09Arado.lt1.doc
[headline: Arado Ar.396]
[subhead: CL model employees cardboard construction techniques]
[Author: Chuck Felton]
[Photos by the author]
[sidebars (specifications and construction tips) in text file]
[Other callout thingy: Read the entire article in the digital edition of visit www.ModelAviation.com and search for Arado.]
SPECIFICATIONS
Type: CL Scale
Wingspan: 60 inches
Length: 49 inches
Wing area: 541 square inches
Weight: 74 ounces
Wing loading: 19.7 ounces per square foot
Power system: .40 to .50 sized glow motor or equivalent
Construction: Primarily cardboard
Construction Tips
Before you begin building, take a look at these special tips for working with cardboard.
Adhesive: Water-based glue, such as white glue or Titebond, is recommended. Contact cement is not recommended, because parts cannot be shifted when gluing surfaces.
Folding: Scoring the fold lines is done with a screening tool available at any hardware store. It consists of a handle with a 11/2-inch radius wheel at one end, which is run along a metal straightedge on the fold line.
Finishing: Cardboard gives a solid surface with no open areas to cover and is nonporous. The easiest finishing method is to give it two coats of clear dope, sanding lightly between coats using 400 grit sandpaper, followed by two coats of color dope.
A wide variety of finishing materials can be used on the cardboard including coverings such as Solarfilm, MonoKote, and vinyl paper. With any of these, it is recommended that the surface not be doped, to result in a better bond.
Paper tape: All seams, joints, and exposed edges of the model are covered with strips of gummed paper tape. Obtain a 1-inch-wide roll from a stationary store. Simply cut a thin strip to length, dip it in water, and smooth it over the seam.
Construction: Being sure to note the direction of the corrugations when cutting out the cardboard parts. Score and fold cardboard parts as indicated on the plans.
The Arado Ar.96 was a low-wing, single-engine aircraft of metal construction, which became the Luftwaffe’s standard advanced trainer during World War II. However, as the war progressed, it was decided to redesign the Ar.96, the chief goal being to save metal. The result was the Arado Ar.396 which was constructed primarily from wood.
These aircraft were to be built in factories in occupied France, but the subsequent course of the war made that impossible, and production was moved to Czechoslovakia. Only a few aircraft were built by war’s end and none were pressed into service. After the war, roughly 200 aircraft were built in France by SIPA and were used for training and as counterinsurgency aircraft in North Africa. The latter aircraft were fitted with wing racks for carrying light bombs and rockets.
The Arado Ar.396 model presented here is simple in construction and inexpensive. It uses 1/8-inch corrugated cardboard as the primary building material, which greatly reduces building time and cost.
The design makes use of cardboard’s unique features in that it can be used in large sections and folded. Each wing panel is built from a single piece of cardboard scored and folded at the LE with cardboard ribs and a single spar.
The tail surfaces and fuselage are primarily cardboard with little internal bracing required. The result is a low-cost, fast-building model that has good, scalelike appearance and can take plenty of punishment at the flying field.
Cardboard varies in weight, but any 1/8-inch corrugated cardboard will do. Sources of this material include box manufactures and local shopping centers where you can find stacks of discarded boxes.
Look for cardboard with brown paper on one side and a white-finished Kraft paper on the other side. The white paper on the outside of the model results in a smoother finish and a neater appearance. The method of folding the cardboard and using gummed paper tape to seal the joints and exposed corrugation is explained in the construction hints.
The model has a 60-inch wingspan and a length of 49 inches. The bottom of the airfoil is flat with a curved upper surface, created by the scoring and folding technique employed.
A .40 to .50 size engine can be used. My model is powered by a .40 engine and has a fully fueled flying weight of 74 ounces. This weight, combined with the 541 square inch wing area, results in a wing loading of 19.7 ounces per square foot.
The accompanying pictures should generally describe this build. The entire article can be seen online at www.ModelAviation.com/Arado or in the digital edition.
—Chuck Felton
charlesfelton@earthlink.net
Sources:
AMA Plans Service
(800) 435-9262, ext. 507
www.modelaircraft.org/plans.aspx
Chuck Felton’s website
www.feltondesignanddata.com
