T&J Monocoupe 90A Assembly Instructions Manual

T&J Models

R/C Model Designs By Jim Young

9356 Wendover Ct.

Brighton, MI 48116

www.tnjmodels.rchomepage.com

Monocoupe 90A

Speed and Comfort for the Common Man

In the late 19020’s , Don A. Luscombe’s Monocoupe introduced affordable and
convenient performance to the light airplane market. Previously, this market was
dominated by large, expensive, open-cockpit biplanes. The Monocoupe was compact and
offered a closed cabin for comfort and convenience. The reverse curve of the fuselage
became one of the signature characteristics of this family of sporty planes. Much lighter
and cleaner than other aircraft of the time, the Monocoupes were also popular for racing.
The longer and wider Model 90 was introduced in 1930, the A version having a 90hp
Lambert R-266 radial engine.

Our Monocoupe is designed for a 30mm outrunner and 3S 3300mAhr flight pack.
Extensive use of laser cutting and self aligning structure provides a straight and light
airframe with operational flaps.

Copyright © 2015 Jim Young and T&J Models

Monocoupe 90A

Construction

All of short kits require some level of
modeling and flying experience. We do
not recommend them as a first model to
build or fly.

Additional Materials

The following materials are required to
complete this short kit (list may not be
complete):

(4) 1/16”x3”x36” Balsa Sheet
(2) 1/4” Sq.x48” Balsa
(3+) 1/4” Sq.x36” Balsa
(2) 1/4"x1/2”x36” Balsa
(8) 1/8”x 1/4"x36” Spruce or Basswood
(?) 1/8” Sq.x36” Balsa
(2) 1/8”x3”x36” Balsa
(1?) 3/16” x36” Spruce Dowel

Hardware:

2.75” Light Wheels
Wheel Pant Mounting Hardware
(20) #2 x 3/8” Wood Screws
(4) Robart Medium Hinge Points
1/16” dia. Music Wire
5/32” dia. x 36” Music Wire
1/8” dia. x 36” Music Wire

Initial Preparation

Laminate 4 layers of 1/16” balsa for the
stabilizer and fin outlines. The finished
laminations should be 1/8” thick.

Laminate 4 layers of 1/16” balsa for the
wing tips. The finished laminations
should be approximately 1/2” thick at
the L.E. and may taper to the T.E.

Laminate two sets of main and rear spar
joiners from 1/16” plywood. Mark the
location of R3 on the joiners.

Laminate the strut mount doublers to the
strut mount F10. Glue a 3/16” diameter
magnet into the hole in one of the
doublers.

Laminate the two 1/16” plywood FWs
together.

Tail Feathers

The center of the stab and base of the fin
are laser cut. Note that the L.E. of the
fin is offset to the left to give some right
rudder, so make sure the center of the
stab is oriented correctly. Frame up the
stab and fin over the plans with 1/8”
thick stock as shown on the plans. Add
1/32” balsa to the L.E. of the stab and
cap strip the structures with 1/32” balsa.

Page 2 Copyright © 2016 Jim Young and T& J Models

Monocoupe 90A

Flip the structures over and cap the other
side with 1/32” balsa. The rudder and
elevator L.E. dowels can be substituted
with rectangular stock for non-scale
hinges.

Glue the 1/16” plywood control horn in
place. Sand the edges round and
temporarily hinge the control surfaces.

Wings

Cut 1/8”x1/4" spruce main spars and
rear spars to length. If you have a
warped spar, use it for the bottom spar
with the warp curving up. Make left and
right spar assemblies with the spar
joiners glued between the spars. For the
right wing, the joiners should be toward
the L.E. and for the left wing the joiners
should be toward the T.E.

Locate the spar assemblies over the
plans. The bottom main spar will be
slightly off the board, so just pin it to
hold it in position. Use the dihedral
gauge to set the angle of R3 and glue in
place. Glue the remaining ribs in place
using the flap and aileron mounts to
space the R6’s and R9’s. Glue the 1/4”
balsa L.E. in place. The 1/8” balsa T.E.
is square to the board from R3 to R8,
and then angled from R8 to the wing tip.

Add balsa gussets as shown on the plans.
Cut and glue vertical grain sheer webs
between the top and bottom main spars
from R6 to the second R9. Trim the
laminated wing tip to fit and glue in
place. Glue the top sheeting as shown
on the plans. Cap strip the ribs and T.E.
with 1/16”x1/8” balsa.

Page 3 Copyright © 2016 Jim Young and T& J Models

Monocoupe 90A

Repeat for the other wing.

The flap and aileron T.E. are 1/16”
basswood. Pin the flap and aileron T.E.
in place. Cut 1/16” cap strips and glue
to the T.E. For the aileron, prop up the
tip at R11 and R12. Glue the 1/8” balsa
flap and aileron L.E. in place. Add the
flap and aileron ribs, and cap them with
1/16” balsa. Remove the flap and
aileron from the board and glue the
1/16” plywood control horns in place
with 1/8” ribs on each side.

The flaps are hinged on the bottom with
the covering material, and the ailerons
are hinged along the top.

Fuselage

Prepare the top and bottom stringers as
shown on the plans. A separate drawing
of the right side is included so you can
build both sides at once. Using the
fuselage angle gauge, pin F5, F6, F7 and
F8 over the plans. The formers should
angle forward. Glue the 1/4” square and
1/8”x1/4” balsa stringers to the notches
in each former leaving them long enough
to reach forward of F4. Cut and glue
1/8” square balsa cross bracing as shown
on the plans. The cross bracing should
butt up to each former and be glued to
each stringer it crosses.

Page 4 Copyright © 2016 Jim Young and T& J Models