Scratch Building Part II - Selecting a Subject
You are now ready to select your subject.  Some of the
questions you may ask yourself are:
- What size will the finished plane be?
- What materials will you use for building and finishing
- What level of scale accuracy are you attempting
- How much time do you want to spend building it.

The model we will build in this article spans 32", weighs
10.5 to 12 ounces, uses foam as its primary construction
material and is accurate in outline to the real plane. The
fusleage is not scale width.  It was built to a maximum
width of 2 inches to use the foam I had on hand.
Creating your "Plans".
The first step in scratchbuilding is creating a set of plans to work from.
Shown at left are the posterboard templates I used to build the Curtiss P40

1. Print out a three view of your chosen subject.  I usually enlarge it to fit on
an 11"X17" page (this is known as Ledger size paper).

2. Measure one wing panel on your print and divide this into 16", which is
the size of one wing panel of a 32"wing.  The result of this calculation is the
enlargement percentage.

3. Use an office copier to enlarge the drawing to size.  Most copiers today
can enlarge up to 400%.  The copier will create multiple enlarged pages that
you will tape together then glue to poster board.

4. Establish a reference line on the fuselage drawing.  I use the thrust line,
which is the center of the motor shaft as my reference line.  The wing, and
stabilizer are then made parallel to the thrust or reference line. I do not use
different angles of attack for the wing or stab.  Shown at right is a fuse blank
that has been cut out and has the reference line marked on it.

5. Now it is time to choose your airfoil.  I use the free download demo of the
Profili Program to create my wing airfoil templates.  The web site for the
download is www.profili2.com . After I print out my root template for the
airfoil I lay it on the fuselage template and mark the location for the wing.  
Sometimes, if I am concerned about balance I may move the wing cutout
ahead or back to help balance the model.  The models shown here all use
the Clark YH airfoil with no "twist" or washout.

6. User your printed airfoil template to draw the wing saddle onto the fuse
template.  Make sure that it is parallel to your thrust line.

It is now time to begin cutting out parts, click here for Part III