Part 1 of this article covers the basic parts list, code, and assembly.

Now that the Enchanted Rose Prop is nearing completion, I wanted to cover a few final details. Here’s a video of the app and prop in its current form:

Aesthetic Touchup

Some paint and floral tape was used to give the stem a little more rose-like appearance. Still in progress, but you get the idea.

Ring Lights

The ring lights are a Neopixel 1 meter long strip. I cut the strip between the LEDs at roughly the 40 LED mark. Doing so has no effect on the Neopixel, as long as you cut between LEDs.

Big gotcha: These lights only want 5V maximum! I fried the first set by overpowering it. Don’t make that mistake — it’s irreversible.

Stem Accent Lights

I purchased a cheap set of LED lights to add some interest to the stem.

These are powered by their own 3-AA battery pack. I’m sure I could use the same 3 AA-battery pack used by the Neopixel strip, but after frying one of those strips, I chose not to risk wasting another $30 tempting fate. To turn these on and off, an N-channel MOSFET transistor is used, with its gate actuator tied to pin 10 of the Arduino.

Basically, the MOSFET transistor lets current pass through if voltage is applied to the Gate pin (pin 1 in the diagram above.) When voltage on the gate goes LOW, the LED accent lights turn off. When voltage on the gate goes HIGH, the accent lights turn on.

Soundproofing

The servo motors are a little squeaky when moving. I installed some foam sound barriers (ordinary shipping packaging) to help dampen the sound.

Drop Mechanism

The initial approach of using piano wire to move flexible wires up and down worked fine from a dropping standpoint, but it had two distinct disadvantages in practice:

  1. the vertical extension above the bud made it hard to get the upper petals to to look real
  2. the “re-set” procedure was going to be way too hard for young adults to do Did I mention that after I had the prop working for an adult, my wife told me that the crew would be entirely comprised of fifth graders? “Hardening” the prop for fifth grade use for 8 performances in ways such as this was actually the most time-consuming part of the project.

So instead, I revised the attach/drop mechanism. I drilled four holes into a wooden 1 1/2″ golf-ball, and used rod magnets which are inserted into thread covers and put into a spring:

[Result: TOTAL SUCCESS. Worked flawlessly in production and could even be re-set by kids (though I admit I double-checked pre-show.)]

The fishing line is pushed through the (orange) nylon thread cover and a double knot is used to prevent it from pulling through. Then, the rod magnet is inserted, finally that’s inserted into a spring. That subassembly is repeated three more times, and inserted into the four holes in the wooden “bud.” You’ll want to make the exit hole for the fishing line quite a bit smaller than the upper hole, so the springs have something to push against. The only thing that comes through the bottom of that wooden ball is four strands of fishing line, which are fed down into the stem, one to each of the four servos.

The petals have a small metal washer hot-glued to the base, which is magnetically attached to the bud. When the servo motor turns, the rod magnet is pulled down about a half inch to an inch into the chamber, and this action causes the petal to fall. The servo motor returns to “slack” position and the spring returns the rod magnet back to its ready position.

The petals can then be reattached.

This drop mechanism is much more durable, and now that the magnets are “self-resetting”, I’m thinking of switching the slider-control based drop mechanism to a simple push-button interface. (Update: I did so, and those changes are reflected in the Github code. It’s a simple four-button interface for the drop mechanism, one for each petal; this initiates a retraction of the servo, a pause for a second or so, and then restoration to the ready position.)

Epilogue

The performances— all eight showings — were smashing successes!

Izzy, the fifth-grade prop controller, did a great job controlling it and the prop functioned just as designed.

If there was a flaw, it was that one of the petal drops (of the 32) worked but got hung up on the LED light bush below it, so it appeared not to drop, but that was pretty minor and not a big deal.

Note that I did decide to replace the full set of AA batteries in the entire prop after the fourth performance. I can’t speak to whether that was unnecessarily premature, but there were no battery failures. Each performance was about 90 minutes, and the power to the prop was turned on about a half hour before and after each performance.

The Enchanted Rose Prop is now in the hands of the school theater director (and computer tech teacher; she’s one and the same) as a partial thank-you for all her great work with the kids.

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Author

Steve's career has included leadership and entrepreneurship in consumer apps, online travel, games, relational databases, consulting and telecommunications. Steve founded BigOven, the first recipe app for iPhone, now with more than 13 million downloads, which was purchased in 2018. Steve served as Chairman of Escapia Inc., the leading SaaS solution for the US vacation rental industry, now part of Expedia. Steve was co-founder, President, CEO and Chairman of VacationSpot, a pioneer in the online reservation of vacation rentals, bought by Expedia in January 2000. At Expedia, Steve was Vice President of Vacation Packages, leading the vacation package and destination services teams, helping to create two patents on the first-ever dynamic vacation packaging system on the Internet, which now represents billions in annual transactions for Expedia. Steve has keynoted on several occasions at the Vacation Rental Managers Association (VRMA) and taught a course on the management of innovation at the University of Washington Graduate Business School in Seattle, Washington. Steve worked for Microsoft from 1991 to 1997 in a variety of senior marketing and executive positions, and led the creation of the internet games group, helping develop several products and patents related to online multiplayer gaming. He helped launch Microsoft Access and was involved in the acquisition of Fox Software by Microsoft in 1993. He's worked for IBM, Booz-Allen Hamilton and Bell Communications Research. Steve holds an MS in Computer Science from Stanford University in Symbolic and Heuristic Computation (AI), an MBA from Harvard Business School, where he was named a George F. Baker Scholar (awarded to top 5% of graduating class), and a dual BS in Applied Mathematics / Computer Science and Industrial Management from Carnegie Mellon University (CMU) with University Honors. Steve volunteers when time allows with Habitat for Humanity, University District Food Bank, YMCA Seattle, Technology Access Foundation (TAF) and SPEAK OUT Seattle, among other groups.

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