sqrt(550/660) = sqrt(5/6) = 91%, give or take.  You could round it off to an even 90% for 535 squares.

You could just tell them the wingspan you're looking for and they will do the math.

If the sheet comes out incorrect, they will do it again without charge. Till they get it correct.

All you need to bring is a tape to measure and the plans.

Good luck.

Charles

You could just tell them the wingspan you're looking for and they will do the math.

Charles

Not the best approach if one is trying to come up with a specific wing area.  For those who understand the square root of the ratio of the two wing areas, the 91% solution by Tim Wescott above is the accurate way to go.

Just saying.

Keith

sqrt(550/660) = sqrt(5/6) = 91%, give or take.  You could round it off to an even 90% for 535 squares.

Someone just asked me how to do this in general, so here's the general formula to use if you know the old wing area and you have a new area that you want to achieve:

linear scaling ratio = sqrt(new area / old area), where "sqrt" is just short for "square root".

For another example, say you've got plans for a 500 square inch plane that you want to scale up to 700 squares.  You get

linear scaling ratio = sqrt(700/500) = sqrt(1.4) = 1.18 = 118%

So if you're doing this on a copier (a honkin' big copier) just set the enlargement ratio to 118%.  If you're generating your own build plans on paper, multiply the dimensions by 1.18.

You can work this backwards, too:

new area = (old area) * (linear scaling ratio)²

I might use this if I do the forward method and get an inconvenient number (like 118%) -- then I can pick something easier (like 120%) and do the backwards method to find out my new area.  In this case it's

new area = (500) * (1.2)² = (500) * (1.44) = 720

This may not sound too bad to me, and so I might run with it.

I've taken plans to Kinkos for enlargement.  First, I draw a scale on the plans, already reduced by the desired amount. I tell them to make the drawn scale equal 10" (or whatever you want).

That way, they only have to look at the scale for the correct plan size.  Works for reduction or enlargement.

Floyd