Pneumatics, Laser Cut Monsters, and Living Hinges

The Innovation Center recently came by several 100 count boxes of 1 mL and 3 mL syringes, and we set about seeing how we might work them into an activity for an upcoming STEAM camp, inspired by this post from @zackboston…

Fierce Hydraulic Jaws being prototyped @Learn2TeachSETC for our 7-10 year olds at our free summer STEAM camps! pic.twitter.com/1t6MMdaC03

— zackboston (@zackboston) July 1, 2017

…which led to this video from Ivydale Science & Technology Service…

To start, we duplicated the procedure detailed in the Ivydale video above to create the basic model…

…and then set to work seeing how we might use the laser cutter to create the monster form, with the goal of streamlining the production process to minimize taping and hot gluing. I created several iterations in Illustrator, and the laser made quick work of the card stock.  Here’s a closeup of the “final” version, which securely holds the syringe without tape, and which requires only a small bit of hot glue to attach the plunger to the hinge mechanism…

Here’s a pdf of the file used to create the monster. It’s sized to cut two ovals from an 8.5 by 11 sheet of card stock. To make the file work on our laser, the strokes have to be set to “hairline” in CorelDRAW, or .001 weight in Illustrator, pure RGB red (255.0.0).  Overall, I’m happy with how it’s working, though the small syringes – a 1 mL on the monster and a 3 mL for the remote – make for a sort of dreamy, organic, delayed reaction that only operates on the push…

The basics established, I set to work creating a mix-and-match, interchangeable eyes-and-teeth system, cut from 1/8″ hobby plywood.  I’ll upload the vector files of all of these once I get them finished up.  With the laser cutter humming, one idea led to another (as they often do), and I started to wonder how a living hinge might be incorporated into the design. The results are interesting, and there’s probably a whole other related project in there somewhere…

Fascinated by living hinges, Nathaniel (student) and I began experimenting, and were able to take an 8 inch paper hinge…

…and stretch it to 80 inches before it started failing!

Next, I dunked a yet-to-be-expanded laser cut paper living hinge in a mixture of glue and water, and then stretched it out and let it dry…

As predicted, the glue and water mixture stiffened the paper, and it kept its shape (mostly) once dry.  There’s a lot to be explored with living hinges – jumping off points include Patrick Fenner’s Laser-cut Lattice Living Hinges, a fascinating look at the math behind them, and this Customizable Tessellating Living Hinge by drxenocide.  There’s nothing quite like having the tools, materials, and time to work an idea!