# Build a Big Piano

Many readers will remember a Tom Hanks movie from 1988 called "Big".

In the movie a young boy gets supernaturally transformed into a twenty-something man and finds out what it's like to be big.

Perhaps the most iconic scene of the movie has two of the characters dancing on a scaled up "Big Piano"- that's the scene everybody seems to remember.

They turned the movie into a Broadway musical and later licensed the show to be performed in community theatre. My local community theatre (South Valley Civic Theatre in Morgan Hill, California) decided to do "Big the Musical" as a teen show, and the production staff approached us to build a Big Piano that could hold its own next to the movie version and give our show a "wow" moment.

Not many people need to build a Big Piano, and if you do it's likely you'll have specific goals and constraints different from the ones we faced. This instructable is less of a detailed plan and more of a set of notes explaining the problems we were trying to solve and the way we chose to solve them. I hope other Big Piano builders can learn from our experience.

Remove these ads by Signing Up

## Step 1: How Big is the Big Piano?

The width of a piano is determined by human ergonomics and the pitch range of the music you need to play. In this case the piano has to be danced on and that means a white key big enough for a human foot to step on. That is: about 7" wide. The music the characters play on the piano has a 3 to 4 octave range. We went for four octaves. ie- 28 white keys, each 7" wide. We added 6" end caps to the piano So the overall length was (28 x 7) + 12 = 208".

The depth of the piano is more flexible. We wanted our piano to approximate the proportions of a real piano, and that's about a 7:1 depth to width ratio for white keys. To keep things simple we went for a overall depth  of 48".

The height is also flexible. We decided to light up the front of each key with a square of light. With some additional height details we ended up with an overall height of 12".

So all together the design target was 17 feet long, 4 feet deep and 1 foot high. That's big!
dave70222 months ago
Is that Annabelle ?
bschran1 year ago
Now you can rent it out to kids parties :-)
to be honest though that is a great idea you had there I am going to approach a local director about doing the show now, just so i can build one of these :)
Careful what you wish for.....
6 months ago

I love a good DIY challenge... by some friends I have been dubbed the Ghetto rigging king. To play on a metaphor I have found interesting ways to make a square peg fit into a round hole

Mike Alarcon8 months ago
Do you have to copy and paste al the codes into just one? :)
deadsy (author)  Mike Alarcon8 months ago

7 months ago

So, we save the .h programs and .cpp programs all of them in one place, then we use the makefile in arduino to join all of them together? how can I wire the circuit, could you show me, it's just a project for fun, I'm 16 and learning Arduino.

Thanks Bro :)

deadsy (author)  Mike Alarcon7 months ago

To build the code you type "make" (in Linux). It probably won't work for you because you probably don't have the AVR gcc compiler installed. You'll need to get that first. As for the wiring- I didn't create a full schematic because it was built off the cuff. It's a pretty simple circuit, if you know what you are doing :-) If you take a look at the source there is documentation of which specific CPU pins were used for what purpose. I'm sorry it's not more detailed but the instructable was put together more as a build notebook than as an Arduino tutorial.

DustySeven71 year ago
Up there with the one FAO toy company did for the movie, better if you ask me
In some ways it's a pity you only get to do this once. Spending some more money and time could develop a capacitive touch-key solution. That would simplify the mechanical design. I thought this one was neat:
DustySeven71 year ago
just a tip, you need a put a dummy load on the main rail of the PSU to make sure the output of all rails is clean. Check the label on the PSU either the 5+ or 12+ rail will have more amps. for the 5+ rail you need a 5ohm 10 watt resistor. For 12+ a 22ohm 10watt resistor. just take one of the many cables for that rail and a ground and put the resistor in between.
Thanks - I wasn't aware of that, but I did have a lurking suspicion that the light loading on the PS would result in the switcher running well below it's normal duty cycle. Nothing bad happened, but we weren't running the thing all day either.

This guy's gone all out:
traisjames1 year ago
What was the final cost of the piano?
Now that the show's over we are planning to sell the piano to another theater who wants to do Big- so to maintain our negotiating position we are keeping the final cost private. But - it was well within the \$2k budget mentioned.
Lindie1 year ago
Awesome! :-)
babybayrs1 year ago
Amazing and so fun!
im obsesed with piano...so freaken awsome
Muhaiminah Faiz1 year ago
wow! I wish I could make one! super duper work!