Making 3D Printers

Kerrby Day 1 image

Teaching technology has been a blast at Fairhaven Middle School this year. A little coding (we used to call it “programming”), a little 3D design and printing, a little trebuchet and mousetrap car design and building.

I was excited that in the first semester we almost tripled the number of printing hours on the MakerBot 3D printer in the classroom. I have had to order 5 rolls of filament so far (if I recall correctly.) In any case I have not been able to keep up with student demand for 3D printed products.

When visiting the Seamonsters Robotics club at our local high school I saw some home-made 3D printers chugging along making parts for their competition robots. Sehome practical engineering teacher, Kevin Criez, told me they were designed by a local engineer. I found that our local makerspace (Bellingham Foundry) has been working in conjunction with a retired mechanical engineer, Jeff Kerr to produce these printer kits. For $350.00, you get all the parts and free advice and coaching from Jeff and other makerspace enthusiasts and space at The Foundry to assemble your printer.

I have been working on “my” two printers for two evenings so far. Frankly? This has been some of the best fun I have had in ages. I get to build my own 3D printers! Then they go into my classroom and kids will have access to printing on their own. We’ll have a battery of 3 printers (1 Makerbot Replicator II and 2 Kerrby’s – as Jeff’s printers are being called). My goal is to make the design and printing even more accessible by kids.

Right now I receive their files (made in Sketchup) and I export them to .STL format (using a free Sketchup extension). Then Makerbot prints directly from those files. I would like to stop being a bottleneck and have a “PrintMaster” in each class. A student whom I teach to use the printer and respects the technology who can coach other students to preparing and setting up their designs for printing.

This is getting such an enthusiastic response from students that we probably need some kind of after-school time for students to make designs and get them printed.

In the meantime, I am enjoying this at least as much as the students are!



Polished Objects

Build Understanding Logo 3One of the things which I want my students to practice when they are making stuff, whether virtually or tangibly, is the idea that a great design is not epiphany, but is the product of multiple iterations. In other words, making great things requires trial and error.

Valuing mistakes is sort of what this boils down to. We live at a time when we use tools (iPhones), we wear clothes (Nike), and we see (on TV), that the world around us is “fantastic.” Somehow we internalize this to mean that we should do fantastic stuff. What we write, what we make, what we do should be fantastic.

Of course the polished objects we use (Samsung phones, Levi jeans and Toyota cars) everyday are the result of careful research and development. “Development” means that the thing grows (in quality) over time as we “work on it.” We know that cognitively. But minute to minute we expect that WE should not require the development phase. We expect of ourselves that we are so amazing that what comes out of our mouth should be exemplary; what we draw should be brilliant; what we make should exceed all expectations.

But this is not so. Great art (Michelangelo’s “Pieta,” or Frank Lloud Wright’s buildings) requires sweat and tears to make. The product is the result of development. Development takes time.

So back to my students. I want them to learn that: (1) Making great stuff takes effort and time, as you develop your idea; (2) All early efforts are steps toward a better product; (3) Not stopping at the first iteration is the key to making great stuff.

[Images from


Bentley’s Car

jay and Bentley It is probably no surprise that we chose a widely recognized car brand as the name for my son’s car: “Bentley.” Cub Scouts has this event every year and this year Bentley wanted to do the event again. One of the challenges in these events that require a lot of parent involvement is how much should a parent do and what should the child do?

This year I took a page from my science teaching mentor, Chuck Caley from Toledo, Washington. As a new teacher Chuck ran the Science Olympiad program at Toledo after school. He did all kinds of amazing engineering events. Watching him, as a new teacher, I thought he contributed too much to kids’ projects. Mentally I chided him, thinking that his sons would learn more if he did less. It took me several years to learn that my master teacher was right and I was wrong.

When children are given complex tasks to do they often see the objective as insurmountable. A good teacher will scale the task for students so they can achieve a piece at a time. A great teacher will scale the task as well as provide some modeling for students. Chuck was a great teacher (he retired June, 2013.) He did a lot of work with kids and, when they were out of ideas, did a lot of work for kids. But the results speak for themselves. Chuck’s two sons went into computer science. The first went into programming (if I recall correctly) and the second was applying for graduate studies in robotics the last time I talked to them.

These days I do as much as is needed to help capture Bentley’s interest. With the car I cut out the pieces, then we painted it: he painted it. The paint was accidentally an oil based paint that took 2 weeks to dry. After that we used an acrylic spray paint (grey as you can see above.) I painted it for him and he sanded it between coats. I did not know how much this was appropriate, but one day a couple friends came over and I noticed Bentley took them both out on the porch and showed them how he was sanding his car to make it very smooth.

That was a heart squeezer! He did not have the skills and ability to cut out the car on the band saw or to use spray paint to make a smooth coat, but he COULD sand; and he took that task to heart.  I was so proud of him and based on that I saw that we hit the sweet spot on this project.

The day of the race I still had not put the wheels on. I had a plan, but I was ruminating on it and a bit afraid of the risk until, at the 11th hour, I had no choice but to get it done. These wood blanks for Pinewood derby cars have a groove in the bottom for the nail-axles. The problem with that design is that a bit of a knock, like a child dropping a car, causes the axle to mis-align and then the car does not work properly. We had that problem last year.

I decided to bore new axle holes. I think this is against the strict pinewood derby rules, but our program here permits more latitude. So I bored new axle holes about 1/4 inch above out outside the original axle grooves. I used a drill press and got them situated exactly right.

This proved to be an excellent idea. 10 minutes after going to the derby with his car, Bentley runs breathless into my office calling, “Dad! Dad!” Somehow his car had been damaged and one axle was SO bent that the wheel was tight against the side of the car and would not roll. Thankfully our engineered axle holes saved the day! I popped out the bent nail-axle, grabbed a new nail-axle and pounded it back into the hole. Since the holes are drilled, they were still perfectly aligned. So perfectly aligned, that with a little graphite lubricant and weighting it right to the 142 g maximum mass (141.7 g technically) with hot glue and washers, we created a winning vehicle. The winning-est vehicle that afternoon with a streak of wins and no losses. Wow! He even beat cars in dens ahead of him (the Webelos).


New Stuff: Invent to Learn

There are many times we may say “thrilled,” but not as many times that we experience a true thrill. Seeing a Twitter link to a new book i had never heard about before called “Invent to Learn” was an honest thrill!
I DO think the author's should have contacted me to borrow the title of my fallow website “Build Understanding” instead of the more awkward “Invent to Learn,” but then maybe i predict their thesis incorrectly (i have only read the first 5 pages so far). But what i have read puts me on excited pins and needles.
I started my own hacking (small “h”) website in about 2007 while teaching alongside a masterful science teaching artist at Toledo High School in Washington, to fulfill a professional development (PD) requirement for teaching in my state of Washington. It would have more constructive to simply watch my colleague (designer, Science Olympiad guru and Maker 'par excellance:' Chuck Caley) and spend time being mentored by him. (One of the sillinesses of the age of “accountability” in education is that rich opportunities like building things together or talking or watching or sharing coffee in the workshop are not easily measured and so you have to sit in meetings or take “official” college courses in order to “demonstrate authentic growth…” Blah, blah, blah
I was permitted to design my own 8 hour PD and wanted to have a more organized curriculum for the 9th graders in my Physical Science class. Nicely, i could teach whatever i wanted since the curriculum consisted of nothing more than a textbook (“What do i teach?” “Huh? Well i guess just use the textbook…”). But my Western Washington University teacher training (1998) drilled in the fact that teaching is an art in which the text may play little role.
My first year i knew how do labs and write lab reports since i had studied science. I was articulate and clever, but since a person only knows what they have seen, and since i had been taught by many well organized and caring teachers but never – until a solo artist in college: Dr. Ernest Kroeker – by a master teacher, my perspective was painfully limited. I wondered how to keep the kids, and myself from mental dessication by using a committee developed textbook rich in factoids but devoid of narrative and substance.
A coarse, newsprint flyer from a wanna-be teacher support, entrepreneur named Ron who called his stuff TOP Science (didn't they all?) was stuffed in my staff mail slot with all the other weekly junk. Still, sitting on the potty was boring so i grabbed the lot and leafed through it in the quiet of a toilet stall. The sample science activities Ron showed looked very doable, and did not require me to buy expensive equipment (other than string and wooden clothespins.) i ordered a book then another and another; $9.99 each, topically organized.
Ron saved my students by providing meaningful activity designed to lead learners to understand. How much more exciting to tinker, then find tou have a question: why?
  • Why does pulling suddenly on the string break it but pulling slowly does not?
  • Why does simply running a string around a couple wheels make require less force to lift?
  • Why does a plastic bag in a jar stay “stuck” to the inside so stringly when you are pulling it out?

I was seduced by watching kids engage with building electric switches from clothespins. Wouldn't premade switches be easier? … Then i realized “easier” was not motivating, but problem solving and constructing seemed inherently engaging. I started adding construction projects as the capstone of each unit.

MEASUREMENT – Students built 3D “recognizable objrcts” using cylinders, cones, spheres, rectangular prisms and calculated the volume and surface area of the finished product.
ENERGY – Student built Rube Goldberg machines on a concept pliagerized from Science Olympiad (where it is called “Mission Possible”) and were graded on number and kind of energy transfers.
MACHINES – It is a rite of childhood to build a catapult, i thought, until i discovered trebuchets! Students shoot at a target and are assesed on accuracy.
So, seeing “Invent to Learn” excites me that an increasing number of teachers and learners and talking about the value and worth of tinkering and making as an educational activity.
I needed this. After a few years in the trenches with supervisors that alternately loved and dreaded “Jay's projects” i am infused with renewed passion to teach my students by helping them learn through doing what they love: making silly, fun and crazy contraptions!
Thanks Sylvia and Gary! and Ron Marson and Chuck Caley and Brian Brewster (who is my current principle and who is on the “kids seem so engaged and seem to learn so much by building cool stuff!” end of the spectrum. In fact it is Brian's bridge, built as an example to his physics students, pictured in the masthead of this blog.)