Granville Island wasn’t particularly close to where I grew up, so we didn’t go there too frequently. However, on the summery days where the temperature was ranking in the +20s and mom craved mussels and oysters enough to defy the law of “months that end in ‘r’”, we’d pack up the car and venture into the City.
The trip to Granville Island would always come to an end with the pervasive scent of fish when my mom would eagerly sift through pools of seafood for our dinner that evening.
Conversely, the trip always seemed to start stressful, with dad looking for parking in the sea of unmoving cars. He’d often call the oblivious j-walkers “larps,” which was a word he made up just so he could “swear” in front of mom. Of course, I suspect he said “larp” while thinking of something far less repeatable, because I’m pretty sure he wasn’t calling everyone “LARPs” in the more traditional sense of the 21st century. There weren’t a lot of castle-crashers scouring the fields of this pseudo-island back in the day.
But between the larps — again, not to be confused with LARPs — and the odeus fishicus, there was a small window of opporunity for my sister and I to explore the Kids-Only Market. Now, you have to keep in mind that, back then, there wasn’t the fancy water park or playgrounds or theatre sports or Emily Carr. There were larps, fish, and the Kids-Only Market. We had to make fun…and walk uphill both ways to get to it!
In any case, anyone who has taken a youthful stroll through the Kids-Only Market knows that, albeit ridonkulously expensive, it wasn’t your typical box store. The high ceilings – ok, yeah, those are the same as box stores — and open breezeways of this 100-year-old retired factory housed ceiling-mounted kites and mobiles fluttering in the wind, allowing the non-traditional focus on presentation for their all-natural toys.
There was one wind structure I was always fond of…always hypnotized by it’s simplistic grace…the Flying Bird Mobile.
Unfortunately, I’m not a birder and often find them boring…
…and mean…and vengeful.
But, with the exception of birds and pigs, what else have wings? Dragons!! And, relating to quite possibly one of my favourite animated movies, TOOTHLESS ONES! So I began my exercise in learning to draw… there was something about primary shapes and sketches and, I dunno, “being the pencil”… but at the end of the day, this turned out to be more of an exercise in futility. I think I could have maybe lived with the body, but the head…it just wasn’t happening.
A dragon…like…thing… FAIL!
However, for those of you who remember the theme of the S&M wedding, it occurred to me that there was one majestic facet of my psyche that I had somehow forgotten…
Unicornicopia! The Flying Unicorn!
I know what you’re thinking…or, at the very least, what my wife is thinking. You’re thinking this backstory alone is painfully long and grammatically blasphemous…and you’d be absolutely right. So I will make this long story shorter than if I hadn’t just realized it and cut straight to the technicals.
Balance is, by far, the most important “mechanic” to the flying mobile. Now, bare in mind that I haven’t done static analysis in years — but don’t doubt my pack-ratting skills…I still have my mech textbooks — so please feel free to chime in if I’m off my rocker.
In its idle state, I think you want the body to be supported by level wings. In the simplest case, assume the wings are identical rectangles. Each wing supports half the weight of the body. So you just need to find the offset fulcrum (per side) where the weight of the tip equals half the weight of the body PLUS the remaining portion of the wing.
So, say the body is 10lbs and each wing is 7lbs and 7″ long. In theory, the fulcrum should be approximately 1″ from the center such that the 6lbs of the wingtip equals half the body weight (5lbs) plus 1/7th of the remaining portion of the wing. Unfortunately, this doesn’t account for irregularities in wing form.
The Piano Theory
The piano theory came up a lot in Saskatoon whenever a garage was being built and, say, our walls were looking more like trapezoids than rectangles. That is:
It is not a piano.
At the end of the day, in the time I could have calculated the weight distribution of the irregularly shaped wings and mathematically engineered the perfect fulcrum for each of the wings, it was WAY quicker just to use trial-and-error. Case and point: it is not a piano.
I think the biggest problem with imperfect balance points is that the “flapping” motion doesn’t last very long. It’s possible that, by not having the mobile perfectly balanced such that the body idles either high or low, the inertia decays way quicker than it would if the wings idled level.
Alternatively, I’m wondering if the material weight makes a difference. I was just using thin pieces of baltic birch ply. But now I’m wondering if using heavier, denser materials would result in the mechanic having more momentum and therefore flapping longer… anyone?
I suspect it also helps to use elastic to hang the mobile. When the wings flap downward (body goes upward), the elastic would stretch. The energy stored in the elastic will then assist in pulling the wings upward, slowing down the intertial decay…I think. :)
Sadly, my Narwhalian Pegasus falls into the “imperfect balance” category with limited feathered flappery. :)