this happen:

    1. Photogrammetry is the science of making measurements from photographs - geometric properties (gives texture, and is dynamic). Photogrammetry relies on triangulation (Using triangles to determine the XYZ coordinates of a voxel) to make a 3-D model of an object An example of this is Autodesk 123D Catch which allows you to take about 70 pictures of an 3-D shape
              and make a 3-D model of it.   

    2. Laser line 3D scanning is a non-contact method of capturing the shape of a 3 Dimensional object. It uses a laser and 1 DSLR camera. If  you have the camera the cost can run as low as $20. The laser allows you to use triangulation because it creates a known angle in relation to the camera.

    3. A structured-light 3D scanner is a 3D scanning device for measuring the three-dimensional shape of an object using projected light patterns and a camera system. Good tutorial

    More notes we are working on:
    • utilize a 3D scanner (some DIY models run as low as $300 / higher end models run into the $1000s)
    • Makerbot Digitizer
    • (new) Structure Sensor - a Kickstarter for a mobile scanner for your iPad.
    • (added11.12.13) 3D Systems Sense 3D scanner - just heard about it, need to learn more
    • visit a local makerspace that may allow you to run your own scans on their equipment
    • use a service like Autodesk123DCatch - - where you send in a series of 2D photos (taken in class) and they send back a file with a 3D reconstructed constructed model.

    Time-of-Flight Scanners
    Triangulation Scanners
    Structured-light Scanner
    Stereoscopic Scanner
    Photoscopic Scanner
    Silhouette Scanner

    structured light vs laser CCD
    David Laser Scanner
    CadScan 3D (now called Cubik)

    Other things to watch:

    Open Source CT scanner (cool!)

    Saturday, March 1, 2014

    Air hockey robot made from 3D printer parts!

    Impressive use of spare 3D printer parts!  Read more about the maker, Jose Julio, and his project on his blog.

    It's the little things that save your sanity

    My homegrown makerspace has been a labor of love and has provided its own set of learning experiences.  I've found lots of advice about shopping around for furniture, bins, tools and supplies, but here are two items I also recommend, discovered out of sheer necessity.

    #1 - A small, "cute" tabletop garbage can.

    With 3D printing, you will have little bits of extruded plastic EVERYWHERE.  My middle school students were notorious for leaving scraps laying around, or brushing them onto the floor. Enter one "cute" garbage can.  Now they can't wait to put their scraps in there, and they even like looking inside of it to see their collection of scraps and failed prints grow.  (I can't explain them, I just teach them.) :)  It's also easily portable, and we move it around the room as different tools and 3D printers fall in and out of favor with the group.  I bought this one at Target.

    #2 - A 3D print display stand (ie: a non-slip spice rack)

    The students in my science classes love to handle the 3D printed objects that are left behind in my room.  Often, science students will take a model to their desk and just enjoy having it sit there for the duration of the 50 minute class period.  However, the constant movement was a challenge.  I tried a spot on the table, ziploc bags, buckets and trays, but the models were all over the place.  Until I ordered the spice rack.  Still room for improvement, but it's better.  I plan to order a second one.  Of course you can build your own, but I (embarrassingly) was looking for a cheap, immediate, injection-molded solution.

    PS: We also discovered that an O Organics animal cracker bin (Safeway brand) fits the Cube build plate perfectly to soak off the "Cubestick" glue!

    Friday, February 28, 2014

    We're going to Maker Faire!

    We will be presenting "Black Pine Circle School 3D Prints Data & Designs" at this year's Maker Faire - come join us? :)


    Thursday, February 27, 2014

    #tbt The origins of 3D printing at BPC

    Rep Rap Mendel (Wikipedia)
    It all started at the Maker Faire.  In 2009, I recall standing in front of a table showing off a Rep Rap 3D printer, described as a "self-replicating machine."  Time stood still as I tried to wrap my head around this.  Did it print its own wires?  The metal poles? (It did not, I later found out.)  However, the seed was planted and I was intrigued.
    However, the skill-level needed to assemble a kit and the cost of a pre-assembled machine both seemed like formidable barriers to difficult to overcome.  However, I had some students who believed that anything was possible (especially when they are spending other people's money...).  One student in particular, Adam, was determined to talk me into buying one.  Knowing that our skill level combined was still lacking, I opted to find a way to bring the price down to a reasonable amount.  I began attending all the tech events I could and networking... after all, you never know who you might meet!  I even sprung for some Office Depot-printed business cards. :)

    After a few years of opportunistic networking and Adam's logic as to why we *needed* a 3D printer at school, I attended the NextGen Science Fair in 2011.  Here I met Brook Drumm and he would become instrumental in helping us begin our 3D printing journey.  Brook had his new 3D printer on Kickstarter, with the goal of "a printer in every home (and school)."

    Adam used a page from a classroom book called Geek Logic, which uses algebra to "help" you decide such pressing issues as "Friends or girlfriend?" "Should you walk, bike or drive?" and "Should you eat something scary from the back of the fridge or just order Chinese food again?"  He did the calculations for "Should you buy something or not?" and, as you can see in the illustration below, the answer was 2.912, which was clearly greater than the recommended value of 1.  This only supported his belief that we should buy a 3D printer for the classroom.  Adam even boxed in his answer as instructed in math class!  (My favorite part of this story is that, 2 years later, Adam used his Bar Mitzvah money to buy his own Printrbot, which he assembled from a kit!)

    (2011) Printrbot

    Brook offered us a generous discount to get started and about the same time I was fortunate to win a teaching award, so it seemed everything was in place to purchase our first 3D printer!  Brook even came down with the printer to help set it up and teach us how it worked!  (You can read Printrbot's side of the story here.)

    Watching the video now, I am surprised in how far we have come!  Tinkering requires patience, and students can be better at taking things apart than putting them back together, so soon I wanted a more reliable machine that I the kids would not be able to take apart.  A more reliable machine so that I could have the kids focus more on the CAD design and less on getting the machine to work (though this is a valuable lesson in itself).

    (2013) Makerbot I - Dual Extrusion

    Finally, I purchased a Makerbot Replicator 1 with Dual Extrusion.  (Not that we can get the dual extrusion to work - it's supposedly easy, but we haven't yet successfully printed a merged stl file!)  The first print we made on the Makerbot was a preloaded file from the included SD card.  The first modified design we printed was a pen (see "inspiration" below).  Originally from Thingiverse, one of the then-6th graders was determined to create our own, personalized version.

    This Makerbot (which I paid for out-of-pocket) inspired our first formal BPC 3D printing after school club in the spring of 2013.  Partly to recoup some of the cost of the machine and mostly to have a sandbox environment to experiment, a small group of students and I met weekly and this blog was born! :)

    (2013) Printrbot Jr. v.2 

    After a wonderful summer opportunity involving 3D scanning, modeling and printing at the Advanced Light Source at the Berkeley National Labs, I was excited to learn more with my students during the 2013-2014 school year. Plus, the summer stipend made it more palatable to purchase my classroom's third 3D printer.  This time, going back to our roots, we went with Brook Drumm's newly released Printrbot Jr. v.2, again with a generous discount.  This gave us a chance to work with PLA, especially in light of some recent research about ABS ultra-fine particulate.

    (2013) Cube 2

    We were seemingly set with 3D printers, but who were we to turn down a free Cube printer offered by one of the educational team members at 3D Systems?  We had some trouble with the first one, but 3D Systems quickly replaced it with a fully functioning machine.  We had our share of trouble getting the second one started, too, but after the initial bumps it has been very reliable. This is our first truly proprietary machine, and we've had mixed feelings about that, but it is now the most dependable machine of the bunch.

    I'll let the kids share their opinions...

    "The Cube is best for high-precision parts, or parts you need right away.  The Makerbot is my favorite, because it balances the ease of use with the ability to control it and tinker with it." (Jane, 7th grade)

    [to be added]

    Wednesday, February 19, 2014

    Printed Scan Data: Eggshell

    Today, we finally printed more data from our trip to the Advanced Light Source earlier this year using only open source software.  We ended up with an approximately 5 cm model of an eggshell printed from scan data from an original sample that was a few millimeters long.

    reconstructed data on computer

    Why an eggshell?  Well, here is the abstract from the student group whose experiment involved the eggshell:

    We at the Black Pine Circle Scientific Studies Division, want to scan an eggshell. Pores on the surface of the shell allow air and moisture to go through. A larger, 3D-model will provide tactile information. Designs may be made to create new housing materials, for hot, humid places. We will be beaming hard X-rays through the sample from various angles, giving us a computer model, which can be 3D-printed. This information can be studied for housing materials, to create a new type of ultra-modern house that literally breathes in places with moisture buildup.

    Besides, eggshells are pretty fascinating!  Scientists have known for a long time that the chicken eggshell is 95-97% calcium carbonate crystals, but it wasn't until the electron microscope came around that they discovered, "Rather than simple layers of crystals of calcium carbonate, the shell was shown to consist of a very complex type of mineral formation, with a protein matrix as its foundation."  (journal article, and perhaps way more detail than you will ever need about eggshells!)

    The Exploratorium states succinctly, "Bumpy and grainy in texture, an eggshell is covered with as many as 17,000 tiny pores. Eggshell is made almost entirely of calcium carbonate (CaCO3) crystals. It is a semipermeable membrane, which means that air and moisture can pass through its pores. The shell also has a thin outermost coating called the bloom or cuticle that helps keep out bacteria and dust."

    Another site explains, "The outer cover of the egg, the shell comprises 10-11% of total egg weight. On an average the eggshell weighs 5-6g, with remarkable mechanical properties of breaking strength (>30N) and is 300-350 micrometer thick. This structure plays a crucial role in protecting the contents of the egg from the microbial and physical environment and in controlling the exchange of water and gases.

    More research uncovered these two diagrams, which makes me think that we actually printed the eggshell "upside down" or more-accurately "inside up," revealing those mammillary layer structures that touch the inner, organic membrane! Interesting to consider.

    General egg and eggshell microstructure diagram. (Photo credit: Shaena Montanari)

    Our printed inventory now totals:
    • v.1 beetle bean scan
    • v.1 eggshell scan

    Tuesday, February 18, 2014

    3D Printed NAILS?!

    Wow!  This certainly is something I hadn't considered - 3D printed nail art?!  TheLaserGirls shop on Shapeways offers a variety of 3D options -  $30 gets you your own set!  Created by NYC-based digital artists Sarah C. Awad and Dhemerae Ford, these nails did not originally start out so mainstream - you can see some of their more dramatic designs on their Instagram account or their Tumblr.  They even have some nails printed in brass!

    Read more about the nails and the designers at the personalize blog.

    Wednesday, February 12, 2014

    Converting .tiff data to .stl file

    In December we went to the Advanced Light Source as a field trip. We scanned many items at the synchrotron. One item we scanned was an egg shell. While the image we can see on the screen is cool (right), a model we could touch is better!  We just got multi-image TIFF files as a stack back and, in order to make a model, we needed to turn the stack of 2D images into an STL file to 3D print. We did this using Fiji, and image processing package.

    Here are the steps we took:

    1.You start out by going to FILE >> OPEN. and opening the tiff stack.

    2. Then you create a binary from the tiff stack by going to PROCESS >> BINARY >> MAKE BINARY

    It turns into this

    3. If your model has holes in it that you want to fill you can go to PROCESS >> BINARY >> FILL HOLES.  If your model still has holes then repeat step 3.

    4. If you want to make your file smaller then go to PROCESS >> BINARY >> DILATE it will condense 4 pixels to 1 pixels. If you want it super small keep repeating step 4.

    5. If their are stray pixels then go to PROCESS >> BINARY >> ERODE. If there are still pixels repeat step 5.

    6. Once you complete steps 3-5 you go to PLUGINS >> 3D VIEWER. Don't worry if your computer freezes; this is a complicated process. A new window should come up.

    7. To create the 3D surface you go to EDIT on the new window >> DISPLAY >> SURFACE Don't worry if your computer freezes; this is a complicated process. You should now have a 3D model!

    8. To export you go to FILE >> EXPORT SURFACES >> STL(BINARYorASCII)

    That is how you take an TIFF stack and covert it to an STL. I took the STL file and put into the Cube software but you can do what ever you want. NOTE: MOST PRINTERS CAN ONLY HANDLE FILES LESS THAN 50 MB.  (If your file is too big, you can simplify / decimate it in MeshLab.)

    Finally, here is a print of our first converted data (below): half of a bean that was previously home to a Bean weevil (Callosobruchus maculatus).  That's actual data!  Though this is not a picture of the exact bean we scanned, the image to the right will give you an idea of what the original looked like.  (We are claiming Fair Use on the use of this image!)  We are excited to print more, including the eggshell described above.

    (screenshot of reconstructed data from a different, not open-source software)