April 10, 2007

Pneumatics, Hydraulics, Solenoids, Electricity and Pigeon P**p

The special effects in Persephone make use of lots of pneumatic power, never mind all of the energy (hot air?) being expended by the hardworking cast of four. Here they are in Act I; Alfie, Demeter, 'Seppe, and Celia.

If you've seen the show you've seen a few of these effects including flowers that burst out of the hedges, dead pigeons that fall from the sky, and a fountain that magically comes to life spouting water. I've given you glimpses in previous posts. Here's a more in-depth look.

The flowers are driven by a piston, a solenoid, air, and a lot of tubing. When we want the flowers to bloom we send an electrical signal to the solenoid, which reverses the airflow in the piston and propels the flowers onstage. To make them go away we remove the electrical signal, the airflow reverses and they retract. Almost... a few of them take a little extra manual push.

The pigeons work pretty much the same way, except they are individual drops. The flowers all come out at once; the winged rats get shot one at a time so each mechanism has it's own solenoid. With the airflow going one way the bird is clamped securely in the fly loft, when the air is reversed via an electrical signal to the solenoid down comes the p**p bombing beast. Thanks to companies like Grainger this technology is easily accessible.

We originally went way high tech by installing a wireless trigger on the the fake gun with the idea that the trigger pull (by the actor) would actuate both the sound cue (gun shot) and the feathery fall. For practical, timing and safety purposes the trigger now only runs the sound cue, and the bloodily painted stuffed toy plummets on a manual call. We bought the birds online. You can find almost anything online.

The aforemention p**p that splatters repeatedly on Demeter is delivered via a jury-rigged handsoap dispenser like the kind that you find in public bathrooms. Instead of waving your hand underneath it, we deliver an electical signal, the grey colored soapy solution is delivered and gravity does the rest.

The fountain works off of hydraulic power, go figure - good old city water pressure. The water flow is triggered by sending an electrical signal to a solenoid which essentially opens a valve. This photo of the fountain is during construction. I love that there are plastic grapes underneath the finished product!

All of the aforementioned electrical signals are sent by the lighting board. The crew are too busy doing quick changes, handing off props, operating followspots and running some other of the Act II special effects to handle the above FX as well. It's simpler to have them triggered by a lighting cue.

More on the crew and the other special effects in the next few posts.

Production Photo above (Top); L to R Jeremiah Kissel, Melinda Lopez, Seth Fisher, Mimi Lieber. Photo by T. Charles Erickson

2 comments:

Robot Man said...

This is Awesome!

Cenataur said...

This is f'ing sweet!