Monday, April 22, 2013

Thing-O-Matic Mania!

In a massively generous act, a friend's employer gave me a mostly assembled Thing-O-Matic 3D printer back in December!


Purchased as a kit, he had got it about 90% of the way there. Everything was assembled, but I had to clean up some of the electronics, adjust the belts, and troubleshoot what ended up being a bad motherboard. MakerBot was very helpful in testing the hardware for me and identifying the bad motherboard and arranging for me to replace it.

I started by printing a variety of test objects to get the belts properly tensioned.


I finally got it dialed-in enough to print a filament spool holder so I did not have a big loose spool of filament feeding the printer.


The filament spool holder and guide works wonderfully.



The tapered pocket coin-op model is fun to print and hand out to people to show them the power of 3D printing.


Once I had the Thing-o-Matic printing well under firmware 3.5 I upgraded to the Sailfish firmware. I tested accelerated printing using a great second century Indian lion model.


The silicon peg on my son's Tommee Tippee bib tore. I printed a replacement that I designed using AutoDesk's 123D Design online application. The model was a featured design.


The holder for the louvered blinds on my back door broke. One lost a peg, the other was completely broken. I used the calipers to take measurements. Then I used SketchUp to build a model and iterate on it until I had a good replacement.


Now the blinds can be secured to the door.


Finally, I let third and fifth graders know about the printcraft.org Minecraft server, where they can build and have a stl model generated. I told them I would print their designs. There were a few students who took me up on the offer.


It has been a very interesting learning process getting the printer up and running. It is exciting to be part of this new technology and makers revolution.

Tuesday, January 15, 2013

TurtleArt: Islamic Tiles

In conjunction with fourth grade art we are going to use TurtleArt to create Islamic-inspired tiles.



We are focusing on making geometric tiles.

Start by creating a procedure that makes the turtle draw a geometric shape. It could be a square, a hexagon, or even an octagon! Use the diamond shaped block under "My Blocks" to name your procedure. I named my hexagon shape "hex."


Next, we need to make a procedure to make the turtle draw a horizontal row of your shape. We use the setxy block to move the turtle around.

Call the procedure that moves the turtle from left to right across the screen "horiz."


In the example above the turtle draws the hexagon shape, moves right 135 steps but does not move on the y axis, then draws another hexagon, repeating until it has drawn 5 hexagons. In this example the hexagon is overlapping the previous hexagon. You might have to experiment with the "x cor + number" combination with your geometric shape.

Now we need a procedure to move the turtle down along the y axis so it can draw its next "horiz" row. Call this procedure "vert."


Depending upon how large your geometric shape is you will need to customize three parts of the "vert" procedure above. First, you may have to repeat more than three times. Second, you will need to customize the "setxy" x values for your figure. Additionally, you will need to customize the "ycor - number" to fit your shape. Play around with the numbers until you are happy with the amount of overlap. The overlapping of the geometric shape and the resulting shapes this creates is part of the beauty of Islamic tile art.


Finally, you need a procedure to make the turtle draw the completed tiles. As you can see in the detail above this turtle is drawing the design twice, once with a wide blue pen and the second time with a slightly narrower grey pen.


The "tile" procedure starts by clearing the screen. It then sets the pen size and color. It moves the turtle to the far top left of the screen (actually, the turtle is off the screen with these settings). It then runs the "horiz" procedure to get the horizontal row, then the "vert" procedure to move the turtle down the screen. The turtle repeats this process with the smaller pen and different color.

Experiment with the code shared here to create tiles. Try using even larger brushes to create more interesting effects. The example below runs the "horiz" and "vert" procedures three times with increasingly smaller brushes.

MaKey MaKey Scratch Operation Game

I have been designing an Operation-type board game that uses the MaKey MaKey to interface with a computer running Scratch.

I started with a simple prototype left over from my squishy circuit Operation game. I was curious whether the MaKey MaKey would read a closed circuit on this hardware. Good news: it works! Connect an alligator clip cable from the MaKey MaKey to the game board's foil "game port." Connect the MaKey MaKey board's Earth port to another alligator clip cable.




I wrote a simple Scratch program that looks for the space bar to be pressed. If the circuit is closed via the MaKey MaKey the cat turns green and makes a sound to indicate that you touched the foil. The prototype worked! The MaKey MaKey recognized the closed circuit!

I made a set of chopsticks to use with the game. You can purchase chopsticks in bulk from Amazon.



I stripped the ends of two pieces of telephone wire. I wrapped each chopstick in a length of telephone wire then covered the bottom of the chopstick in lengths of half inch copper tape.


I ended up removing the electrician's tape in the iteration above and replacing it with a blob of hot glue.

Satisfied that the software and hardware would work I started making a better version of the game.


I started with a MacBook Pro box. I painted it white with acrylic paint. Using an LCD projector, I traced a copy of Scratch the cat onto the box using a pencil.




Afterwards I painted the cat with acrylic paint.




The bottom of the box was a bit too deep so I built a false bottom. I cut some ribs to put under the false bottom and hot glued them in place.




The false bottom was glued to the tops of the ribs.




I traced Scratch the cat with a Sharpie marker.




I used Sugru to make bones and organs for Scratch the cat. The player has to remove these from the patient without touching the sides.




Next, I cut out holes for the bones and organs. It was difficult cutting up my nicely painted cat!




Next, I used cardboard to build little forms to keep the pieces from wandering away from the holes through which the player removes them.




Here are the game pieces in place with the lid closed.




I used half inch copper tape to line the edges of the holes. I also used a piece of telephone wire with the insulation stripped off under each of the pieces of copper tape.




I built storage areas for the game pieces and the chopsticks.




The wires from the holes in the board are routed out the side. Everything maps to the space bar through the MaKey MaKey, so I just clip an alligator clip onto the bundle of wires, the ends of which I stripped of insulation.




With everything in place the game can be connected to the MaKey MaKey and along with the laptop running Scratch and my project, one can play Operation!




I tested it with my fifth grade students. We all agreed that the bones and organs were too large and too difficult to remove without triggering Scratch to remove health points, turn the cat green, and make a sound. I made some smaller bones and organs with Sugru.




The fifth graders are now building smaller-scale versions of Operation games using repurposed cereal boxes. Some used an LCD projector to trace their image. Others free-hand drew the design.












Additionally, a student showed us how she learned to convert chopsticks into tweezers using the paper in which the chopsticks are wrapped and a rubber band. While some students worked on the boxes others worked on creating their wired chopsticks that will connect to the MaKey MaKey.




One group is ahead of the others in building their Operation game. They cut holes in their box from which players will remove the pieces. We are building the student versions of the game with removeable "motherboards." Here a student is tracing the holes cut in the box onto the motherboard. They will use the tracing for the little forms to keep the pieces from wandering away from the holes through which the player removes them.



They glued the forms to the motherboard.


We glued some ribs to the bottom of the motherboard. This elevates the motherboard so the player does not have to reach too deep into the box with the chopsticks.



The group is ready to wire up their motherboard, put foil in the forms, and construct their Scratch project!



The students behind the Homer Simpson Operation game continued working on their motherboard. They wired the board with quarter inch copper tape, making sure the tape extended inside the forms so it had good contact with the foil with which they would line the forms. 



The foil was cut into circles for the bottom of the forms and strips for the side. The students used a glue stick to apply the foil to the forms.



This group was very detail oriented and took time and care lining their forms with foil. However, I knew that we could iterate on this part of the design and perhaps come up with a quicker build for the other groups.

In the first class I suggested the students use the forms, before they are hot-glued to the motherboard, to trace onto aluminum foil the shapes for the bottom of the form area. They would then use a glue stick to glue the foil to the motherboards.


With the foil base of the form in place they could stick the copper tape to the motherboard so the MaKey MaKey could clip onto the motherboard.


Once that was done they lined the forms with strips of aluminum foil.


They hot-glued the forms to the motherboard. It was easier to work with the foil before gluing the forms to the motherboard and greatly expedited this part of the build.

In the other class I suggested that the students should put down their copper tape leads first.



Afterwards they followed the same course as the other class, putting the foil bottoms onto the board, lining their forms, and gluing the forms to the board.



Students made the bones and organs (and in Homer Simpson's case, a donut) from Sugru. It is easy to work with but I find it dries out in the packaging way too easily.


Meanwhile, a couple groups got their Scratch projects together. Their projects should have a visual feedback and an audio feedback if the player touches the foil with the chopsticks.



In the process the students learned how to import images into the Scratch Costume area and import .wav or .mp3 files into the Scratch Sounds area. Some students are making the character change colors when MaKey MaKey detects the circuit being closed, while another group makes the character gradually shrink each time the player touches the foil.

One group tested their motherboard with the software. I pointed out prior to their testing that none of us had actually tested to see if the copper tape and aluminum foil motherboards would work. My model was different then theirs. It was a relief to see that it worked!


Each game is different with the same underlying motherboard design. The Scratch projects work the same way, too, utilizing the MaKey MaKey to read a "key press," but each project reflects the young makers' personalized design.