Times have never been better for scratch builders. Numerous plans services are publishing plans dating back to the 1930s and beyond. Many of the print wood
kits from yesteryear are now available as laser-cut kits. And
just a little surfing on the internet can produce a drawing of
virtually any aircraft imaginable.
One thing about builders is that we seem to thrive on
personalizing our projects. Maybe we need to add a little more
detail than what is found on the plans. Or perhaps we want to
convert a scale model to a different variant.
One of the most common modifications is to change the
scale of the plans. Maybe that 19-inch Earl Stahl Grumman
Wildcat got your attention, but it’s too small for the spare
motor and servos you’d like to use. Or maybe you’d like a
1/8-scale Douglas Devastator to fit in with other models, but
the best plans available are a different scale.
I often hear from builders who are uncertain how to resize
plans. It’s actually quite simple, but with that said, there are a
few guidelines that come in handy.
What Scale Is This Model?
A common question that builders ask is what scale are these
plans? This is particularly true when working with designers
who group their designs by wingspan instead of by scale.
Builders have good reasons for asking what scale their
project will be. A key reason is to make sure that detail parts
will be the right size. For example, pilot figures are usually
described by their scale. Putting a 1/8-scale pilot in a 1/12-scale
cockpit will look odd.
As an example, I’m currently working on a Curtiss Hawk 75.
The wingspan for this project will be 60 inches, but what scale
is that? The math needed to answer this question is simple.
We only need to know the wingspan of the model and
the wingspan of the actual airplane.
In the case of the Hawk, the full-scale aircraft had a
wingspan of 37 feet, 4 inches. As mentioned, the model
has a 60-inch wingspan. The first step is to get both of the
wingspans into the same units—in this case either in feet
or in inches.
25 Model Aviation JULY 2017 www.ModelAviation.com sponsored by HOW-TO issue