Design and Build
Model Aircraft for Light Weight and Strength
I have finally heard one conversation too many discussing the weight of
glues in the context of having any significant effect on overall weight
of a flying model airplane.
I could build an entire model using nothing but epoxy,
which is probably the heaviest glue there is, and still have a lightweight
airframe. The weight of glue in an R/C model is
inconsequential when properly used even if the wrong glue is used.
So why not use epoxy throughout? Because it simply isn't the best glue to
use in most cases.
- Epoxy is often harder than the materials it is bonding
which makes sanding a smooth seam difficult.
- Epoxy is expensive.
- Epoxy is less convenient than single part adhesives.
- Epoxy takes longer to grab than water or solvent based glues.
But this is not an article about what kind of glue to use in your models. It's
about how I've learned to consistently design and build models that are
significantly lighter than comparable models from other sources and how you can do the same.
Generally speaking, if my model isn't lighter, then it has more features for the
same finished weight.
By the way, these are the building techniques I use and advocate.
They are not my original ideas and concepts. Almost every technique I discuss in this article has been
around for a very long time.
These building methods have stood the test of time from when they were developed back in the days
when radios weighed as much as a car battery and engines had half the power
they have now. Builders had no choice but to use building methods that
kept the weight low and the strength high.
New designs, especially those put out by major manufacturers, take
advantage of the fact that radios are lighter, engines are more powerful
and the customer base is primarily the instant-gratification,
it's-not-worth-it-if-there's-actually-work-involved crowd. Many of the most
popular kits today are poorly engineered to the extreme. More about
this to come.
The problem that I am seeing is that most designers base their engineering
methods on kits
that they've built. In this case it means they are emulating poor
designs not knowing that anything is wrong with them.
Consequently, model aircraft structural design is doing a Darwin in
Please note that my philosophy doesn't necessarily build a model that
will withstand your piloting or your flying field.
If you know your planes will take a lot of abuse you will have to make
them beefier to withstand it unless you like doing lots of repairs.
In this series