In 1914, Claudius Dornier established a company called Dornier Flugzeugwerke. Throughout its long history, the company produced many innovative designs for both the civil and military markets.
After World War I, the Treaty of Versailles prohibited Germany from producing any airplanes that could be converted for military use. To bypass this prohibition, Dornier moved the production to Italy, Japan, Spain, the Soviet Union, and the Netherlands. In 1931, Dornier returned production to Germany.
Until the beginning of World War II, the Dornier company concentrated on producing seaplanes. Its most successful design was a two-engine Do J Wal and more than 250 of them were produced. European and South American airline companies used a large number of Wals.
In addition to the two-engine Wals, Dornier also built 19 four-engine R4 Super-Wals that could carry as many as 19 passengers.
I have always enjoyed seaplanes. My preferences are multiengine scale models. I had my eyes set on the Dornier Do R 4 Super-Wal for a long time and I finally drew the plans and built the model.
It was built from balsa and plywood. For power I used a brushed Speed 400 with a 2:1 gear box. After several years of flying my Super-Wal, I damaged the model beyond repair and so I decided to build a new one.
The new model would be built mostly from foam boards that I purchased at the dollar store. The model is powered by two 2820/14 motors in the front of the nacelles and by two 2212/34 motors in the rear of the nacelles.
The front 2820 motors are powered by a 3S 5,000 mAh battery turning the 9 x 6 propellers at 23 amps each. The rear motors have a 3S 3,000 mAh battery and power the 9 x 4.5 propellers at 6 amps each. The model could be flown using one battery; however, it needs added weight for balancing, so I used two batteries.
I redrew the plans to use foam instead of balsa. I made the wing in three sections for easier assembly and disassembly.
SPECIFICATIONS
Type: Semiscale amphibian
Skill level: Intermediate
Wingspan: 72 inches
Length: 62 inches
Weight: 9.5 pounds
Wing loading: 23 ounces per square foot
Construction: Foam, balsa, and plywood
Finish: Painted
List of Supplies
Thirteen 20 x 30 x 3/16 (4.5mm to 5mm) foam boards
Foam-safe glue
Eight 1/8 x 1/4 x 36 spruce spars
One 1/32 x 12 x 6 plywood sheet
One 1/8 x 12 x 12 plywood sheet
One 1/16 x 12 x 12 plywood sheet
One 1/4 x 6 x 6 plywood sheet
One 1/4 x 36 x 3 balsa sheet
Six 1/16 x 36 x 3 balsa sheets
One 1/8 x 36 piano wire
Water-based clear Polyurethane sealer
3M 77 contact cement spray
40- and 60-grit sandpaper.
