M. K. Bengtson Fokker DVIII 55” User manual

Fokker DVIII 55”
Copyright© 2006-11 M. K. Bengtson All Rights Reserved Rev 07/11
Fokker DVIII 55”
R/C Scale Model Instructions
CONTACT INFORMATION
The Fokker DVIII was designed by M.K. Bengtson
Prototype by Edi Werner
Manufactured and Distributed by:
Bengtson Company
e-mail: [email protected]
Web Site: www.aerodromerc.com

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Copyright© 2006-11 M. K. Bengtson All Rights Reserved Rev 07/11
Fokker DVIII 55”
Thank you for purchasing the Fokker DVIII model for electric
flight.
THE MODEL
A semi scale adaptation of the Fokker DVIII, this model is
designed to be easy to build and exciting to fly.
Finished Model
POWER SET UP
The model can be set up to be powered by the AXI 2826 with
and a 14x7 prop.
R/C GEAR
A four function mini receiver and four micro servos are all that are
required.
Model Specifications
Wingspan: 55"
Weight: ~48 Oz. (The design was considerably lightened recently)
Power System: AXI 2820 or 2826
Prop: 14x7 prop
R/E/A/T: 4 servos Ailerons, Rudder and Elevator.
Covering: Balsa and Litespan or Polyspan covering
Wheels: Balsa, plywood, Neoprene foam cord tires, Brass tube
hub. Paper card wheel cones
BUILDING THE MODEL
Before Starting
A note about the photos: The photos were taken of a prototype
and the parts supplied may look slightly different from them.
However, the concepts illustrated are the same.
The Fokker DVIII prototype was built by Edi Werner.
COWLING
Begin construction of the cowl by gluing C1 and C2 to a strip of
1/32” ply with the grain of the plywood running the short way.
Basswood may be substituted for the 1/32” plywood. Side and
top balsa cowl spacers fit into 1/4” sq. holes in C1 and C2 to align
the two-ply semi-rings. Glue three's C3's together with C4 and
glue this assembly to the C1/C2 assembly and sand to shape.
The etchings on C4 serve as guidelines as to where to stop
sanding.
Cowling Construction Detail
Cowling Construction Detail
WINGS
Wing Construction
Pin down, over the plan, the pre cut trailing edge plywood, spars
and wing tip, gluing as required. Add the pre cut leading edge
stock. Use 3/16" Sq. balsa spars. Laser cut shear webs are
provided to lean all ribs in the correct orientation and provide
exceptional strength to the wing.

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Copyright© 2006-11 M. K. Bengtson All Rights Reserved Rev 07/11
Wing Construction Detail
Build center wing section separately and without top spars.
Outer panel R2 angle gauge is used to lean rib R2 on outer panel
towards wing tip
Two laminations of 1/16” plywood for wing brace. Add to center
section during assembly. Slide outer wing panels over the ends
when joining.
Front and rear 1/16” vertical grain shear webs are pre-cut and
labelled as the ribs they are to fit between.
The top front section of the wing has 1/16" balsa top sheeting.
When joining the wing panels to the center section, raise up each
panel 1 3/4" at locations shown on the plan. Join top spars and
glue in place. Sand the leading edge stock to be rounded and
meet the ribs.
Wing Construction Detail
1/32” Plywood trailing edge is used on top and bottom of each rib.
The Ailerons are driven by in wing servos and controlled by a
single channel using a “Y” connector. The ailerons are formed by
a laser cut sheet of balsa and reinforced with small riblets. Mount
4-40 blind nuts in 1/8" Plywood mounts for wing attachment
points.
The Leading Edge Of The Aileron
The leading edge of the aileron is rounded over with sandpaper
to make the aileron movable with a minimum gap. The trailing
edge of the wing in that section is left flat.
Aileron Construction Detail
FUSELAGE CONSTRUCTION
The fuselage is built as two separate box structures, the front
balsa sheet and ply area and the rear built up section, which are

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Copyright© 2006-11 M. K. Bengtson All Rights Reserved Rev 07/11
then joined over the plan. This system not only keeps each stage
simple, but it also helps to ensure a straight fuselage.
Building of the rear of the Fuselage
Begin by building two rear fuselage frames over the plan and
allow to dry. Select hard balsa or basswood for the longerons.
Join the two frames over the plan with cross braces and the tail
skid mount. Use elastic cord or a spring to make the tail skid
shock absorber.
Check, check and check again that this and ALL other structures
remain perfectly straight and square.
Building of the front of the Fuselage
The front half of the fuselage is a box structure made from 1/8”
balsa and plywood. Assemble the balsa sides from the two laser
cut pieces. Add the 1/32” plywood doubler to the inside surfaces.
Laminate with a heavy weight when performing this step with
water based glues so that the ply will not warp the balsa side as
the glue dries. Using the plan as a guide, build the fuselage over
the top view adding the sides to the F1, F1C, F2 and F3 formers.
When secure, remove from plan and add the bass mounts.
Fuselage Construction Detail
Cabane and LG bass mounts are constructed from 1/8” sq. and
1/8”x3/8” bass wood with epoxied brass tubing bushings. Two
diameters of tubing are used in the cabane mounts. The outer is
1/8” brass tubing and the inner is a 3/32” brass tubing shim.
During assembly, the tubing and 1/16” music wire are fused in
place with thin CA. For the landing gear mounts, some additional
1/8”x1/4” stock is used and the inner brass tubing is omitted. This
omission is because the landing gear music wire is 3/32”
diameter. Again the LG music wires are fused in place inside the
tubing with thin CA.
1/32” plywood side cheeks are attached before the front cabane
music wire is glued in place as the wire must pass through a
small hole in the side cheek. Side keel K2 and formers K3, K4
support the cheek which is attached at F1c
Fuselage Construction Detail
The top deck formers F1a, F1b F2a and F3a are added and the
turtle decking balsa provided is glued in place. 1/16th Balsa
sheeting covers the front/top of the fuselage between formers F1
and F3.
TAIL SURFACES
Lay out and glue parts of the tail surfaces on the plans.
Don’t add the horns or hinge the surfaces until after covering is
complete.
Tail Surfaces Construction Detail

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Copyright© 2006-11 M. K. Bengtson All Rights Reserved Rev 07/11
Tail Surfaces Construction Detail
LANDING GEAR
The landing gear is made from 3/32”” music wire, bent as
shown on the plan.
Landing Gear Construction Detail
UNDERWING
The underwing is built around the axle with a 1/16” balsa top and
a 1/32” ply bottom with etchings to place internal ribs. Use the
plywood fairings to mount the underwing and as a guide to set
the incidence correctly. The underwing adds some lift to the
model in flight.
Underwing Construction Detail
Landing Gear Detail
COVERING
Any lightweight covering material can be used. Polyspan with
dope or Minwax Polycrylic makes a good choice, Litespan is also
popular.
Decal outlines for this model are available on
www.aerodromerc.com/decals in Adobe Acrobat®pdf format for
printing out on decal paper. Contact paper used for kitchen shelf
lining makes excellent decals. Print out the decal on paper, glue
with a glue stick to the paper backing on the shelf paper, and cut
the decal out with an Exacto knife or micro scissors. Peel off the
paper and adhere to your model. Use black material for the
crosses and white for the backgrounds.
WHEELS
Gluing the ply sides on the laminated balsa core makes the basis
for the wheels. Use the brass hub for alignment. Epoxy the hubs
in place and add a sufficient amount of epoxy around the base of
the hub to reinforce the connection of the hub to the ply. Plywood