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/ Model Kits / Free Flight
Rubber Powered Airplane Kits / FF-59 RAF SE5
/ Gasoline Conversion of FF59 SE5
Kit FF59 Royal Aircraft Factory SE5: Gasoline
Conversion Using
a O.S. .20 Four-Stroke Engine.
Written by Sam in Arizona, June 24, 1996
Sirs:
I have just returned from the test flight of my latest Easy Built
kit a 50" wingspan R.A.F. SE-5 (kit FF59). This is my second
kit from your company. My first was a Jodel D-9, 50” wingspan originally
designed for electric flight. I powered it with an O.S. .20 four-stroke
engine, cut ailerons into wing and used standard servos. It flew well,
but was grossly overpowered. A low-speed, low-altitude accident ended
it’s career early. Only later did I learn an incorrect wing incidence
setting was to blame for its vicious stall characteristics, not the
kit design. Recently, I happened upon an advertisement in one of the
model magazines advertising a 50" wingspan, jumbo free flight
SE-5. Out of curiosity, I ordered one, knowing full well that this
aircraft was close in size to a Sopwith Camel F-1 I had built about
10 years ago. The Camel was powered by a .91 four-stroke, covered
with silk and dope, and flew quite realistically.
After receiving my Easy Built kit FF59 of the SE-5, I sat down at
my computer and fed in some numbers. The weight, wing area, power,
and construction looked like it should fly with the same O.S. .20
four-stroke engine that overpowered the Jodel D-9.
I started off with a light-ply box that tied the engine, landing gear,
wing, and Cabane struts together. Then I built the plane around the
box, exactly as the plans show. Of course, I had to add some spars
to the wings that also serve as anchors for the ailerons. The leading
edges of the wings are 3/16" hardwood dowels, and the main spars
are spruce. Cabane struts are streamlined aluminum tubing, and the
wing struts and landing gear are also spruce, the same size as shown
on the plans. This proved to be quite strong and for safety, I added
aramid-kevlar cables for bracing, these are also adjustable for rigging.
The plane was rigged with all surfaces and the engine at 0° to the
datum line of the fuselage. I later rigged the upper wing at 2 ½°+
to improve the stall characteristics. After my first test flight,
I have found it necessary to add 4° downthrust to the engine.
The plane was covered with the silkspan tissue that came with the
kit, it appears to be a very high quality covering. Three coats of
clear nitrate dope and two coats of colored butyrate dope gave the
structure surprising structural and torsional strength. I am presently
hand-painting the various roundels, numbers, and insignia. The instrument
panel was used as a model to fabricate one on my computer using photographs
of the instruments, gages, and controls. Then they were printed on
glossy paper and fuel-proofed. The control system was made up of aramid-kevlar
cables routed over pulleys and fairheads duplicating that of the original
aircraft. The aircraft flies quite smoothly and realistically with
the O.S. .20 four-stroke turning an APC 11x4 propeller with no tendency
to tip-stall or any other nasty traits associated with biplanes.
The only thing that put me off at first was the lack of die-cutting.
But, I've seen some really good kits that were all but ruined with
bad die-crushing. I have three models partly built because the die-cut
parts were unusable. Cutting printwood is not difficult if one takes
his time. Laser cutting would be ideal, but costly. I think maybe
printwood was actually an advantage in a kit-bash since many parts
were modified before they were cut out saving wood in the process.
I will always have something good to say about Easy Built Models and
I will heartily recommend them to anyone wanting a challenging, well
designed model kit.
Thanks again for a very good kit design. I will keep in touch.
Sincerely,
Sam | |
