Monday, May 25, 2015

Programming Organic Shapes in Beetle Blocks for 3D Printing

Eric Rosenbaum's Beetle Blocks is a programming environment built on, I believe, SNAP. It uses a familiar block programming metaphor to produce STL files for 3D printing in an unconventional manner for those of us used to using CAD programs to design 3D models.

The included examples include a few different shell shapes that demonstrate how to make the beetle extrude and move in interesting patterns. I decided to head to the beach with my son to collect some shells. I would try to program their general shapes and see what kinds of models I could create for 3D printing.

While my son collected quartz I went looking for shells from the common slipper shell, a sea snail. There is a beach further down the coast where there are hip-tall piles of these shells.

When they are alive, the sea snails cluster in clumps around a stone or a buoyant object: I once found many clinging to an old golf ball!

I brought home a sample of the shells. I started by examining one of the Beetle Blocks projects that generates a shell. I figured out what the combination of blocks did, then remixed the project to approximate the shape of the slipper shell. One simply exports an STL directly from Beetle Blocks.

I tried and failed to get MeshMixer on Ubuntu 14.04 to slice a plane from the bottom of the model to flatten the base: Meshmixer will not save. I used Tinkercad instead.

I sliced the model in ReplicatorG and specified 0% infill. Still, the model had some strange complexities to it because I was rotating on the x and y planes (I lost that work and had to recreate it for the screenshot above but could not remember how I did the x rotation in the model I originally generated).

I printed the model on my Thing-O-Matic. Originally I scaled the model too small and the filament retraction eventually worked the filament loose in the extruder.

Scaling the model up resulted in a strange, complex, but very organic looking 3D print.

As I continue to program in Beetle Blocks I am beginning to understand how to control the extrusion and movement on the x y z axis creates interesting designs. I already have a couple of designs in mind for fantastic snail shells that curve around an axis.

I look forward to the opportunity to talk with Eric about Beetle Blocks and to better understand this unique programming environment.

Thursday, April 30, 2015

Constructing Cardboard Automata

I wrote an instructional article for Make Magazine's online edition. Head over and learn to build your own simple automata.

Monday, April 20, 2015

Marble Machine

The Marble Machine is one of the best MakerEd projects you could hope to unleash upon a group of students or adults. It does not plug into the wall or need recharging, does not connect to wifi or the Internet, and can be used by young and old alike. It takes less than one minute of direct instruction on the nature of the challenge and a showcase of the parts. After that, a primal instinct takes over to get the marble to the bottom of the board, no matter the amount of frustration that ensues, and hard fun is had by all.

My friend Joseph helped me build my Marble Machine using plans from The Exploratorium. The pegboard surface is rugged but lightweight, solidly constructed.

After Joseph and I finished constructing it, I took it home and turned my three year old loose on it.


In addition to some of the parts The Exploratorium suggests, I upcycled an egg carton into a spinning cup contraption.

Next, I brought it to school. The students quickly devised a way to get the marble from the top to the bottom, but it traveled very fast. The Maker Club played with it on several occasions, and it was sometimes available during rainy indoor recess.

The faculty liked playing with it once, too. Notice that they are timing themselves on the iPhone.



The faculty also tinkered a new use for the clothes pins that drastically slowed the marble's descent down the chutes.

The faculty set a record of a little over 6 seconds for the marble to travel top to bottom.


Next, I unleashed the Marble Machine at the Westport Library's Teen Maker Monday workshop. All but one of the five students arrived late, so I only had to teach one person how to use it. Four of the five students were completely engaged for an hour and twenty minutes, refining the design, tinkering, engineering, and persisting without any assistance from me.

Clothes pins helped keep the marble from overshooting the elbow joint.

The level of cooperation of collaboration was impressive.

Here is their first record-breaking run, at 7.54 seconds!

Afterwards, the students were challenged to break the 10 second mark.

The final good hack for the evening was using some of the split foam tube as a marble chute.

Their final run took nearly 9 seconds!

Build a Marble Machine today! It is a great hand-on activity that absorbs everyone in the room. People are naturally drawn to the challenge because there is no learning curve. People stay with the challenge because though it seems simple, it is devilishly difficult! Perfect hard fun.

Tuesday, April 14, 2015

3D Printed Silhouettes

I remember sitting at Disneyland between rides, a compromise to sit still long enough to have a paper silhouette cut. My grandparents had them of my mom and uncles, and my mom was determined to continue this crafty, beautiful tradition.

While brainstorming ideas for a 3D design and 3D printing five day workshop for elementary and middle school students I facilitated, I came up with the idea of creating 3D printed silhouettes like the ones I sat for at Disneyland. However, instead of paper the students would use laptops, software, and a 3D printer to create their silhouettes.

The classroom was near a white stairwell door with bright, natural light streaming in during the afternoon when the class met. We set up a stool for the students to sit in front of the door in profile. The laptop was set on a cart. We captured the images in Photo Booth, imported them to iPhoto to adjust the contrast, then converted the files to .svg in Inkscape.

The test model was printed on my MakerBot Thing-O-Matic. I added a small frame and a little hoop to hang the silhouette in a window.

The students' sihouettes were printed on a MakerBot Replicator 2. The first model was printed larger than subsequent models because of time considerations.

The silhouettes worked best if the girls pinned back their hair, or at least had it back over their shoulders: otherwise, the silhouette might have too little detail.

This is a great starter 3D printing project to encourage you to use your powerful new tool to create, rather than just printing things from Thingiverse. With a few simple steps (I outline the details of the Inkscape process here) you have a unique keepsake that would make a great Mother's Day present.