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• Artwork FTW

  scubabear • 11/14/2016 at 20:26 • 0 comments

  Rachael wasn't satisfied to use any of the photographs that she found of Harry Houdini for this altar, so she took the time to paint her own portrait of him:

  It was the perfect touch to keep the handmade-feel of the altar.

  Another traditional aspect of La Dia de los Muertos is papel picado, artwork made of cut paper that is very popular at the Day of the Dead. Magic Castle and Boo Crew member John Eddings made some really wonderful papel picado files for us that I was able to cut a large quantity out of construction paper using my Boss 1416 Laser. These also turned out really great, and I've included the Adobe Illustrator artwork file in the files section for anyone who is interested in taking a look.

  
  

• And the rest...

  scubabear • 11/09/2016 at 04:57 • 0 comments

  ...was much easier. The crystal ball was a Halloween prop that Rachael found in town somewhere, and it is similar to this one on eBay:

  http://www.ebay.com/itm/Witches-Crystal-Ball-Magic-Light-Orb-Fire-Ice-Red-Lights-Halloween-Decoration-/401206398890
  

  But in person, the plastic ball looked really cheesy, so the main modification we made here was to tear it apart and put the lumia mechanism into an actual opal glass ball, like teh ones used on lamps. This really improved the look of the thing. Other changes we made to the mechanism were reductive, such as cutting the wires to its speaker and rigging it to be triggered from a relay closure. This was easy because the crystal ball prop has a demo switch mode that, when the switch is pressed, it runs the demo for about 45 seconds and switches off on its own. This was perfect for our application, so the only other mod we made was to run it off 5V instead of the batteries it was designed for. Another wall wart transformer & we were good to go.

  
  

• Making the Chains Fall...

  scubabear • 11/09/2016 at 04:34 • 0 comments

  The Houdini portrait has two separate chains crossing it; the concept was that they would fall down when an RFID was scanned. (In this implementation, the RFID was used to trigger the altar gag; a random number generator in the Pi determined whether the member would see the chains fall, or hear the audio clips, or get the crystal ball light show.) These falling chains were the trickiest part, not because it's hard to make chains fall, but rather because it's tricky to figure out how to get them to reset afterwards.

  We thought about this for a while with various mechanical contraptions being discussed, but we were running out of time. It was about four days until we had to install the altar, and we were still trying to decide how to build this mechanism. Suddenly I remembered a trick I'd seen my friend Milt Larsen use for another gag in the Castle years ago, and it seemed perfect for the quick-and-dirty needs of this. I suggested we use a pair of replacement car power antennas as makeshift linear actuators. They seemed well-fitted to this-- 30" of throw, reasonably fast, and all the control electronics built in.

  The antenna has a pair of power wires (+12 & GND), and a blue wire that determines if the antenna goes up or down. Connect it to +12V and the antenna rises; open that connection and it retracts; this was easy to do with the relays I connected to the Pi board. If +12V is fed through a relay also, I could control if the antenna rises or retracts all the way. (In practice however, we used the full 30" throw).

  In practice, although I had four relays, I really only used the up/down function on the blue control wire. The two antennas were connected in parallel for both power 7 ground, and the blue wire was switched to +12V and open, depending on if I wanted the antennas to go up or down.

  The chains were simply attached to the top of the antennas with a bit of string:

  And the Pi did the rest!

  
  

• Making the themed RFID readers...

  scubabear • 11/09/2016 at 03:34 • 0 comments

  ...was actually really easy. I'd build RFID reader plaques for the Castle for previous Halloweens that were owl-themed, but this year we wanted to do something different. In a collaborative session Shiloh suggested using these cheap plastic skulls I bought a bunch of from Dollar Tree for a gag I didn't end up making, and making those into the RFID readers. What a great idea! It was really fun making readers from these skulls. I just cut the plastic skulls from Dollar Tree in half, put in 10mm RGB LEDs into the eyes, and wired them to where the red/green LED on the RFID reader was attached.

  The RFID reader kits from Amazon, $15.
  

  
  

  The RFID reader board was removed from the housing, the red/greed LED was desoldered, and the blue and red pins of the 10mm RGB LED "eyes" were wired in place. From there the receiving antenna loop was hot glued into the top of the skull, and the circuit board was glued on top of the back of the RGB LEDs. Then the whole thing was attached to a piece of cut acrylic that was covered with themed fabric, and voila! The Dis de los Muertos-themed RFID readers were ready for Halloween week at The Castle.

  
  

• Why Pi...?

  scubabear • 11/09/2016 at 01:26 • 0 comments

  I should take a moment here and explain why we're using Raspberry Pis. As a platform for playing back high-def video, passable audio, embedded control and internet connectivity in a $35 platform makes it pretty damn cool. We also had these RFID key fobs that the members could obtain to "activate" special effects around the Castle during Halloween week. In previous years we made the key fobs in the shape of an owl (mascot for The Magic Castle), but this year they decided to change the shape to something festive & fitting for La Dia de los Muertos:

  These are the RFID-based Magic Keys (That's Magic Castle founder Milt Larsen with the crystal ball to the right)

  Inside the little laser-cut and -etched acrylic skulls is a 125kHz RFID tag that is associated with the member's name and member number. By using cheap USB-based RFID readers that plug into the Pi, it is easy for us to see who has visited which gag inside the Castle, tailor their experience by addressing them by name or something as an option in the future, and even just get a "heart beat" from the gags and know that they are up & running. By using Pis we are able to have gags keep track of day and time, so we can have gags adjust what they do depending on if it is Wednesday (Member's night), Friday night (a crazy time!), or Saturday/Sunday brunch, when kids are in the club. And because the Pis sit on the network, they keep their time set accurately and can log to a central site Shiloh created for monitoring to see which gags are popular and which ones could use some attention. This project focuses only on what we did for Houdini, but there are many other gags at the Castle using Pis with and without RFID.

• Rachael does research...

  scubabear • 11/09/2016 at 01:08 • 0 comments

  Rachael got busy really quickly. She did web searches and located hundreds of Houdini images and read lots of Houdini lore, and was particularly intrigued by Houdini's side-line career of debunking seances while still wanting to believe that somewhere, some way there was an afterlife that could be reached. This fascination of Houdini's led to his pact with his wife Beatrice that should he die first he would try his best to reach her from "the other side". They established a code phrase between the two of them so that the authenticity of the contact, if it should occur, could be verified. There was a song that Bess Houdini would sing on stage; the song was "Rosabelle", and the Houdini's considered it "their song". The words Houdini was supposed to use were he able to connect from the other side were "Rosabelle Believes"; thus this song became the music that Rachael wanted the altar to play. The seance-debunking and medium-busting habits of Houdini led to Rachael's inspiration to include the crystal ball on the altar as well.

  
  

  Houdini was most famous as an escape artist, so the falling chains would be a must-have, of course. Rachael was able to find some lightweight plastic prop chains that looked great from somewhere, and she wanted those to fall on one of the RFID triggers, and reset afterwards.

  The chains were to be wrapped around a portrait of Houdini, and taking a photograph of Houdini and blowing it up just didn't have the look Rachael wanted, so she got busy and painted a portrait of Houdini herself to use for the altar.

• Here we go...

  scubabear • 11/09/2016 at 00:23 • 0 comments

  The first thing we had to figure out was what the altar would do. Rachael researched both what common elements of Dia de los Muertos altars usually are, and the life and legend of Harry Houdini. She decided that she wanted a portrait of Houdini with chains across it that would fall (and reset on their own), a crystal ball with some sort of lighting effect, some audio effects, and a mess of flickering LED candles.

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