Many projects require moving parts.  It might be a cause-and-effect display with jumping seahorses, a chain-driven clock, or simply a sign with spinning letters.  In each case, a unique (in the literal sense of that word) mechanism must be designed, machined, and assembled.

Pacific Gunner

Project: Pacific Gunner: another zero-dollar project. We had an old computer with an old video game program that had until recently occupied an old cabinet. Someone decided it would be a good idea to get it back on the floor and so asked me to refurbish the cabinet and spruce up the game. Well, the cabinet was past the point of refurbishment and the game would brook little sprucing. Fortunately, someone had (long before I arrived) purchased large stick-on graphics for the sides.

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Match the Moon!


I designed this interactive for the Planetarium Queue at the Maryland Science Center.  It’s super-simple: there are two large wheels on the front.  The left wheel has images of six planets; the right wheel has images of six moons.  The visitor rotates the left wheel to select a planet and then the right wheel to select the corresponding moon.  When a selection has been made on each wheel, the “Check Answer” button on the control panel illuminates.  Upon pressing the button, the visitor will discover if he is “Correct!” or if he should “Try Again!”.  Even thought this interactive is simple, it garnered high dwell times during prototyping.

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Place the Planet!

I designed this “Place the Planet” interactive for the Planetarium Queue at the Maryland Science Center. The basic idea: to have the visitor line up the planets by increasing distance from the Sun. The positive reaction during prototyping led us to add a similar activity wherein the visitor arranges the planets in order of increasing mass, which we considered (and found to be) slightly more challenging.

Ejection Mechanism

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Project: In Cahners Computer Place, there is 1/3 (cut lengthwise) of an automobile against the wall, around which is a Plexiglas barrier, behind which is a mural of a civic emergency.   Hidden in this car is a faux improvised explosive device (IED).  Within this small corral is a MARCbot.  The MARCbot is a small, wheeled robot with a camera at the end of an articulated boom designed and built specifically to inspect potential IEDs.  It is operated with a remote control unit called an Operator Control Unit (OCU).  This is where I came in.  Even though OCU was designed for combat situations, it was nowhere near robust enough to withstand the museum-going public.  (The preceding sentence is in no way a joke.)  I was asked to design and construct a kiosk that would house the OCU, make it more accessible for people with varying manual dexterity, and to add one final feature, to be explained below. For a sneak preview, see the video below.

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Cause and Effect: New and Improved!

This entry concerns an extensive refurb on an exhibit I designed and built years ago. The original exhibit can be seen here.

For this refurb, the manager of the Children’s Discovery Center obtained grant money to 1) update the display’s mechanics, 2) utilize the area behind the display to incorporate a 3D underwater scene, 3) to build a splash wall to separate the Cause and Effect area from the water-table area behind it. Further, an infant’s mobile and a graphics display explaining experiments that parents can perform using the mobile were added to the area. A discussion of each sub-project can be found at the links below.

Improved mechanics

Underwater scene

Splash wall

Infant’s mobile

Yellow Submarine

Time Flies!

This is by far the largest single project I have completed for the museum. Graphics aside, nearly every physical aspect of this exhibit was designed and constructed by me. This entry will cover the overall design, cabinetry, control circuitry, mechanical devices, and even the mode of interaction. Due to this entry’s complexity, I will cover Time Flies! in several sub-sections, each accessible by one of the links below.



PER3 Interactive

Fly Cam

Sneak peek for the Fly Cam!

Robot Park Sign

Project: Make a kinetic sign for the Robot Park exhibit.  You can see the Robot Park exhibit here.

Challenges: This project was less challenging that it was simply fun – it’s one of my favorite gadgets I’ve made for the museum.  We wanted to make the Robot Park exhibit at least marginally goal oriented.  To reward the visitor for accomplishing a specific task, we decided to have the sign for the entrance to the virtual Robot Park flash, whirl, and oscillate once the goal was achieved.  Actually, there was one challenge that readers of this website will recognize as a recurring theme: no money.

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Project: A kiosk where visitors can take pictures of their ears, measure them with a computer program, and compare them to the ears of others on a computer-generated graph.  It must be more fun than it sounds because this kiosk gets about 200 hits per day.  (We know because the ear-measuring program stores all the data the visitors enter. ) As an interesting aside, we tried this exhibit first with noses, and very few visitors would participate. Apparently, people do not like to take pictures of their noses, but have no problem storing images of their ears in a database.  Go figure.

Concept drawing for EarCam arm.

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Project: Poor vision is frequently caused by the condition wherein one’s retina is no longer located in the lens’s focal plane. This displacement can be either in front of the focal plane (hyperopia), or behind it (myopia). For this project, I wanted to show how the location of the retina could affect the focus of an image and how corrective lenses are used to compensate for these conditions.

Check out this riveting – riveting! – video of the Sliding Retina.

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