Another loop, roll and then a plunge earthward into a dive trailing billowing white clouds of
smoke. Perilously close to the ground it pulls out and zooms a few hundred feet into a hammerhead
stall. No, it isn’t Art Scholl performing at a summer airshow, its the C.G. version of his Super
Chipmunk at a R/C fun-fly. We’ve dedicated our model of the Super Chipmunk to the memory of its
designer and creator, Art Scholl. His breathtaking precision aerobatics demonstrated to millions the
safety and grace of disciplined flying.
Our Super Chipmunk’s super-stable, low speed manners let you fly at a crawl and it simply
won’t quit. Bring it in a little nose high, and you’ll still have solid control to a perfect touch-down. Turn
it loose and this performer will put on a airshow with all the flash and flair of the original.
Additional Items Needed:
4-5 channel radio
CA glue and epoxy
.45 to .61 (.90 4-cycle) R/C engine
2-1/4” CGP snap-on spinner
Propellers, fuel tank and tubing to suit engine.
14 running feet of covering material
Paint
One 1-1/4” and two 3-1/4” Wheels
Foam rubber
Optional Wing Flaps:
CG 3/32” Strip Aileron Set
CG True 1/16” pushrods
1/8” x 3” x 6” Aircraft Plywood
Tools & Supplies Needed
Miscellaneous rubber bands
Wax paper
Modeling knife or single edge razor blade
Sandpaper
Pins
Drill sizes:
1/16”, 5/64”, 3/32”, 1/8”, 5/32”, 3/16”, & 1/4”
Flat building board
Pliers
Small Screwdrivers
Iron for applying covering
Masking tape
©Copyright 1988 Carl Goldberg Products Ltd.
CARL GOLDBERG PRODUCTS, LTD.
Super
Chipmunk
Instructions
23456
ASSEMBLING TOOLS
Die- cut beveling tools (from 1/8” ply)
1. First, glue narrow strip to handle, keeping them
square, as shown above left. Then glue wide strip to handle
and narrow strip, again keeping things square.
2. Cut two strips of 100-200 sandpaper to size shown
above. Tack-cement sandpaper to tools as shown.
DIE-CUT SANDING TOOL
1. Glue one strip into handles notches keeping them
square. Then glue remaining strip to other half of handles.
2. Cut one piece of 100-200 grit sandpaper to size of
2-1/4”x3”.
Center 1/4” dowel over grit side of sandpaper. Roll
sandpaper around it as shown above left.
Slide dowel and sandpaper into tool and hold with
rubber band as shown at right. Glue sandpaper to tool.
TAIL ASSEMBLY
The stabilizer and fin are sheeted with 1\16” balsa, and their
interior frames are 3/16” thick balsa. The elevator and rudder
are not sheeted, and their frames are 5/16” balsa. for clarity, the
stabilizer and fin are built first and then the elevator and rudder.
1. Make stabilizer (stab) leading edge (LE.) from 3/16” x
1/2” balsa sticks. Cut balsa carefully to match with plan at
center joint and exact length at tips.
Pin in position, and glue at center joint.
Using die-cut L.E. joiner, center platform, and
3/16”x1/2” balsa, glue outline together.
2. From 1/8” x3/16” strip balsa, cut all trusses to size over
plan. Trim well-don’t force into place. Glue in place.
Let dry thoroughly.
3. Assemble fin in same manner as stab, using die-cut and
stick parts.
4. The die-cut balsa parts for elevator and rudder must be
7
5. Assemble elevator halves and rudder in same manner as
stab and fin, except use 5/16”x1/2” balsa for L.E. and 1/8”
x 5/16” for trusses.
6a. Flush edge of 1/16”x3”x24” balsa sheet even with stab
T.E. and allow a little extra at tip for trim off. Mark sheet
Begin by gluing a 3/16” core between 1/16” top and bottom pieces. In this manner make two elevator tips and two
inner ends as show
Laminate rudder pieces in same manner,.
Laminate center section.
width on stab to show gluing limits.
Remove sheet and apply CA to T.E., tips and trusses.
Turn stab over, position on balsa sheet and press down flat
on table.
Center second sheet under stab L.E. and glue in place.
Cut out center slot in stab platform for fin post.
Carefully trim balsa sheet to match stab outline.
Turn stab upside down and cover other side in same
manner.
6b. Flush balsa sheet with fin L.E. and glue.
Use stab scrap to complete fin sheeting as shown.
Trim sheet to match fin outline.
8
Mark hinge locations for stab and elevator.
Position elevator halves and joiner over plan, and
carefully mark elevator L.E.’s for wire joiner location.
8.Using CG Center-line marker provided, mark center-
lines along edges of parts as shown above. Tilt marker so
guide pegs touch the wood, then lightly pass the marker back
and forth. Point will scribe center line.
9.At locations marked in Step 7, make a slit wide enough
for the JET Hinge to fit into.
IMPORTANT! Although you are installing the hinge
now, the hinges are not permanently installed until after the
model is covered.
12.Using no glue, TEMPORARILY attach elevator to
stab and fin to rudder with hinges in place. Hold parts
together with tape.
First break corners with the sanding block. Then, follow
low with stab sanding tool, rounding off all outside edges
except bottom of fin and rudder. Blend stab and elevator at tip.
Using a sanding block, flat sand stab, elevator, fin and rudder,
smoothing out surfaces.
7. Place fin and rudder over plan and mark hinge
locations.
9
13. Remove tapes and separate elevator and rudder from
stab and fin.
Tape T.E. of elevator and rudder to work surface, using
appropriate beveling tool, sand L.E. to center-line. Turn parts
over and repeat beveling for other side.
14. Using no glue, trial fit elevator halves together with
wire joiner. Carve a radius for better fit at wire bend. Elevator
halves must lie flat on table and L.E.’s must be aligned. Punch
a small pin hole through elevator at rear of joiner hole for glue
squeeze-out. Glue joiner in place.
15. For strength, the elevator joiner areas should be rein
forced with nylon fabric as follows.
Apply a dab of CA to the elevator and press one end
of nylon fabric into it (cover finger with a plastic bag or
similar).
Apply a squiggle of glue to elevator and pull nylon
fabric down into it. Rub nylon into the glue with your finger.
Continue gluing and apply nylon around elevator
front and around to other side. Trim nylon Cut.
Repeat this procedure and apply nylon on other
joiner area.
This completes the tail assembly construction.
10
Wing Assembly
PROCEDURE: The wing panels are assembled bottom side up
and then turned over for joining and finishing.
IMPORTANT! Although the wing is a symmetrical section,
because of internal structure (landing gear and aileron bellcrank
mounts), some ribs are not symmetrical(such as Ribs No.
2,4,7,&8). As an aid for proper rib orientation, the tip spar
notches for some ribs have only been partially laser cut.
IMPORTANT, wing assembly will begin with building a panel
overt the “RIGHT WING” on the full-size plan, later on when
it is turned over, this wing will of course become the left wing.
“Right” or “Left” wing refers to the panel being assembled during that particular step OVER THE PLANS.
Since the wing is built in two halves, and steps 1 to 17 are
repeated in the process, two check boxes are provided with
each of these steps. One for the right wing and one for the left.
1.Position one main spar in place over RIGHT WING (or
LEFT WING) on plan. Align spar at center of wing on plan.
Hold spar in exact position by crosspinning at circled location
on plan. CAUTION: Do not build two RIGHT WINGS!
2a. Lay parts out as shown. Glue plywood rib doubler 3
to rib 3 (IMPORTANT! Position slot in ply doubler at top edge
of rib 3).
DOUBLERS MUST FACE EACH OTHER IN WING.
2B. Lay parts out as shown. Glue plywood rib doubler 5
to rib 5.
2c. Using no glue, place platform ribs 3,9, & 14 on spar at their
respective places over plan (position rib 3 so ply doubler faces towards
rib 4)
Rest notched Trailing Edge (T.E.) on rib platforms
(Important: the T.E. has no notch at one end-this unnotched end must
be at wing center as shown).
Press T.E. on rib 3 then slip ribs 9 & 14 into their respec-
tive notches,. Pin T.E. to ribs and rib platforms to building board. Glue
ribs to T.E. and spar (avoid gluing T.E. to rib platforms).
Face ply doubler 5 towards rib 4
No notch here
Notched
end
Face ply doubler
towards rib 4
location
With landing gear slots facing up, set ribs 4 & 5 in position
(NOTE: rib 5 ply doubler must be facing rib 4).
Working one at a time, glue remaining ribs 2 to 8 & 10 to 15 to
spar and T.E. (NOTE: slots in rib 2 must be towards upper rib edge,
slots in ribs 7&8 must face up towards rear of wing as shown). Hold
each rib straight up as it dries. IMPORTANT: for a warp free straight
wing, make sure T.E. is kept straight and not bowed up or down, shim
with balsa if required.
11
3.Position the Set-Back Gauge (SGB) touching the bot-
tom spar. Touch end of top spar to gauge, and set spar in rib
slots.
True top spar to all ribs.
4.With slot facing out from wing, glue landing gear block
to ribs 3,4,&5.
5a.Drill four 5/64” dia. holes(1/16” will do) at punch-
mark locations through aileron bellcrank mounting plates.
5b.Position aileron mounting plate in rib 7&8 slots, this
part is designed to fit only one way. Glue plate in place.
6a. Pin wing at outside of ribs 2 & 15 and T.E. and
remove pins from interior area of wing.
6b. Align T.E. sheeting with center end of T.E. and adjust sheet
so it is flush along T.E. Glue in place. If sheeting edge is not straight,
let excess hang out over T.E. for trim off later.
6c.Gl ue 3/16”: Sq. x 36” balsa into forward rib notches. Cut to
fit around L.G. mount. Balsa should project out from rib 2 about the
same distance as main spar.
7.An opening for the L.G. mount must be made in the L.E.
sheeting. Begin by aligning 5/65”x3”x36” L.E. sheeting with front
edge of spar and flush with spar end.
Project and mark two lines straight back from the ends of the
L.G. mount and on to the L.E. sheet.
Slide sheeting over to side of L.G. mount. Align sheet with
back of spar and measure and mark the front and rear L.g. block locations. Measure L.G. block locations from the back of the spar.
Cut the opening a little undersize at first and try in place.
Enlarge opening as required for proper fit.
12
8. Tape L.E. sheet in place along back edge of main spar. With
taped edge acting as a hinge, lift sheeting up and apply glue to tops of
all ribs and both spars. A shot of Kicker on the L.E. sheeting will help
set things quickly. Carefully close sheeting and gently press it down
on glued structure beneath. (Moistening the sheeting’s outside surface
can assist in bending it to air foil shape.)
9.Glue laser-cut wing tip sheeting in place.
10. Glue laser-cut tapered L.E. sheet in place.
11.Install Mini-Snaps at both ends of 13-5/8” double threaded
wire rod. About 1/16” of threads should protrude through Mini-Snap.
Insert Mini-Snaps and rod into wing through rib holes just
behind the spar. Temporarily tape Mini-Snap to aileron mount.
12.Glue laser-cut center sheeting in place, trimming to fit as
required.
Allow wing structure to dry thoroughly
13. Remove all pins from wing structure and turn wing upside
down.
Trim excess T.E. sheeting flush with T.E
Position a straight edge along front edge of outer ribs and
mark a cutting guide line on the overhanging sheeting.
Rough trim sheeting overhang to line, leaving about 1/8” of
sheet for final sanding.
Remove platforms from ribs 3,9,& 14.
13
14. Lay out wing supports as shown. glue together.
15.Using wing cradles, support wing and pin in position over
plan.
16.Lay out laser-cut spar webs as shown. Glue spar webs to
front of top and bottom spars.
Glue second torque block to first, making sure to align slots
and angles.
From 1/2”x1/2” triangular balsa, cut reinforcing gussets to fit
as shown. Glue together.
18.Repeat steps 1 to 17 over “LEFT WING”on plan.
19.With left wing on wing supports, pin in place on plan.
Position RIGHT WING in place next to it. Raise RIGHT WING
tip and support it at rib No. 11 using laser-cut gauge. Note; gauge is
shaped to fit under curved L.E. and angled T.E. sheeting. Hold gauge
firmly to the rib by tack-cementing or stationery clamps, clothspins,
etc.
19. Study the entire center joint; all end parts of right wing should
just touch those of the left ( tiny gaps are all right). If the fit between
most parts is a little loose because one part protrudes too much, slightly sand only the protruding part for better fit. When sanding it is better
to take off too little than too much.
14
20a. Pull wing panels slightly apart and slide aileron servo mount
into forward slot in rib No. 2.
FOR FLAPS ONLY. From 1/8” ply (not furnished) cut a flap
servo mount using template on wing plan. Position flap mount in rear
rib No. 2 slot.
20b. Using no glue, temporarily install ply dihedral joiners in left
wing carefully insert them into rib notches. Hold joiners with laser-cut
clamps.
Reposition right wing next to left, engaging joiners and
aileron (and flap) mounts in respective slots in Rib 2. Install joiner
clamps on right wing and make a final check of center joint for good
fit of all parts.
Remove clamps and separate right wing.
Glue joiners to left wing spars, and immediately reinstall
clamps.
Reposition right wing and pin to hold in position at center
joint. Glue joiners in place and hold with clamps.
21. Remove narrow strip at bottom of rib No. 1. Position one half
of one front rib No.1 so one side aligns with center line of wing.
Adjust rib to align with spar center joints. Glue in place. Glue remaining No.1 rib to first rib, making double thickness rib at center joint.
22a.Glue dowel mounting plate to front dihedral joiner.
Glue small filler rib at center joint.
22b.Mark and sand end of 3/4” Sq.x3-5/8” balsa block for
tapered fit with rib front.
22c. Glue block to mounting plate, and lower ribs.
22d.Position remaining small front rib over block and glue in
place.
23a.Position T.E. sheeting on left wing. Trim sheeting to match
center joint. Glue in place.
23b.Following same procedure as step 8, install L.E. sheeting on
left wing.
23c.Install laser-cut tapered L.E. and center sheeting.
24. Repeat step 23 and install top sheeting on right wing.
25.Trim and sand balsa L.E. sheeting flush with rib fronts.
26. Position Balsa L.E. and hold in place with tape as a hinge.
Open and apply CA (Slow dry Thick is good here) to all ribs and
sheeting edges. Fold L.E. back into position.
15
29.Position aileron exit sheeting pieces as shown on plan and glue
in place (run aileron pushrods through slots.)
30.Position pre-cut opening of wing tips face down on flat sand-
paper and wipe lightly a few times. Then, run your finger nail along
edges to remove burrs.
Fit 1/8” balsa rib 16 inside plastic tip. Slide rib towards tip front
and flush it along all edges. Hold rib in position with a few drops of
CA, then apply more along all seams for permanent bond. Repeat for
other tip.
Check fit of tips on wing. Using CA, glue tips in place.
From 5/64”x3/16” strips of balsa, cut cap strips to cover the
exposed edges of all ribs top and bottom. Glue cap strips so they are
centered over each rib.
From the three 24” ailerons provided, choose the better two for
the ailerons, the remaining one to be cut up for inboard T.E.s (and
optional flaps.)
31.For “aileron only” wing cut parts over plan as shown above;
two 24” long ailerons , and two 7-9/16” T.E. inboard sections.
16
For “aileron/flap” wing cut parts as shown: two 19” ailerons,
two 9-1/8” flaps, and two 3-1/4” T.E. inboard center sections. Cut over
plan for exact size.
32. Using the center-line marker, make a center line along entire
length of ailerons, (flaps), and wing T.E.
33.FOR AILERON-ONLY WING, continue with this step, for
FLAP wing proceed directly to Step 34.
Glue inboard T.E. in position as shown above. Proceed to
Step 35.
34.FOR FLAP WING ONLY, cut nylon tubes to 3” length. slide
nylon tube onto aileron horn wire. Repeat for other tube and wire.
Bend one flap horn as shown above. Hold threaded portion of
wire at about a 45 degree angle. Firmly grasp UNTHREADED end of
wire about 1/2” from end of nylon tube and bend wire horizontally 90
degrees. Check on table, adjust as necessary.
Make second flap horn opposite to first by bending
UNTHREADED end as shown above.
File bent ends to a slightly pointed shape for easier mounting of
flaps later.
Using a sharp tool, make 1/16” deep grooves in T.E. and in
inboard sections. Using threaded end of flap wire, file grooves to a
rounded shape so half the nylon tubing will lie recessed in both the
inboard section and the T.E.
Cut two clearance slots about 5/8” from center joint in wing
T.E. and from inner ends of T.E. inboard sections.
Using no glue at first, temporarily place horns in wing grooves,
position both inboard sections and check for horn movement-top to
move about 1” total fore and aft.
Remove T.E. inboard sections, and carefully glue horn wire
tubing and T.E. inboard sections in place (CAUTION: keep glue off
wires).
35.Working over Wing Plan, transfer hinge locations shown on
the plan to aileron (and flap) and wing T.E. When fitting aileron, keep
it centered to allow clearance at ends.
Press flap onto end of flap wire to make a mark, with a small
nail, make a hole for the wire. Work carefully, keeping the hole centered inside the flap. Repeat for the other flap. Work carefully so that
when finished, the threaded ends of horn wires tilt forward evenly with
the flaps in position on pointed wires.
36.Using beveling tool “EA,” bevel front edge of aileron to cen-
terline. Turn aileron over and repeat sanding. Repeat for other aileron.
17
For flaps, follow this instruction carefully. Lay flaps side by
side and upside down as shown. Using sanding tool “RF”, bevel only
the front bottom edge of flaps up to center line (flaps only have to
move one direction-down.
Flaps “up”
Flaps “down”
37.Fill gaps, joints, etc. with a filler appropriate for balsa. Smooth
out with applicator.
38.Using 240 grit sandpaper, flat sand entire wing to blend surfaces
and remove high spots.
39.Apply a dab of CA to wing and stick one end of 3/4” nylon
fabric to it. Let dry until the nylon is glued solidly to the balsa.
Apply a squiggle of CA to wing and pull nylon fabric down
into it. Rub nylon into glue with your finger (cover finger with plastic
bag or similar).
18
Temporarily hook-up the aileron servo to the receiver and bat-
tery, turn R/C system on and with the transmitter aileron stick and trim
tab at neutral, make sure the aileron servo arm is in vertical
position(pointing straight up & down relative to wing).
Position servo inside wing on ply mount, carefully align bell-
crank pushrods with servo arm. Drill holes as required through plastic
mount and screw it to ply mount with #2x3/8” sheet metal screws.
Mount optional flap servo in same manner behind aileron servo
as shown on plan.
3.Connect Mini-Snaps to opposite ends of servo arm. For balanced
aileron movement, check that both aileron bellcranks are parallel to the
wing T.E., make adjustments as required to Mini-Snap connections at
bellcranks.
WHEEL PANTS & LANDING GEAR
1. Rub cut edge of wheel pants over sandpaper and clean burr off
edges.
2.In the bottom of the four pant halves there is a slightly raised
area, this will be removed for the wheel opening. Cut a rough opening
in this area of all four pant halves as shown-but stay about 1/8” in
from raised line.
3.The pants are designed so one half fits inside the other. Position
one pant half (with side slot) inside pant half without slot. Adjust parts
for good fit, with about 1/16” to 1/8” overlap. Glue halves together
with a few drops of CA around seam.
Assemble other pant in same manner.
4.Enlarge rough wheel opening by lightly tracing the raised outline
with a sharp knife. Work slowly, making several passed, making the
cut deeper each time.
5.Glue a pair of half round ply pieces inside pant, on both sides of
slot.
6.Using a 3/16” dia. drill, open hole on side of pant (do not drill
slotted side).
7.Using L.G. axle (longer end) into pant. Axle should protrude out
pant. Position nylon hold-down over wire at pant side as shown.
Mark, drill, and mount with a #2x3/8” sheet metal screw. At side
slotted end, use #2 shoulder screw. If L.G. wire fits loose under holddown, remove L.G. and glue scrap plastic shim in slot. To remove
pant, simply snap hold-down off shoulder screw and rotate it away
from L.G. wire.
Reglue all pant joints using CA. glue.
This completes the wheel pants. They can be used as is and simply
apply decals to them later. Or, if desired, the seams can be filled, sanded smooth and the pants painted.
19
20
FUSELAGE ASSEMBLY
1.Carefully remove all fuselage (fuse) parts from laser-cut sheets.
Lightly sand any rough edges.
2.With side stamped “A” facing out, position two 1/8” ply formers
“A” (firewall) together, matching all edges. To hold them in alignment,
tape them securely together along one edge as shown at right. Have
four ply clamps ready for next operation.
3.Open firewalls and apply a liberal amount of glue to one part as
shown on left.
Keep edges aligned as you close firewalls and tape opposite
edges together, squeeze firewalls together using laser-cut clamps.
When dry, remove clamps and tapes; set clamps aside for use later.
4.Be sure sides are laid down left and right as shown.
Temporarily position fuse doublers on fuse side, checking fit and
placement before gluing.
Glue fuse doublers in place.
5.Position former doubler “AA” on firewall so that mark at top of
firewall is centered in notch in “AA” and match curved edges of parts.
6.Glue ply former doubler “BB” to bottom of former “B”. Hold
until dry with firewall clamps.
From 1/8”x1/2” balsa, cut and glue strips to match formers as
shown. Apply strips as shown below.
At center-punch mark drill a 1/4” hole through former.
21
7.Tack-cement the engine between plastic engine bearers, holding
it vertical and parallel to mounts.
Position engine/mounts on firewall for side mounted or inverted
installation. Center-alignment marks are molded into engine mount
bases; align these marks directly below the engine mounting flanges
with the corresponding laser-marked line on firewall. Then measure
and position mounts so they are equally spaced from second lasermarked line
Mark straight down through holes in mounts.
8.Drill four 5/32” holes at marked locations.
9.Mount propeller and spinner on your engine. Position engine
over fuse top view on plan and compare it to the installation shown.
Back of spinner, should protrude about 1/8” beyond the cowl front as
shown on the plan. Hold engine in this location. For long 4-cycle
engines, check for at least 1/8” clearance between engine rear and firewall; to obtain this clearance the engine may have to be shifted forward as required. Measure the distance from the engine rear to the firewall. Write this measurement down it will be used later for engine
mounting.
10.Position one engine mount, butting its rear flange against the
firewall location shown on the plan. Observe how the front engine
mounting holes relate to the engine mount. If there is at least 1/4” of
mount forward of this hole location, the spacer plate shown on the plan
is not needed and you should proceed directly to step 11. If there is
doubt that the mounts do not project far enough for adequate drilling
and engine mounting, the spacer must be installed by completing the
steps below. (Note for 4-cycle engines, make sure the spacer does not
obstruct the carburetor, cut out spacer center if required for clearance).
Position 1/4”x2-1/8” ply spacer on firewall so that it lies equally
spaced over holes (trace spacer shape on firewall, to check position).
Glue spacer in place.
22
Turn firewall over, at hole locations, drill 5/32” holes through
1/4” spacer plate.
11.Permanently install four blindnuts in back of firewall using
socket head screws and washers to pull blindnuts up into the screw
holes as shown (firewall with spacer plate shown for clarity). Remove
screws after seating blindnuts. Glue blindnut flanges to firewall.
12a.Place fuse sides one on the other, tape rear together around
the back end. Spread fuse fronts apart, and plug former “B”
into holes in body sides (doubler “BB” must face forward). Hold
parts together with a rubber band.
12b.Hold fuse tail ends up, carefully spread fuse rear open, and
plug former “E” in place, hold with a rubber band. Working towards
front, install formers “C” and “D” (balsa doublers facing in towards
each other) in same manner, using rubber bands to hold parts.
12c.With laser-cut separation at tail end facing down, insert top
sheet under rubber bands at former “B”, and work it towards tail, slipping it under bands as you go.
12e.Lock tabs at sides and ends of top sheet into corresponding
notches in fuse sides. Hold parts with tape.
12f.Position bottom sheet in same manner, sliding it towards rear.
13.Install firewall and pull fuse fronts together with tape as shown.
23
14.Place fuse over TOP VIEW on plan sheet. Viewing from above,
carefully align the fuse to match plan outline. If an area of the fuse is
off, adjust that position in the direction required. Tape parts to hold in
position.
15.When satisfied with alignment, permanently glue sides,
formers and sheet parts in place. Apply a bead of CA along
all joints inside and outside, or from both sides.
In the case of formers-it will penetrate the joint and leave a slight
reinforcing fillet.
At tail end, glue bottom sheet to conform to slight bend in fuse
sides.
16.Plug 1/8” laser-cut braces into slotted locations in fuse dou-
blers and glue securely in place.
Position and glue wing mounting blocks. reglue these joints thor-
oughly, the wing attaches here-it must be strong.
From 1/2”x1/2” triangular balsa, cut reinforcing gussets to fit
behind firewall. Glue in place.
17.Set wing in place on fuse, then check and adjust until wing tips
are equidistance from rear end.
Project two lines straight forward from fuse sides on wing bot-
tom.
Position a 1/8” ply bolt plate about 1/8” away from line and so
that laser-marked line is aligned with T.E. joint as shown. Glue in
place. Repeat for second bolt plate.
Measuring carefully 1-7/16” from wing T.E. and 9/16” in from
fuse sides, drill two holes 5/32” dia. down through wing and bolt
mounting blocks.
Glue two large washers at hole locations.
Remove wing from fuse. Install blindnuts in bottom of mounting
blocks, pulling them up in place using screws and washers.
Install wing using bolts. Check alignment of wing and fuse at
front. At hole in former “B”, drill a 1/4” dia. hole about 3” deep into
wing (try to hold drill square and level into wing).
Cut 1/4”x4-1/2” dowel to 3” length. Remove wing and glue this
dowel securely into wing, leaving about 1/4” protruding.
24
18.With laser-cut separation facing out, bend and position front
bottom sheeting. Glue in place.
19.Trial fit the tail wheel bracket at laser-cut separation in bottom
sheet. Using a knife or small saw, make a slot for bracket flange as
required for correct fit. DO NOT GLUE bracket in place at this time!
20a.Cut wing fairings from vac-formed sheets and try fitting
them at L.E. and T.E. Cut out bottom of fairing holes and trim hole
walls to match washers. Position fairings for best fit with fuse and glue
to wing.
20b.From scrap 1/8” balsa, glue and trim lower tail end sheeting.
21.Install top formers “TA”, “TB”, “TC”, “TD” and “TE” in their
respective slots in top fuse top (IMPORTANT: tilt formers TB and TC
using gauge “TBTC” as shown below).
22.A 1/8” square balsa strip must be glued to the fuselage top to
serve as a gluing brace for the top sheeting. Since the front sheeting is
thicker than the rear, the front strips are spaced differently than the
rear as described below.
From 1/8” square balsa strip cut two pieces to fit from bottom
notch in former “TC” to “TE”. Keeping strips about 1/16” in from and
parallel to fuse edge, glue to top.
Install remaining 1/8” balsa strip in bottom notches in former
“TC” forward to firewall-position this strip 1/8” in from fuse side.
23.From 1/4” square balsa cut and glue three top sheeting sup-
ports to fit notches in formers “TC”, “TD”, and “TE”.
Cut three more supports and glue to notches in forward formers
“TB”, “TA” and firewall.
24.The three rear sheeting pieces are oversize wedge shapes and
are designed to be shifted back and forth for best fit.
Begin sheeting installation with one side. Slide sheet in position
so lower edge butts against fuse side and upper edge fits about centered
on 1/4” balsa support. When satisfied with fit, glue sheet in place
(slight dampening of outer balsa surface will help curve it to fit fuse
shape).
Install opposite side sheet in same manner. Trim sheets flush
with front of former “TC” and rear of “TE”.
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Slide top center sheet in position and glue in place. Trim to fit
with side sheets.
25.Install 1/8” laser-cut front sheeting in dame manner, applying
side pieces first. Where 1/8” balsa butts against former “TC” glue a
scrap of 1/8” sq. inside to reinforce the joint.
26.Flat sand fuse and round off corners, except the following
areas: top of tail mounting area, and wing saddle-repeat: do not sand
these areas, except very lightly to remove burrs.
27.Carefully remove scrap areas from formed cockpit as shown
above.
Gently bend cockpit front, rear, and sides along formed seams-
do not bend sharp or plastic will crack.
Temporarily place cockpit inside fuse, trimming as required for
good fit.
Remove cockpit and set aside for painting.
28.Bolt wing in place.
Center stab on fuse, measuring to obtain equal distance from
side to side, and from nose of fuse to rear corner of each stab tip. View
from rear to make sure that stab is level in respect to wing.
Trial fit fin in place, making sure that it points dead straight
ahead.
When tail parts are aligned and square with fuse, make several
reference marks. Remove fin and stab.
Using slow CA or epoxy, glue stab and fin in place. While dry-
ing, check parts for square and alignment.
Glue balsa filler pieces to fuse at front of stab.
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29.Cut 7/8” sq.x16” balsa block into two 8’ pieces. Then, taper
sand to pointed fairing shape as shown in photos above and fuse views
on plan.
Glue fairings in place.
30.Refer to fuse views on plan for installation of rudder pushrod
guide tube through balsa fairing. Using a sharpened 1/8” wire, drill a
hole for the rudder pushrod guide tube through balsa fairing and former “TE”.
Position nylon rudder and elevator guide tubes in fuse as
shown on plan (insert long threaded rods to hold tubes straight). Glue
nylon tubes in place where they exit fuse rear. From scrap ply, cut
braces to support tubes at formers “C” to “D”. Glue tubes to former
“C”.
Remove wire rids and trim nylon tubes flush where they exit
fuselage at rear.
Later, when installing your radio equipment , we recommend
running the receiver antenna into the rear of the fuse. To make this
easier to do, glue a length of plastic tubing, drinking straws, etc. from
former “C” to “E”.
To protect the engine area from becoming oil soaked, it needs
to be “fuel-proofed”. Either polyurethane, CA, or epoxy is good for
this. Apply your fuel proofer to entire engine area, firewall, sides and
fuse front. Open up screw holes with toothpick while paint is wet. Let
dry thoroughly.
COWL ASSEMBLY
1.Using the measurement from step 9, position and tack-cement
engine on mounts (engine must parallel mounts and point straight out
from firewall).
Carefully mark through engine mounting holes to mounts.
Remove engine. Drill four 1/8” holes straight into and through
mounts.
Install engine, muffler, and propeller and spinner.
#6 x 3/4” screws
2a.Cut cowl halves apart at center. Trim to match formed curved
lines as shown in photo above.
b.Cut out opening for prop shaft and front air intakes.
c.Try fitting cowl half in position over engine (allow about 1/8”
space between cowl and spinner). Observe and mark where openings
must be made in cowl for engine/muffler clearance. Begin making
these openings, cut a little at a time, trying and fitting and enlarging
openings as needed. Do not try to rush this or you may ruin the cowl or
worse yet cut yourself.
Try fitting other cowl half in place, cutting openings for
engine/muffler as required.
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d.When both cowl halves fit around engine, tape them together at
center joint. Check for overall fit of cowl, match-up with spinner, etc.
If cowls must be overlapped to fit, mark and trim the overlap until
both halves butt fit at center joint.
From long plastic strip furnished, cut and glue a joining tab
along the inside edge of one cowl half as shown.
Lower strip must be cut into small segments in order to fit around
curves.
e.Glue cowl halves together.
Attach cowl to fuse using #2 x 3/8” screws and washers. At
lower side screw locations, make spacers from scrap ply to fill gap
between cowl and fuse. Glue spacers to fuse sides.
IV COVERING
General. A good covering job should be preceded by careful sanding,
filling nicks and dents, then more sanding. Use filler appropriate for
balsa such as CG Model Mate. Any irregularities in the wood surface
will show on the covering so a smooth sanding job is a must for good
appearance. For final sanding, use fine sandpaper (grade 240 to 320)
and a sandpaper block.
As mentioned earlier, the easiest way to finish your Chipmunk is to
cover it in one color and then either paint it or apply the color scheme
cut from covering material. Follow the manufacturer’s instructions
regarding applying multiple color paint schemes. If painting the color
scheme, polyurethane spray paint is recommended.
Now is a good time to paint the cowl and canopy frame detail so they
can be set aside to dry while you are covering the airframe. Cowl
should be sanded smooth and joints filled with material suitable for
plastic. ‘Wipe down completely with a tack rag to remove all dust.
Mask areas to be painted.
IMPORTANT! Raw fuel and engine oil residue, if allowed to puddle
or stand, can eventually deteriorate the finish, resulting in loose edges
of the covering and striping, peeling paint, etc. Wiping the model
down after each flight will help maintain your plane’s finish for years.
Engine exhaust often affects details such as striping, etc. Careful
applications of CA along the edges will hold them down securely in
place.
Read instructions on paint can, and follow them. The first coat
should be applied very lightly. Do not try to cover in just one coat or
the paint will run! Repeat applications, gradually building up color
density while allowing time between coats as specified by the paint
manufacturer. Let final coat set a bit, then remove the masking tape
carefully. Set aside away from your work area so it can dry free from
dust or other damage.
PAINTING PLASTIC FILMS. Modeling grade polyurethane or
epoxy paints are recommended. To assure good paint adhesion to the
plastic covering, the area to be painted should be washed with soap
and water to remove surface grease and oil. Then dry thoroughly. You
can also clean the surface with acetone. The design is then carefully
masked; vinyl tape is best for this. Optional: gently wipe masked area
with 000 steel wool to dull plastic surface for increased paint adhesion, being careful not to disturb the masking tape.
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