Monocoupe
90 AF
BY LESLIE M. ADAMS
Tired of contest models? Get away from it all with this swell flying scale version of
the latest Monocoupe. Its appearance will satisfy even most exacting scale fiend.
Can you tell her from the real thing? Note how the
Monocoupe corporation has redesigned the 90 AF for the
Franklin 90 h.p. flat opposed engine, giving cleaner lines.
LAST year the Monocoupe Airplane &
Engine Corp. moved its factory from Robertson,
Missouri, to Orlando, Florida. In keeping with the
fine line of aircraft manufactured in the past, a new
member has been recently added to the family -- the
model 90 AF. This new model is powered with the
Franklin 90 h.p. flat opposed engine. Electric starter
and generator is standard equipment. The interior of
the cabin has been cleaned up to a point where the
appearance is that of a new car. No push-rods to get
in the way. All are buried under the floor hoards. The
cowlings have all been refined, resulting in cleaner
lines and greatly increased visibility for both the pilot
and passenger.
As is shown in the photographs, this model is
not the usual type of flying scale model where all
except the general outlines are scattered to the four
winds. For general sport, exhibition or precision
flying; a good scale model is hard to beat. To date,
this one has had over sixty flights with a total damage
of two props and the fairing cracked off the landing
The construction is no more difficult than the
ordinary gas buggy. Special designed nose will
knock out in case of a hard landing, thus saving
engine casualties.
gear. The ship is built to a scale of one and one half
inches to the foot. The only deviation from scale is
the slight enlargement of the tail group, increase in
wing dihedral, and removable wings and tail. From
the, firewall to the tail post the fuselage has all the
members that the large ship has.
Well, fellas, open that can of glue and start in.
Make the two sides of the fuselage first, the
top from T-3 to the tail post, the bottom from B-1 to
the tail post. At the junctions B-2 and at T-2 and at B5 only a tack cement joint is made. This is because
when the two sides are assembled with the cross
members these points are spread beyond the normal
widths of the longerons.
In assembling the two sides the tail post is
fastened together and spreader pieces at stations T-3
and B-3 are installed first. Work from here to the tail
post. Put in cross members at B-1. The vertical
members come to a point at T-1. The top windshield
members from T-1 to T-3 are added at this time.
Note: The top longerons are straight from T-3 to T.5.
Be sure that station T-1, B-1 is perpendicular to this
top line. The top and bottom diagonal members are
added checking the alignment as they are installed.
The landing gear is on 1/16" music wire and is
bound to the cross members and longerons at B-3 and
B-4. A medium-sized thrust bearing is bound and
soldered to the rear landing gear strut 1/4" from the
longerons. This is the lower attachment for the wing
struts.
The fuselage fairing is next. Cement the
firewall FF to the members at station B-1, T-1. The
door frame
is made of four pieces of 1/32 x 1/8" balsa strips.
These are cemented together and while wet, bend to
outline shape and let dry. It is best to fasten these in
place right on the fuselage sides. The top and back
sides of the door frames are of 3/32 x ?/8" balsa. The
top continues back to T-5. The door is made the same
way right in the door frame. The instrument panel is
installed and the lower windshield outline is cemented
in place. This outline is of 1/16" diameter bamboo. A
short curved bamboo brace from the outline to the
instrument panel is added one inch on each side of the
center line of the fuselage. Short stringers are installed on the sides from the firewall to the door
frames. The stringers on the sides of the fuselage are
of 1/16 x 3/16". A 1/8" square stringer is added to the
lower side below the door from the firewall to B-7.
The window outline (rear) is of 1/16" sheet. Two
stringers are installed on the top equally spaced from
station T-5 to one half inch ahead of T-8. Location of
the bottom stringers shown on the former FF-1. The
side stringers shown on this former join the lower side
stringers at B-7. The longerons are faired as shown in
the drawing. Top from T-5 to T-8 and the bottom B-7
to the tail post. 1/16" square stringers are cemented to
the longerons and 1/64" sheet is bent over the
longerons. See cross-section of longeron detail in the
drawing. Cover the front part of the fuselage with
1/32" sheet.
The tail. skid is two pieces of 1/16 x 3/16"
bamboo. It fits on top of the cross brace at station B11 and in a slot at the bottom of the tail post.
The stabilizer mount platform is of 1/16"
plywood. Use plenty of cement.
The landing gear is faired as indicated in the
drawing. Front fairing 3/16" square balsa. Rear
fairing 3/16 x 3/8" balsa. A top rib is of 1/8" sheet.
Bottom also 1/8" sheet.
The motor mount is a set. of standard
aluminum mounts. Bolt to the firewall. The motor is
set at minus one degree. No side offset is used.
The motor cowling is built around the motor.
Space the ring C-2 1/8" from the firewall. Use spacers
and cement in place in a manner that can be cut loose
later. Mount the motor. Carve the front block to shape
and fasten to former C-2 with the 1/8 x 1/4" side
spacers and the 1/8" sheet former on the bottom.
Plank the
cowling with 3/32 x 3/8" balsa. Be sure to leave an
opening around the cylinder of the motor large
enough to slide the cowl up and over the motor when
removing or putting the cowl on. The cowling is held
in place with four cowl clips, as shown in the drawing.
The tail planes are of the usual construction
except the outline which is made of laminated strips
in the same manner as described in the building of the
door frames. The fin-rudder assembly is cemented to
the stabilizer-elevator assembly. The fin is offset
1/16" as shown in the drawing.
The wing construction is standard practice.
The wing section is the Clark-Y. Rib spacing is to
scale. Thirty ribs are required from 1/32" sheet. The
leading edge is 1/4" square. Front spar 1/8 x 5/8" and
the rear spar 1/8 x 1/2". The trailing edge is 3/16 x
1/2". The wing tips are laminated. Six plys of 1/32 x
1/4" balsa. The spars are spliced and the dihedral built
in before the wing is assembled. A reinforcing piece
is added to the spars at the splice. This reinforcement
piece is of 1/32" birch plywood. Use plenty of cement
and bind with thread. Assemble the center section
first. Then the outboard panels, first one side then the
other. The tip ribs are standard ribs clipped. These are
shaped after the tips are installed. Cover the leading
edge top and bottom with 1/32" sheet. All ribs are
capped with 1/32 x 3/32" balsa top and bottom.
The struts are "tailor made." Mount the wing
on the model and build the struts to fit.
Cover the entire model. The original was
covered with silk but with present conditions, the silk
supply. may be --? So Silkspan or bamboo paper are
the next best thing.
The original model was painted in the same
manner as the large ship. Loning Yellow with Fokker
Red trim. Berryloid pigment dope was used. Three
coats of clear dope. One silver priming coat. Sand
slightly at this point. Six spray coats of Loning
Yellow. Mask off all lettering and strips and give
these portions of the model three coats of Fokker Red
(over the yellow). When. dry, remove the tape.
Water-sand with #400 wet or dry sandpaper, finishing
with a good grade of rubbing compound. Install
windshield and windows at this point.
Install coil, battery box and timer in positions
so as to balance the model approximately three and
one half inches from the leading edge of the wing.
Glide the model several times over tall grass and
check the balance. Make any adjustments by adding
weight to the nose or the tail as the case may be.
The original model weighed twenty-four
ounces with an Ohlsson "23" installed. The model has
been flown with both an Ohlsson "23" and a Forster
"29."
Well, fellas, happy landings!
BILL OF MATERIALS
For Flying scale model of Monocoupe
90 AF.
Fuselage
8 pcs.
1 pc.
3 pcs.
10 pcs.
2 pcs.
1 pc.
1 pc.
1 pc.
2 pcs.
8 pcs.
1 set
1 pc.
1 pc.
2 pcs.
1 pc.
3 pcs.
3 feet
2 pcs.
2 pcs.
1 pc.
1 pr.
1
3/16 x 3/16 x 36" balsa.
1/16 x 2 x 8" balsa.
3/32 x 1/8 x 24" balsa.
1/16 x 3/16 x 18" balsa.
1/16 x 2 x 24" balsa.
1/16 x 1/4" bamboo.
1/8" dowel.
1/16" mahogany plywood.
1/64 x 2 x 18" balsa.
1/16 x 1/16 x 18" balsa.
aluminum motor mounts.
3/4 x 2-3/8 x 4-3/8" balsa.
1/16 x 2 x 36" balsa.
1/8 x 1/4 x 3" balsa.
1/8 x 1/2 x 3" balsa.
3/32 x 3/8 x 24" balsa.
1/16 music wire.
3/16 x 3/16 x 4" balsa.
3/16 x 3/s x 4" balsa.
1/8 x 2 x 3" balsa.
2-3/8" M & M airwheels.
1/2" wheel.
Longerons, etc.
Formers.
Diagonals top and bottom.
Stringers.
Covering front part of fuselage.
Windshield and tail skid.
Wing and tail rubber band attachment point.
Firewall and stabilizer platform. 4 x 5".
Longeron fairing.
Longeron fairing.
Nose cowl block.
Cowl former C-1.
Spacer nose block to former C-1.
Spacer nose black to former C-1.
Cowling planking.
Landing gear.
Front landing-gear fairing.
Rear landing-gear fairing.
Top and bottom landing-gear fairing.
Tail wheel. From toy car.
Tail planes
1 pc.
3 pcs.
10 pcs.
4 pcs.
1 pc.
1/4 x 1/4 x 24" balsa.
3/32 x 1/4 x 36" balsa.
1/32 x 3/16 x 36" balsa.
1/32 x 1/2 x 10" balsa.
1/8 x 1/8 x 6" balsa.
Spars.
Ribs.
Outline.
Stabilizer leading edge covering.
Fin diagonal.
Wing
3 pcs.
2 pcs.
7 pcs.
2 pcs.
2 pcs.
2 pcs.
20 pcs.
6 pcs.
1 pc.
1/32 x 2 x 36" balsa.
1/4 x 1/4 x 36" balsa.
3/16 x 1/2 x 36" balsa.
1/8 x 5/8 x 36" balsa.
1/8 x 1/2 x 36" balsa.
1/32 x 2 x 36" balsa.
1/32 x 3/32 x 24" balsa.
1/32 x 1/4 x 36" balsa.
1/32" birch plywood.
Ribs.
Leading edge.
Trailing edge and struts.
Front spar.
Rear spar.
Covering leading edge.
rib cap strips.
Wing tips.
Dihedral reinforcement. 2 x 8".
Miscellaneous
.010 celluloid
1-1/8 yds.
18
18
2 ft.
1 pt.
1 pt.
1 pt.
1/4 pt.
windows.
silk or equivalent.
1/4" washers.
medium sized thrust bearings.
.016 music wire.
cement.
clear dope.
Loning Yellow pigment dope.
Fokker Red pigment dope.
Scanned From October 1942
Air Trails