The Crankamacallit iPad app started with a story and a cardboard box. I wrote the story for my son, and together the two of us built the ever-changing Crankamacallit, an imaginary vehicle.

Today I will build you a Crankamacallit   
 
With pieces and parts from my carpenter's kit.
 
With buttons and levers and yes, of course—CRANKS! 
 
With switches and gears and an old baseball mitt. 

 
I know you have dreamed of a Crankamacallit, 
 
Downtown I applied for a building permit. 
 
Constructed with pulleys and nails and some glue,
 
Look, here are the blueprints that I will submit. 

 
We cannot assemble just any old thing, 
 
That’s held tight together with wax and some string.
 
These days, one must have quite a “serious plan”.
 
Mechanical drawings, that’s how I began. 

 
The cranks will turn round on our Crankamacallit
 
Up, down, and around! Yes it’s lickety split!
 
The speed of a racecar, the sound of a train! 
 
Clang-bang! Hammer, hammer! It won't ever quit! 

 
What fuel will we use for our Crankamacallit?
 
To make it light up and to make it transmit? 

(To broadcast your favorite cartoons and movies!

Run green glowing headlights and still babysit!)

	
Will oil be the thing to make its motor sing?

Or maybe hot steam from a deep thermal spring . . . 
 
A hybrid of solar and power from the wind!  

A man made machine that is feathered and finned! 

 
We’ll add some big wings to our Crankamacallit,
  
Or blades from a windmill that we’ve retrofit.
 
We’ll blow up balloons till it floats in the sky! 
 
Or Grandma may hoist it on cables she's knit! 

 
But will it keep going? You ask, with a frown.
 
It's working well now, but what if it breaks down? 
 
Does it have a battery I can replace?   
 
These parts look like they came from dark outer space! 

 
Oh no! Hear the motor? It’s broken—it’s stopped! 
 
We’ve only just finished! It SNAPPED! Something POPPED!
 
It gave a small sputter . . . a quiet dry cough . . . 
 
Then water ran out of the tin gutter trough! 

 
Quick, press that red dot on the Crankamacallit!
 
Unlatch the hatch, climb inside—can we fit? 
 
You first! No, you first! Watch your step—watch your head! 
 
My goodness! This looks like an orchestra pit! 

 
Brass trumpets and tubas—a violin bow! 
 
And also a change in the weather—that’s snow!
 
A basement that's full of old junk! And a motor!
 
What in the world? An enclosed ANIMATOR! 

 
No wonder! A leak! In this paramount part!
 
Let's listen: Drip drop! Hear it stop? Hear it start?
 
A fountain! It’s inside! It beats like a heart!
 
Why, we must repair it! We’ll fix it! We're smart!
 
We'll follow instructions on this special chart. 

 
This valve; make it tight, now please shine your flashlight . . .  
 
And drill! Turn the crank! Tape, tacks, pliers, a kite . . .
 
Let's climb out and look—check the monitor screen,
 
Coast clear! Now right here, press the button that's green . . . 

 
It hums! Hear it whir! It’s the Crankamacallit!
 
All gizmos and gadgets, a number one hit!
 
This toy will make breakfast, blow bubbles, and sing!
 
Together we built it, ourselves! Bit by bit.