3D Printing Demos for Library Workshops

[Dan Henry]

We're having Teen Tech Week here in New Orleans, and as part of my regular library volunteering efforts, I volunteered to do a series of 3D printing demos for the library's Tech Week programming.  I've never done one of these for kids (should be "teens", but I imagine the after school program could include elementary school kids as well).

I would appreciate any advice on curricula outlines, demo tricks, etc. that I could use to fill the hour (may be longer? that I expect to have.

- So far, my plan is to have the printer already printing when they come in.  I figured trying to print after some kind of intro talk might take too long/be too much of a lag in tempo.  

- As they gather around, I'm going to start asking them questions about what they are seeing (Why can't it move faster?   What's making those noises?  What's moving the print head?)  

- After more Q&A - hopefully more Qs from them - I expect the print will end after about 20 mins, and I'll pull it off and pass it around.  

- I'll do another 20 mins starting off asking if anyone's seen 3D printing before (and ask them about that if so), 

- then talking a bit about the history and different types of 3D printing (buildings from quick-dry cement, metal parts being printed on the space station).  

- then if there are more Qs I'll roll with it, otherwise I'll show them the design software for about another 15 mins.

- Then I'll try (if I can find the resources) to let them know where they can go to get more access to 3D printers in New Orleans, 

- Finally, I'll pass out some minecraft tool models I'll have printed out beforehand.

Let me know what you think,

Dan H.

New Orleans

[Chris Fastie]

Hi Dan,

This makes me wonder about what’s really interesting about 3D printing. The fact that a machine makes things out of plastic is not particular new or interesting. The particular way that a machine makes things out of plastic (e.g., extruding molten plastic) is not very new or profound. There are several ways to “print” things in 3D, and new ones are being developed. The fact that a machine can move a tool (extruder) in Cartesian space using x and y rails is not new. There are other more complicated ways to move an extruder. The fact that we can make a 3D model on a computer is not very new – Toy Story was released 20 years ago, and Buzz and Woody were animated!

Although a 3D printer seems like an advanced device, it is astounding how crude the extruder technology is.  A motor pushes plastic filament into a hot metal tube with a tiny nozzle at the other end. If the motor turns faster, more plastic is pushed in and more comes out of the nozzle. Not rocket science.

Maybe the interesting idea about 3D printing is the convergence of a few things:

1.       We all have computers capable of running software that allows us to design 3D models with just a little practice. These models define every point of a model with great (infinite?) precision.  Few of us ever exploit the processing power of our computers (unless we play video games), so it is nice to find a use for all that power.
   
2.        Very cheap processors are powerful (fast) enough to run a machine that coordinates several processes (dynamic temperature control at the hot end, x-axis position, y-axis position, filament feed rate, plus simpler ones like z position, fan speed, build plate temperature, LCD display, etc).
   
3.        Software (slicers) can translate our (infinitely precise)  computer 3D models into instructions so a particular machine will put the correct amount of plastic at the proper temperature at the exact place and do that for millions of places without stopping or making very many mistakes.
   

All three of those things are about computers. Advances in computing allow old mechanical technology to squirt plastic where we want it. And you can have it all for as little as $500.

The more important questions might be Why would anyone pay $500 to $5000 to have one of these machines in their house? A lot of sales of 3D printers must be driven by the cool-new-gadget phenomenon. Although moving an extruder on x and y rails is not rocket science, watching an extruder print is fascinating. Seeing a freshly finished part waiting for you on the build plate is hugely entertaining. Until you realize that it’s just another plastic doodah.

There are some legitimate applications of 3D printing in industry, and probably some for the home as well. Maybe the exciting part is knowing that there are applications out there that no one has exploited yet. There must be something useful and important we can do with these new machines. Maybe we will be the first to think of one of them.

In the meantime, there are probably lots of great educational lessons based on 3D printing:

Cartesian geometry

1. What do you need to know to make the extruder move diagonally?
   
2. What do you have to do to make the extruder move along a curve?
   
3. How are vectors used in a 3D modeling program?
   

Computer programming

1. How does a computer 3D model define a shape?
   
2. What does slicing software have to do (and how can it do all that in just a few seconds)?
   

Computer hardware

1. How many operations per second are required to run a 3D printer?
   
2. What part of a 3D printer is an example of a feedback loop?
   

Robotics

1. How is a 3D printer an example of sensing and control?
   
2. How smart is a 3D printer?
   
3. Does it have artificial intelligence?
   
4. Or is it just a machine doing a repetitive task?
   
5. Does the 3D printer know where its extruder is?
   
6. Or does it know only the vector for its next move?
   
7. Or does it not even know what a vector is?
   
8. How is a stepper motor different from a servo?
   

Electronics

1. How does a thermocouple work?
   
2. What’s the difference between a thermistor and a thermocouple?
   
3. How is the build plate heated?
   

I don’t know the answer to most of these questions so I am not going to get anywhere near a high school class with a 3D printer.  But if I did I would be printing the ratchet wrench that was printed on the International Space Station: http://nasa3d.arc.nasa.gov/detail/wrench-mis. I tried this and the ratchet actually works. I also printed a set of sockets (http://www.thingiverse.com/thing:91496) using files from the Customizer at Thingiverse. They fit the ratchet perfectly. Very cool doodah.

Chris

[Dan Henry]

Chris,

Point taken - after all my first original 3D printed design will be a replacement for the plastic button on a 50s era cabinet latch that we inadvertently melted when restoring our house.  I've never had much use for any of the items typically displayed in 3D printer ads, and I wish they would show more practical products.

Watch this space for my "Mr. Fix it" home-based 3D printer business.

I may be underestimating the audience, but I was shooting more for critical thinking about the things around us, and how they work, and that they are reducible to understandable components. I may also have underestimated the level of interest in the more technical aspects and the arc of industrial/social history. 

I also have only 1 hour and 1 session to work with, so cartesian geometry wasn't my first go-to. ;-)

I'll inject some higher-order concepts and link back to the Arduino/software convergence - like those for an intro session. I may need to wait til next time to print that wrench.  I really like your outline as fodder for a curriculum for a long-form recurring workshop or course.  Since I have no teaching experience outside of mentoring my staff on technical teams, I need lots of help thinking about that.  Not that I have an opportunity to deliver such workshops, but I would like to.

Stratasys has free curriculum that is more the scope of what you posit. I also took a look at it - It's posted on their website here :

http://www.stratasys.com/industries/education/educators/curriculum/introduction-to-3d-printing

I wonder what folks here think of it.

Cheers,

Dan H.

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[Chris Fastie]

Wow, that Stratasys curriculum is huge. I looked at the first few Powerpoints. They are very glossy and more like marketing materials than curriculum materials. The first Powerpoint makes the points:

1. People once had to make their own things (arrowheads, etc). 
2. Then the industrial revolution allowed machines to make things for everybody, but that led to factories and material and product transportation which are wasteful and harmful. 
3. The current industrial revolution will allow people to make their own things again. Factories and transportation will no longer cause us so much harm.
   

Utter nonsense.

Subsequent Powerpoints were textbooky outlines that mostly defined terms. They will be very useful if I want to help someone learn the difference between FDM and SLA.

Next Powerpoint -- What is a mesh?  Or I could use Wikipedia.

I'm still curious about why it is so much fun to watch a 3D printer print. That juicy plastic keeps oozing out at just the right place. It makes me think about the mostly invisible process of translating my ideas into CAD designs and then into a mesh and then into instructions that a dumb machine can carry out. What parts of that process are most interesting? What parts are hardest to accomplish? Who should I thank for the most interesting and difficult advances that make it all possible? 

The 3D printer itself produces much less wonder. That is just a source of endless troubleshooting and tinkering to make it work properly. Machines are fun, but it's not about machines, they have been around a long time. It's about the process. So asking kids to extrude icing to make a shape seems to miss the point for me. I would ask kids to sit down and watch the printer for a few minutes. They will immediately see exactly how it extrudes stuff to build an object. And they will appreciate the level of precision and relentlessness needed to do it.

To illustrate the entire process, I might print the ratchet wrench in advance and also a few sockets of different sizes, but missing one size in the middle of the range. I would ask students to measure the sockets and determine the parameters needed for the missing socket, then enter those into the Customizer app at Thingiverse which will produce a custom stl file. You can quickly slice that file and start a print which takes only 10 minutes. The class can see the whole process of identifying a need, making a custom design, translating it for your machine, and printing the object. Then they can use it to tighten a nut on the printer.

Chris

[Dan Henry]

Love your suggestion for the missing socket exercise.  I won't have time for today's session, but I can do the printing tonight for tomorrow's.

[Dan Henry]

By the way, I found out (finally) the format.  I will basically be set up like a grocery store cracker spread demo person.  No one is scheduled to come, just whoever happens to be in the library or saw the flyer/online event.

I was told to expect stragglers and people popping in and out. I hope I can corral a couple of kids into the design/printing exploration, but even that might be a stretch.

If PL is OK with me using the gear some more, I'm going to propose a more ongoing event (or perhaps a formal set of classes with a curriculum) and see if they bite.  

If anyone is aware of funding/grant opportunities for materials (ABS/PLA/acetone/tape/etc.) for this kind of educational program please let me know.

Cheers,

Dan H.

[Chris Fastie]

That format sounds like fun. If you are going to be the cheese spread person maybe squeeze cheese and crackers would be the perfect thing after all. For a more formal class I was thinking that a better way to use the ratchet for a demonstration might be to have something with a bolt that you want to tighten and have the students measure that bolt to get the parameters for the Thingiverse Customizer. Also, the NASA ratchet only tightens bolts -- the ratchet is not reversible. A few people have made a mirror image model that loosens: http://www.thingiverse.com/search?q=nasa+ratchet&sa=.

 

I hope your session was fun,

Chris

[Liz Barry]

Hey Dan, 

Great thread. 

Will you be introducing teens to the idea of using 3d printing to print environmental research tools like what Chris makes, or anything about Public Lab?

PS Chris, i love your utter dismissal of the Stratasys powerpoint intro that was styled as a history of making things in three numbered points. 

and this is such a quotable FIESTA line: "Advances in computing allow old mechanical technology to squirt plastic where we want it."

Lizzz

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[Dan Henry]

Lizz,
I open each session with a summary of what public labs is and what we do, and that thr 3D printer is there thanks to PL.

The sessions are are over now.

I talk a bit about science applications (printing on the space station) but nothing specific to environment. I think it's a great idea and would love to work up a couple quick case studies to introduce PL projects for future demo opportunities.

That with a longer form workshop curriculum would be a worthy project.

Cheers,