Can 3D-Printing and Computer Aided Design be of value in the Contemporary Urban Elementary School Curriculum?

The answer is a definitive YES!

During the past 4 weeks we tested this hypothesis as follows:

MacGyvrBot, a Personal Manufacturing Robot (also known as a table-top 3D-Printer) and Skip Meetze (both affiliated with INTERLOCK) volunteered to be part of the team teaching 4th, 5th and 6th Graders at School No. 52 in the Rochester City School District.  The 4 weeks of Tech Camp ran 3 mornings per week.  Michael Slade (another volunteer) and Susan Reuter (the teacher) rounded out the instructional team, and 20 students developed their skills at rapid prototyping while having fun learning some principles of physics.

America's Cup Toy Boat

The students each constructed an America’s Cup Toy Boat Kit (an STL file for the design can be downloaded at America’s Cup Toy Boat Kit by MacGyvrBot – Thingiverse) with soda straws and parts made on a Printrbot LC (Printrbot LC (v2) | printrbot).  Then they conducted a “shoebox regatta” where the sailboats were each sailed in a plastic shoebox half full of water.  The boats successfully (1) sailed on a reach (with wind from the side) (2) from one end of the box to the other, (3) without touching the side of the box, and (4) under the power of a student gently blowing through a straw from the side of the box.     This activity taught the students the basic principles of sailing while they developed confidence in their new skills of measuring materials (the straws) and assembling rapid prototypes (the boats) as MacGyvrBot chugged out the plastic parts right before their eyes.

Subsequently the students learned some basic skills in CAD using Tinkercad (Tinkercad – Mind to design in minutes) and Sketchup (SketchUp | 3D for Everyone).

At the end of the camp, students evaluated their experience by (anonymously) rating some of the lessons presented.

Student ratings

The Students’ ratings clearly show that using the 3D Printer and CAD are at the top of the list of things they would like to do again.

MacGyverBot in the classroom

A warning about Tinkercad:

There were special work-around requirements that we encountered for safely using the current version of Tinkercad with young students, and they will be further discussed in a later posting.  Tinkercad is resident on the internet cloud and not on the local computer, so continuous adult supervision is required (with an adult logged into the website) for Tinkercad to be safely used by kids (else the child’s access to sharing on the internet will be unsupervised).  Autodesk, the new owner of Tinkercad, is working on eliminating this requirement.

Parents and teachers, stay tuned… 

More about what we learned from participating in the Tech Camp will be discussed in later postings.  One of the neat things about rapid-prototyping in the classroom is the ease with which teachers, parents and designers can share their designs and ideas with each other.

from on August 2nd, 2013Comments0 Comments

Family Friday at RMSC

Interlock brought five demonstrations to our table at the Rochester Museum & Science Center Friday, July 19, 2013.

This was noon to 4 for the Make It! installment of their summer Family Fridays series.

From left to right, we see the MacGyverbot Printrbot LC generously lent for this demonstration but often seen in operation at Interlock, the Interlock Huxley RepRapPro 3D printer, a blue and white lunch-sized slow cooker keeping some Polycaprolactone (PCL) hand-moldable and 3D-printable thermoplastic (previously) warm and ready to try for free-form molding, the shoebox regatta demonstration (with special guest Mr. Jaws!), and at the far edge, a solderless breadboard with a temperature comparator demonstration featuring two LM35 temperature sensors picked up recently from College Home Hardware in Toronto.

Interlock's table at RMSC

Interlock table at RMSC Family Friday

We shared that portion of the first floor with some folks from Greater Rochester Robotics, who brought the robot from their most recent FIRST Robotics Competition season, Ultimate Ascent. They were letting visitors move the robot around the floor and occasionally launch a plastic flying disk or two.

It wasn’t quite the battle of the bots, but a couple of times the ‘bot got up a good head start and whacked into the front of our table, sloshing around the water in the PCL crock and the regatta box. Midway through, such a collision might have had a role to play in loosening up the Huxley’s X-axis drive gear (now since fixed), at which point we switched from printing in silver-gray PLA (polylactic acid) on the Huxley to printing in fluorescent yellow ABS (acrylonitrile/butadiene/styrene) on the MacGyverbot. This led us to discover that kids love them some bright plastic sharks.

GRR robot at RMSC

Greater Rochester Robotic’s 2013 FIRST robot wheels around the first floor of the Rochester Museum & Science Center.

from on July 23rd, 2013Comments0 Comments

11 Digit, 7 Segment Display

An early test result, showing text and millseconds since power-on.

About a year ago, I bought a few 11 digit, 7 segment red LED displays from Active Surplus up on Queen Street in Toronto. (Excellent store.  If you’re into hacking stuff at all, it’s well worth the trip. Look for the monkey on Queen street to find their entrance.)

This past week, I wasn’t sure what to do at Interlock on Tuesday night, but I had recently re-found these displays, so I figured I would finally get them working.  I hit Radio Shack to get a Seeed Studio Arduino Shield ($10 with a mess of components, probably the best deal in all of Radio Shack.)

The display with a header soldered on, and the shield with its assorted parts.

I was all set to figure out how to reverse-engineer the pinout on the bottom of the display; I googled for the LED module, and found specs on those, and then on a whim, decided to check on the entire module board, a Rohm LU-3011, and found the jackpot, this post about figuring out the pinout.  It suddenly became very easy to do this project.

The two key things gleaned from that above post, which I have mirrored here, are this table of enables for each of the 11 digits:

Digit 1 2 3 4 5 6 7 8 9 10 11
Pin 1 2 3 4 6 8 10 12 14 16 18

and this image, showing the pin mappings of the segments:

Mapping of the segments to the pins on the header.

The basic way these displays work is that all of the 7 segments (plus one decimal point) are all tied together to the pins specified above.  Then the anodes for each of the displays are broken out to the pins in the table above.  So to draw a ’7′, you would set all of the segments to LOW, except for pins 11, 19, and 7 which you set HIGH.  Then to turn on a specific digit, let’s say digit 11 (rightmost), you set the digit enable pin 18 to be an output, and set it LOW.  Set all of the other digit enables to be inputs (tri-state, not low or high), and only position 11 will show a “7″.  You repeat this for all of the 11 digits in the display, and you can display 11 full digits from just those 19 pins.

In my code (available below) I start at digit 1, and work down to digit 11, enabling each one, in turn, showing its segments, waiting 1 millisecond, then disable that digit, move on to the next one.

I soldered a pin header on the display, and built up a shield to plug it into.

All of the digit enables wired up.  The top ones are a bit messy. Sorry about that.

I wired it up such that the digit enables and segments are wired directly to IO lines on my Arduino.  This used all of the IO lines, minus the D13 pin, which has an on-board LED.

The code that I wrote (available below) lets you do arbitrary digits per character, so that i can do (primitive) alphanumerics, or do animation patterns, etc.  I also store the decimal point as a separate character going in to the display code, so “3.141″ is five ascii characters going in, but a flag is set on the ’3′ position saying that this digit should also display its decimal point, so it only consumes four digits in the display.

just testing out all of the segments and digits

For now, it displays a nice clock and some animations on my desk, but I plan on changing it around a little in the near future.  I want to use the D13 line as one of the segment enables (probably decimal point) and move the segment enables off of the Serial Receive line.  That way i will be able to control it via serial to display patterns, animations or text content.  Since the hardware serial port is hardwired to 0 and 1, and I will be using the TX line for the LED displays, I’ll have to instead use the Software Serial, with only its Receive line mapped to an IO pin, and its Transmit line mapped to junk. I’ve done this before and it works well.

The code for this project is available in my Geodesic Sphere github repository.

This post is also available on my personal project blog thing.

from on May 17th, 2013Comments0 Comments