Old School Model Works Comet Instructions for use

CONSTRUCTION MANUAL
www.oldschoolmodels.com
Using the Manual
Be sure to read each step thoroughly before you start
the step. Test-fit the parts together to make sure they fit
properly. If necessary trim to fit.
Beside each step you will notice a check box (or two).
These are so you can keep track of your progress while
building your kit. For steps that have two boxes, as in the
construction of the left and right wing halves, these steps
must be performed two times.
• Your Old School Model Works aircraft should not be
considered a toy, but rather a sophisticated, working model
that functions very much like a full-size airplane. Because of
its performance capabilities, this model, if not assembled and
operated correctly, could possibly cause injury to yourself or
spectators, and damage to property.
• You must assemble this model according to the instructions.
Do not alter or modify this model, as doing so may result in an
unsafe or un-flyable model. In a few cases the instructions may
differ slightly from the photos. In those instances the written
instructions should be considered as correct.
• You must take time to build straight, true and strong.
• You must use a R/C radio system that is in first-class condition,
a correctly sized power system and components (electronics,
batteries, wheels, etc.) throughout the building process.
• You must correctly install all R/C and other components so
that the model operates correctly on the ground and in the air.
(Installation shown in the manual is a suggestion. You may have
to adjust the mounting steps to accommodate the size of your
radio equipment.)
• You must check the operation of the model before every flight
to insure that all equipment is operating and that the model has
remained structurally sound. Be sure to check clevises or other
connectors often and replace them if they show any signs of
wear or fatigue.
• If you are not an experienced pilot or have not flown this type of
model before, we recommend that you get the assistance of
an experienced pilot in your R/C club for your first flights. If
you’re not a member of a club, your local hobby shop has
information about clubs in your area whose membership
includes experienced pilots.
• While this kit has been flight tested to exceed normal use, if
this model will be used for extremely high stress flying, such as
racing, or if a power system larger than one in the recommended
range is used, the modeler is responsible for taking steps to
reinforce the high stress points and/or substituting hardware
more suitable for the increased stress.
Remember: Take your time and follow the
instructions to end up with a well-built
model that is straight and true.
Specifications: Wingspan: 39.5 in. • Wing Area: 470 sq in.
Airframe Length: 32 in. • Weight: 3-3.5 lb.

Page 2 www.oldschoolmodels.com Construction Manual
WARNING
READ THROUGH THIS MANUAL
BEFORE STARTING CONSTRUCTION.
IT CONTAINS IMPORTANT WARNINGS
AND INSTRUCTIONS CONCERNING
THE CONSTRUCTION AND USE OF THIS
MODEL.
A Radio-Controlled aircraft is not a toy!
If misused, it can cause serious bodily harm
and damage to property. Fly only in open
areas, preferably at AMA (Academy of Model
Aeronautics) approved flying sites, following all
instructions included with your radio, powerplant,
electronics and batteries.
We urge you to join the AMA (Academy of Model Aeronautics) and
a local R/C club. The AMA is the governing body of model aviation
and membership is required to fly at AMA clubs.
Though joining the AMA provides many benefits, one of the
primary reasons to join is liability protection.
Additionally, training programs and instructors are available at
AMA club sites to help you get started the right way. There are
over 2,500 AMA chartered clubs across the country. Contact the
AMA at the address or toll-free phone number below:
Academy of Model Aeronautics
5161 East Memorial Drive • Muncie, IN 47302
Phone [phone] • www.modelaircraft.org
IMPORTANT!!! Two of the most important things you
can do to preserve the radio controlled aircraft hobby are to avoid
flying near full-scale aircraft and avoid flying near or over groups
of people.
INCLUDED ITEMS
Wood parts included in this kit:
• 2 - LP1 - Laser Cut 1/8” x 5 x 24 sheet
• 2 - LP2 - Laser Cut 1/8” x 5 x 24 sheet
• 1 - LP3 - Laser Cut 1/8” x 5 x 24 sheet
• 1 - LP4 - Laser Cut 1/16” x 3 x 19 sheet
• 2 - BP1 - Laser Cut 1/8” x 4 x 24 sheet
• 2 - BP2 - Laser Cut 1/8” x 4 x 24 sheet
• 1 - BP3 - Laser Cut 1/8” x 4 x 13 sheet
• 1 - BP4 - Laser Cut 1/4” x 4 x 24 sheet
• 1 - BP5 - Laser Cut 1/4” x 4 x 24 sheet
• 2 - BP6 - Laser Cut 1/16” x 4 x 24 sheet
• 4 - BP7 - Laser Cut 1/16” x 4 x 24 sheet
• 2 - BP8 - Laser Cut 1/16” x 4 x 24 sheet
• 1 - CAP - Laser Cut 1/16” x 4 x 24 sheet
• 5/16” x 5/16” x 36” balsa strips (2 pieces)
• 5/16” x 1/2” x 36” balsa strips (2 pieces)
• 5/16” x 1-1/4” x 36” tapered balsa strips (2 pieces)
• 3/16” x 3/8” x 36” basswood strips (6 pieces)
Hardware parts included in this kit:
• 1 - steerable nose gear gear
• 2 - pre-bent main gear
• 10 - C/A type hinges for control surfaces
• 3 - control horns
• 4 - wheel collars 1/8” I.D.
• 4 - 1/8” plastic landing gear straps
• 6 - 2-56 x 3/4” machine screws
• 25 - 2-56 x 3/4” self tapping screws
• 1 - 10-32 x 1/2” thumb screw
• 1 - 7” canopy
Other items included in this kit:
• Rolled plan
• 1 - Construction Manual
ITEMS NEEDED
Hardware needed (not included in the kit)
For some of these items there is more than one option which will
require a bit of decision making ahead of time. There isn’t a right or
a wrong choice, so choose the items that work best for you.
Our engine size recommendation range is a .25 two-stroke or an
electric motor with similar power output, such as the E-Flite 25.
Remember that the Comet is sport that is intended to fly at average
speeds, not rocket speeds, so prudent throttle management
should be practiced.
Here is a list of additional parts needed to complete and fly this
kit, all of which must be purchased separately. Again, we would
recommended supporting your local hobby shop.
• Powerplant:
if Electric (.25-sized brushless motor, 60amp ESC, 3S LiPo)
if Glow (.19-.30 engine, 4 ounce tank, fuel tubing)
• Propeller
• Engine/Motor mount and mounting hardware
• Receiver - (4 channel minimum)
• Servos with 40-70 in./oz. of torque. 1 for each elevon,
1 for rudder; 1 for throttle (if using a glow engine)
• Pushrods (two 5” for elevons, one 18” for rudder, two 12” (one
for the nose gear and one for throttle if glow powered)
• Clevises for the pushrods (6 if electric, 8 if glow).
• 3 - wheels (2.75” - 3.25” diameter)
• Covering
Additional Required Building Tools and Adhesives
• Drill & assorted drill bits
• Hobby knife and new, sharp blades
• Sandpaper: coarse (80 or 100 grit) & medium (150-200 grit)
• Pencil or pen
• Ruler
• T-Pins
• Waxed paper
• Building board
• Adhesives of your choice. We recommend thin and medium
CA (cyanoacrylate) viscosities
WARNING: This product can expose you to chemicals including lead, which
is known to the State of California to cause cancer and birth defects or other
reproductive harm. For more information go to www.P65Warnings.ca.gov.

Construction Manual www.oldschoolmodels.com Page 3
• 6 and 30 minute epoxy
• Epoxy brushes and mixing sticks
• Threadlocking compound
• Canopy glue
Before Starting Assembly
The Comet should only be built by an experienced builder. If
you’ve never built a kit before it’s quite possible you will have a
great deal of difficulty building this kit successfully.
Closely inspect the supplied laser cut parts for damage. If you find
any damaged or missing parts, contact us immediately.
When removing the laser cut parts from their sheets, you’ll notice
the parts are held in place by several very small “tabs”. These tabs
are uncut pieces of wood and can sometimes make it difficult to
remove a part. Rather than breaking and/or splintering the wood
by forcing out the part, we recommend removing any laser cut
parts from their sheets by using a hobby knife with a new, sharp
blade. A quick cut of the tab will allow the piece to be removed
with no damage. Sand any remainders flush with the part so there
will be no problem aligning them later.
THE COMET USES RIBS THAT HAVE LARGER ALIGNMENT
TABS. IT IS IMPORTANT THAT THESE TABS REMAIN ON
THE PIECES TO AID IN BUILDING A STRAIGHT AND TRUE
MODEL. IF YOU DO BREAK OFF A TAB, IMMEDIATELY
TACK-GLUE IT BACK TO THE PIECE.
It’s best to not remove parts from their sheets until they are needed.
Refer to Appendix A of this manual as a reference to what all the
laser cut parts look like and are called.
For each step, we highly recommend that you dry fit the parts in
each step first. Lightly sand as needed to ensure a good fit. Once
you’re satisfied with the fit, then and only then, glue the parts in
position.
IT IS VERY IMPORTANT THAT YOU ASSEMBLE THIS KIT
IN THE ORDER DESCRIBED. SKIPPING FORWARD IN
THE STEPS COULD LEAVE YOU WITHOUT THE PROPER
LENGTHS OF WOOD TO FINISH THE KIT.
WE’VE INCLUDED ENOUGH WOOD TO EASILY COMPLETE
THIS KIT, BUT YOU MUST TAKE CARE TO PROPERLY
MEASURE AND NOT WASTE WOOD WHEN CUTTING.
All photos shown in this manual were of the prototype Comet.
Several pieces have changed slightly with improvements we’ve
made so they might look a little different in some steps.
Online Supplementary Photos
We realize that the smaller black-and-
white photos in this manual might not
show some of the steps as clearly as
you might want. So we’ve anticipated
this and made these photos available
on our website. You can either scan the
QR code or type this address into your
browser:
www.oldschoolmodels.com/mpics/comet
Let’s begin construction by working on the center section of
the Comet.
Prepare your work area
You’ll need a flat building surface that is a minimum of 40” wide as
the Comet is built as a one-piece airframe.
Cut out the nose section of the plans along the dotted line, then
tape this section in place on the plans to form a 1-piece plan with
the nose section attached.
Position plan over your building surface and tape into position.
Tear off a few lengths of waxed paper to cover plan, then tape
them into position, covering the plan.
Step 1 - Alignment triangle
Pre-cut into LP3 is a triangle, that
can be used to vertically align any of
the parts in the construction of your
Comet. LP3 also includes a foot piece
that can be used with the triangle,
holding the triangle vertical hands-
free.
Step 2 - Center Section (nose gear mount)
Locate both F5 pieces from the LP2
sheets. Glue both of these pieces
together to form a thicker F5. This
will be the mount for the nose gear.
Note that the shape of this piece
has changed from what’s shown
here to include a cutout to allow air
and tubing to pass through.
Step 3 - Center Section (mount nose gear block)
In your Comet kit, there is a separate
hardware bag which contains all the
pieces to assemble the nose gear.
From this bag, locate the nose gear
mounting block, the 4 mounting
screws and the 4 t-nuts from this
package. Use these pieces to
mount the nose gear block to the
assembled F5 as shown here.
You may need to use a cutoff wheel to trim the screws length after
they are installed.
Step 4 - Center Section (R1As)
Locate both R1A and R1B pieces from
the LP1 sheets. Align the curvy cuts
in R1A and R1B to create a finished
R1. Pay attention when joining so you
align the engraved circles next to each
other. Make two finished R1 pieces.
Step 5 - Center Section (attach
nose gear block)
Take one of the completed R1 pieces
and glue the F5 assembly to it. Make
sure it is 90° from the side and the nose
gear block is positioned as shown here.

Page 4 www.oldschoolmodels.com Construction Manual
Step 6 - Center Section (F6)
Locate F6 from LP3 Glue it in position
making sure it is 90° from R1.
Step 7 - Center Section (F6)
Locate F8, F9 and R0 from LP3
Glue F8 in position making
sure it is 90° from R1. Once
the glue has cured, position R0
and F9 in position as shown,
making sure that R0 fits in
the center notch of F9. Once
they are aligned properly, glue
them in position.
Step 8 - Center Section (attach the other R1)
Locatetheremaining
R1 assembly. Glue it
in place as shown,
making sure all of
the tabs from F5, F6,
F8 and F9 fit into the
slots on R1. Make
sure both sides are
straight and parallel.
Step 9 - Center Section (F7)
Locate F7 from LP3. This fits on the
underside of the center section and
the rounded side points towards
the firewall. Once satisfied with the
fit, glue in position.
Step 10 - Center Section (attach R1Ds)
Locate the two R1D
pieces from BP3.
These are glued to
the outside of the
R1s and will act as a
shelf when attaching
the forward sheeting
later on in the build.
Use the lightening
cutouts and the
extended tabs on F6
to properly align these pieces.
Step 11 - Center Section (affix to building surface.)
With the main work on the center section finished, it is time to
attach it in place over the plans. Carefully pin it in position making
sure it’s straight and true. When in position, locate the 2 TEJ pieces
from BP2. These
are jigs used to
properly space the
ribs. These pieces
are symmetrical so
no worries about
placing them in the
wrong direction.
Pin these in place
as shown on the plans, over the trailing edge. Use a long straight
edge to assure that both edges line up. The inner notch will fit
around the extended tab on the back of the R1 pieces.
Step 12 - Wing Assembly (R2s)
Locate both R2A pieces from LP1 and
both R2B pieces from the LP2. Align
the curvy cuts in R2A and R2B to create
a finished R2. Pay attention when
joining so you align the engraved
circles next to each other. Make two
finished R2 pieces.
All of the following steps to build the wing should be
performed to construct both the left and right wing at the
same time.
Step 13 - Wing Assembly (LEJ)
Locate both LEJ pieces from BP2. These are also jig pieces and
will be used to locate the forward tabs on each of the ribs. The
un-notched end will fit up against the center section and will angle
rearwards towards the outer rib. Do not pin in place yet.
Step 14 - Wing Assembly (R2s)
Locate both completed R2
ribs. Carefully place these
in position, one on each
side of the center section.
The rear tab will fit into the
REJ jig and the front tab
will fit into the LEJ jig.
Step 15 - Wing
Assembly (ribs R3-R5)
Locate both R3 ribs from
LP2 and both the R4
and R5 ribs from the BP1
sheets. Carefully place
these in position. The rear
tabs will fit into the REJ jig
and the front tab will fit
into the LEJ jig. Make sure
the tabs are pushed all the
way into the jigs, so they are resting on the plans.
When satisfied of the alignment, pin both LEG jigs into place on
to your building board.

Construction Manual www.oldschoolmodels.com Page 5
Step 16 - Wing Assembly (rear lower spar)
Measure and cut both
rear lower spars from a
single piece of 3/8” x
3/16” basswood.
These pieces run from
the middle of the center
section to the point
where it meets the front
spar as noted on the
plans. Take time to measure correctly before cutting. Starting with
the outside rib (R5), slide each spar in position into the pre-cut
pocket on the bottom of each rib. Be careful that you do not break
off the tabs as they are used to hold these spars in position.
Do not glue in place yet.
Step 17 - Wing Assembly (ribs R6-R8)
Locate both R6 and R7 ribs
from BP1 and both R8 ribs from
BP2. Carefully place these in
position. The rear tabs will fit
into the REJ jig and the front
tab will fit into the LEG jig.
Make sure the tabs are pushed
all the way into the jigs, so they
are resting on the plans.
Now take the time to make
sure all of the ribs are aligned
to the plans and standing straight (90° to the building board). Tack
glue the tabs of each rib to the LEJ and REJ jigs so they’ll stay in
place.
Step 18 - Wing Assembly (trailing edge)
Measure and cut each of the
5/16” x 1/2” balsa strips to
create the trailing edges for
each side of the Comet. Glue
to all the ribs with the 1/2”
side up against the ribs.
Step 19 - Wing Assembly (front lower spar)
Measure and cut both front
lower spars from 3/8” x 3/16”
basswood.
Take time to measure correctly
before cutting. Slide these spars
in position in the same manner
as you did with the rear spars,
making sure not to break off any
of the tabs.
When satisfied with the alignment, glue the front and rear spars in
place, making sure they are attached to all of the ribs and to each
other.
Step 20 - Wing Assembly (cut upper spar)
Now it’s time to measure and cut the upper spars (both front and
rear). Measure and cut one of the 3/16” x 3/8” basswood strips to
use as the upper spar. Apply glue to the top of the ribs where they
will contact the upper spar.
Take time to measure correctly
before cutting and then place
the spars in position, making
sure they are fully seated into
the cutouts of each rib.
When satisfied with the
alignment, glue the front and rear spars in place, making sure they
are attached to all of the ribs and to each other.
Step 21 - Wing Assembly (leading edge)
Locate the 5/16” square balsa
sticks as these are used for
the leading edge. Carefully
measure, cut and sand them
so they fit properly. When
satisfied, glue in position. We
recommend a thicker, gap-
filling C/A glue for this step.
Start at R1 and slowly work
your way to the tip. Also make sure the ribs are straight as you go
work your way across the wing.
Step 22 - Wing Assembly (rear sheer webs)
Locate sheer webs WR1-WR4
from BP6. These are glued in
place on the back edge of the
upper and lower rear spars.
Test fit each of these before
gluing in place, sanding as
necessary for a good fit.
Step 23 - Wing Assembly (front sheer webs)
Locate sheer webs WF1-WF5
from BP6. With the exception of
WF5, these are glued in place
on the back edge of the upper
and lower front spars. WF5 is
glued to the front of the spars.
The left and right edges of these sheer webs might have to be
beveled (angled) slightly to allow them to fit correctly.
Test fit each of these before gluing in place, sanding as necessary
for a good fit.
Step 24 - Wing Assembly (leading edge sheeting)
Locate the 4 SH1s from BP7 and
the 4 SH3’s from BP8. SH1 and
SH3 mate up with each other as
shown here. Glue these together
to make 4 SH1 sheets.
Step 25 - Wing Assembly (leading edge sheeting)
Locate the 4 SH2s from BP8.
These mate up with the SH1
assemblies as shown. Glue
these together to make 4
completed leading edge
sheets.

Page 6 www.oldschoolmodels.com Construction Manual
Step 26 - Wing Assembly (attach sheeting)
Take two of the completed
leading edge sheets from the
previous step as they will be
glued in position on the top of
the wing, as shown here.
We find it best to lay a bead
of glue along the edge of the
sheeting where it butts up
against the leading edge .
Make sure it is also contacting
each of the ribs. As a general rule, don’t use super-fast curing C/A’s
for the step as you will need a bit of time to make sure everything
is in place.
Glue one sheet on the left and the right wings.
Step 27 - Center Section (install F4)
Locate both F4s from the LP2
sheets. These are glued in place
as shown here, adding structural
strength by tying both the upper
and lower front spars to the
center section.
Don’t go overboard, but do use
a good amount of glue to make
sure these pieces are properly
secured to the spars and to the center section sidewalls (R1).
Step 28 - Center Section (top sheeting)
Using a bit of the leftover
1/16” sheeting from the BP6
and BP8 sheets, measure,
cut and glue together the
sheeting to cover the top of
the center section.
When measuring, make sure
that the grain is crosswise
(flowing from R1 to R1).
When edge gluing the
sheeting pieces together, first
make sure the edges are flat
(give a quick, swipe or two
with a sanding block).
Work from the rear of the center section, forward. You’ll need to
cut and join a few pieces together but be sure to stop an inch or
two behind the F5 (nose gear mount). You’ll need this open to aid
in mounting your powerplant.
Step 29 - Wing Assembly (cap strips)
Cut several 1/16th x 1/4” x
36” balsa strips from BP9.
Carefully measure and cut cap
strips to cover the top of each
R2-R8 rib. These strips should
be centered on each rib and
extend from the trailing edge
stock up to the back of the
leading edge sheeting.
Step 30 - Wing Assembly (tab removal)
Once all the glue has cured, remove the Comet assembly from the
building surface and flip it over.
Now it’s time to remove all the tabs from the ribs. All ribs will have
a rear and forward tab, as well as the smaller tabs that held the
lower spars in place. All of them need to be carefully cut away
and the ribs lightly sanded to maintain their airfoil shapes. There’s
a number of ways to do this but we find a Japanese saw is the
perfect tool. These saws are small, have flexible blades and the
lack of off-set teeth makes a smooth, straight cut.
Step 31 - Center Section (servo rails)
You should have several
leftover lengths of the
3/16” x 3/8” basswood
from trimming the spars.
These pieces will be used
to create the servo rails in
the center section. You’ll
need two of them - one
rear, one front, and two
which are back-to-back in
the middle slot.
Glue these in position.
Step 32 - Wing Assembly (R3C)
Locate both R3Cs from
LP2. These are doublers
for the main gear. They
are attached to the inside
edge of each R3. The
groove should line up
with the matching groove
in R3, and the edges of
R3C and R3 should be
flush with each other.
Step 33 - Wing Assembly (R2C)
Locate both R2Cs from LP1.
These are also doublers for the
main gear. They are attached
to the inside edge of each
R2. The long slot should be
aligned in the middle of the
slot in R2. Also, the edges of
R2C and R2 should be flush
with each other.

Construction Manual www.oldschoolmodels.com Page 7
Step 34 - Wing Assembly (G1 & G2)
Locate the G1s and G2s
from LP3. 2 G2s will be
stacked on top of each
other, then a G1 will be
added, as shown here.
The position of the G1 is
critical as the center cut in
it should line up with the
slot in the R2C installed in
the previous step.
We recommend dry-fitting these first, then gluing together. Try to
keep glue out of the slot in G1 as this is where the main landing
gear will be mounted.
Step 35 - Wing Assembly (G4)
Locate the G4s from LP3.
One G4 will be glued
over the slot in R2C. This
will form a pocket where
part of the main gear will
slide into. Be sure to keep
glue out of this pocket.
Step 36 - Wing Assembly (leading edge sheeting)
Using the 2 leftover leading edge sheets you assembled back
on step 29, use the same techniques to attach the leading edge
sheeting on the bottom surface of the wings.
Step 37 - Wing Assembly (elevon rails)
Using more of the leftover lengths of the 3/16” x 3/8” basswood
measure and cut 4 elevon mounts. These will span the distance
from R3 to R4 and fit into the cutouts towards the rear of these ribs,
on the bottom of the wings.
When measuring, cut these mounts to leave an extra 1/16” or so
past the outside edges of the ribs.
Make they are fully seated in the cutouts, then glue in place.
Step 38 - Wing Assembly (TIP install)
Locate both TIP pieces from
BP4. One is glued to the outside
of each R8 rib as shown here.
Step 39 - Wing Assembly (cap strips)
Just as you did back on step 29, cut several 1/16th x 1/4” x 36”
balsa strips from BP9. Carefully measure and cut cap strips to cover
the bottom of each R2-R8 rib. These strips should be centered on
each rib (with the exception of R3 and R4). For those two ribs, the
strips will be glued to the outer edges, using the servo hatch as a
guide. These strips extend from the trailing edge stock up to the
back of the leading edge sheeting.
Also cut smaller strips to frame the front and back edges of the
servo hatch as shown
here. Be careful with
the glue so you don’t
accidentally glue the
hatches to the wing.
The next steps involve assembling and attaching the firewall.
There are two versions - one for glow and one for electric.
For glow power, continue with step 40.
For electric, skip to step 42.
Step 40 - Center Section (glow firewall)
Locate F1 from LP3 and 2
F3s from LP1. These are
glued together to form
the firewall. Note that the
F3s are slightly taller than
they are wide. An easy
way to make sure they’re
aligned properly is to
place F1 on your board so
the engraved “F1” is right-
reading. When attaching the F3s, also make sure the engraved
“F3”s are right-reading.
Both F3’s should be perfectly centered on F1 and we recommend
using epoxy for this step. Clamp the pieces together and allow
them to cure.
Step 41 - Center Section (glow mount)
Locate the engine mount,
mounting screws and
t-nuts you’ll be using for
the Comet (not included).
We recommend that the
engine be mounted so the
crankshaft will be centered
on the firewall. When
properly located, use the
appropriate sized bit and drill
the mounting holes. Lightly tap the blind nuts into place on the
back of the firewall and secure them with a bit of glue.
When finished, skip to step 43.
Step 42 - Center Section (electric firewall)
Locate F1E from LP3 and 2 E3
from LP1. Note that the F3s
are slightly taller than they are
wide. An easy way to make sure
they’re aligned properly is to
place F1 on your board so the
engraved “F1” is right-reading.
When attaching the F3s, also
make sure the engraved “F3”s
are right-reading.

Page 8 www.oldschoolmodels.com Construction Manual
Both F3’s should be perfectly centered on F1 and we recommend
using epoxy for this step. Clamp the pieces together and allow
them to cure.
Step 43 - Center Section (firewall)
Dry fit the firewall into place on the
front of the center section. Lightly sand
as necessary to obtain a good, firm fit.
Now remove the firewall, mix up a bit
of epoxy and glue the firewall to the
center section.
Be sure to form a bit of fillet between
the side walls (R1s) and the firewall to
add additional strength.
This photo shows mounting of the
electric firewall.
Step 44 - Cowl Assembly (frame)
Set the Comet assembly
aside for these next few
steps as we’ll assemble
the cowling.
Locate CB1 and the four
CTs from LP3. Place CB1
on your work surface
then glue each CT into
the side slots on CB1.
Each CT needs to be at a
perfect right angle and seated firmly into the slots.
Step 45 - Cowl Assembly (frame)
Locate CB2 from LP3. Place the CB1 on
your work surface, with the tabs resting
on the work surface (like a little table).
Press CB2 in place making sure it’s held
at a perfect 90° to CB1 (perpendicular).
Glue the 2 pieces together to form the
frame of the cowl.
Step 46 - Cowl Assembly (forming)
This step will require a lot of pieces,
glued in place to the cowling frame
in pairs. These are the C1-C13
pieces located on BP5 and BP4. It is
recommended to only cut a pair of
these pieces out at one time, starting
with C1.
Position both C1’s as shown here
without glue first. They should butt
up against the vertical spine (CB2)
and be centered on the base (CB1).
When you see how they should line
up, remove them, apply glue and
attach them to the cowl framework.
Step 47 - Cowl Assembly (frame)
Now using the same technique as you did in the last step, slowly
work your way up the framework by attaching the C2 pieces, then
the C3 pieces, etc. Make sure that
everything remains straight as you
don’t want to inadvertently put a
bend in the spine (CB2).
Once the C13s are in place, locate
CR from LP3. This will be glued to
the top of the C13’s and the CR’s
precut slots will fit into the tabs
extending from the spine (CB2).
Note that there is an etched ring on
CR that designates the front face of
the cowl. This circle should be visible
when it is glued in place as it’s used as a reference when sanding
the cowl to shape.
Step 48 - Cowl Assembly (mounting)
Once the glue has cured on the cowl, it’s time to shape it. The
center section of the Comet and
the cowl’s plywood frame will be
your guide in sanding. Slip the
cowl onto the front of the Comet
with the tabs sliding into the slots
on the side of the center section.
Make sure that the cowl rests firmly
against the firewall. Lightly sand as
necessary to get a good fit.
Now, to hold the cowl in position, drill into the holes in each cowl
mounting tab using a 1/16” bit. Make the holes about a 1/2” deep.
Using 4 of the supplied 2-56 x 3/4” self tapping screws, attach the
cowl to the Comet.
Step 49 - Cowl Assembly (sanding)
Sanding starts with the rear part of the cowl, the rectangular section.
Use a sanding block with 80 grit paper to sand the oversized sides
of the cowl so they’re flush with the fuselage (left and right). The
top and bottom should be sanded so they’re 1/16” oversized so
they will be flush with sheeting that will be installed later. Tape a
small piece of leftover 1/16th sheet to the top and bottom of the
firewall to give you a visual reference when sanding.
When finished, the rear of the cowl should have 4 flat sections that
line up with the sides of the center section.
Step 50 - Cowl Assembly (sanding)
Now the cowl can be removed from the Comet as it will make
it easier to form the front of the cowl. As you may recall, we
referenced a circle etched into the CR (front face) of the cowl.
Using your sanding block, take a bit of time to work on the shape
of the cowl, sanding down to
the circle.
Step 51 - Cowl Assembly
(sanding)
With the rear and front surfaces
shaped, now finish the cowl
by gently sanding the center
section to blend the round front
into the square rear. When the
rough shape has been reached,
switch to 150 grit paper to sand
the cowl to it’s final shape.

Construction Manual www.oldschoolmodels.com Page 9
Step 52 - Center Section Assembly (F2)
Flip the Comet so the bottom is
facing up, with the firewall facing
you.
Locate both F2s from LP2. These
will be glued together, to form
a thicker F2. Then this assembly
is epoxied in place in the gap
behind the firewall. Make sure it
is fully seated, making it flush.
Step 53 - Center Section Assembly (U2)
Locate U2 from LP4. Glue in
place as shown, making sure it
is flush with the firewall and both
sides of the center section.
Step 54 - Center Section Assembly (U1 & U3)
Locate U1 and U3 from LP4. U3 will be the battery/fuel hatch and
has a pre-cut circle that designates the rear of the hatch.
U1 is glued to the front of U3 so it forms a lip that will catch under
U2. An easy way to see where it should mount is to slip U1 into the
battery/fuel compartment, under the U2 piece you just installed.
Using a pencil, trace a line on to U1 where it overlaps U2. Now use
this as your guide when gluing it to U3.
Also make sure that U1 is centered left/right on U3.
Step 55 - Center Section Assembly (U3)
Position the finished U3 battery/fuel hatch in place as shown.
Using a pencil, transfer where
the circle on the rear of the
hatch lines up with F7 (already
installed).
Remove the hatch, then drill
and tap F7 for a 10-32 thread.
This is where the included 10-
32 x 1/2 nylon thumb screw
is used to hold the hatch in
place.
Step 56 - Center Section Assembly (U4)
Locate U4 from
LP4. U4 is the radio
hatch and is held in
place with 4 of the
supplied 2-56 x 3/4”
self tapping screws.
Position U4 on the
center section as
shown, then using a
1/16” bit, drill the 4
mounting holes, using the pre-cut holes in U4 as a guide.
Step 57 - Center Section Assembly (rear sheeting)
Hopefully you have been careful with your cutting and have
saved the scrap pieces of 1/16h sheeting from BP6 and the BP8
sheets. Using the leftover
1/16th sheeting, sheet the
remaining portion of the
bottom center section,
similar to the way you
sheeted the top back in
step 28.
Note that if you are using
an electric powerplant, you
need to make a couple of
cutouts in this bottom sheeting to allow the exhaust air to escape.
Step 58 - Center Section Assembly (cowl)
Cut the two, thin internal braces from inside the cowl. They’re not
needed anymore as the cowl is now a rigid structure. Also, they will
interfere with installing the powerplant.
Step 59 - Center Section Assembly (powerplant install)
Measure your cowl from the back of base (part that mounts against
the firewall, not the tabs) to the front edge. It should measure close
to 3-5/8” in length. Add an extra 1/8” for clearance and that gives
a measurement of 3-3/4”. This is the recommended distance from
the firewall to the front of your powerplant’s drive washer (back of
the spinner).
To help aid in the mounting of your powerplant, we’ve included
two parts cut into LP3 - SP1 and SP2. Locate these parts and glue
SP1 to SP2, carefully lining it up. The hole in SP1 is meant to fit
over the prop shaft of your powerplant (you may have to enlarge
is slightly depending on your setup). The SP2 ring acts as a spacer
between the cowl and the back of your spinner. When using this SP
assembly, make sure that the SP2 ring always faces the cowl.
It is strongly recommended that glow engines be side
mounted, with the cylinder is on the starboard side of the
fuselage. Photos shown were of the prototype and we had
a very hard time getting the fuel to flow properly when the
engine was mounted upright.
The next steps involve attaching the powerplant. The steps
you follow depend on your choice of glow or electric.
For glow power, continue with step 60.
For electric, skip to step 61.
Step 60 - Center Section Assembly (glow install)
If you’ve removed the engine mount from the firewall, now is the
time to re-install it.
Using our recommended 3-3/4” distance, drill and tap your mount
for your engine. Now, comes a bit of fun, trial, and hopefully
no error. You’ll need to make the cut out so the engine can be
mounted. There is no quick way to do this, but it all starts with
mounting the cowl, then slowly cutting away the cowl as needed
until there’s just enough cut away to clear the engine so it can be
mounted. Also make sure the muffler
won’t touch and you have access to all
of the mounting screws. Lastly, make
sure that cowl doesn’t interfere the
motion of the throttle arm.
When finished, it should look something
like we’ve shown here.
Skip to step 65.

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Step 61 - Center Section Assembly (electric power - E3)
Locate E3 from LP3.
Position your motor’s
mounting plate so
it’s centered on E3.
Typically, these plates
are in an “X” pattern, so
line it up as shown, then
drill the four mounting
holes and attach the
t-nuts to the back of E3.
Step 62 - Center Section Assembly (electric power - box)
Locate both E1s and both E2s
from LP1. These 4 pieces, along
with EP3 make the electric
motor box as shown here.
There are small relief cutouts in
the tops of E1 and E2 to allow
the blind nuts on the back of
E3 to clear. Depending on your
hardware, you may have to
adjust these gaps to fit.
When satisfied with the fit,
use epoxy to glue the pieces
together making the finished
motor box.
Step 63 - Center Section Assembly (electric power - box)
When the glue has cured, lightly sand the sides of the box smooth
to make sure it will snugly slide into the square cutout on the
electric firewall. (This firewall was installed on the center section
back on step 43.)
Do not sand too much as this should be snug fit, not a loose fit.
Step 64 - Center Section Assembly (electric power - box)
Attach the mounting plate to the motor, then the motor to the
box. it is now time to attach the box to the firewall. 30 minute
epoxy is recommended for this step, but please dry-fit everything
in position first before using glue.
A. - Slide the motor/box assembly into the cowl so the prop shaft
protrudes out the front.
B. - Attach the SP assembly to the prop shaft, making sure it is up
against the drive washer and the SP2 ring is facing the cowl.
C. - Now push this assembly on to the center section, with the
motor box sliding into the firewall until the 4 mounting tabs of the
cowl are properly located. Attach the cowl to the center section.
D. - Make sure the SP assembly is perfectly centered around the
front face of the cowl.
E. - With everything in position, you should be able to tack-glue
the motor box to the firewall in a few spots.
F. - Wait until the glue cures, then remove the SP assembly and the
cowl. You should now be left with a perfectly placed motor box
that can now be permanently glued into position using epoxy.
Step 65 - Center Section Assembly (wire/tubing)
With the powerplant in place, now you can take the time to
complete the engine installation.
• For electric, run the motor’s wires through a couple of the air
cooling openings in the motor box all the way through into the
battery compartment.
• For glow, drill holes as necessary to run the fuel lines and throttle
pushrod through the firewall.
Step 66 - Center Section Assembly (top sheeting)
Now you can finally measure, cut and glue on the remaining 1/16th
sheeting on top of the fuselage, next to the firewall.
Step 67 - Servo installation (steering and rudder)
Locate 1 or 2 of your servos and mount
them to the previously installed rails in
the center section of the airframe. One
will be used if electric for the rudder
and nose steering. Two will be used if
glow as you’ll need the second one for
the throttle.
Every radio setup will be different. In
the electric prototype shown here, we
mounted the rudder servo in center of
the rails.
Step 68 - Servo installation (elevons)
From leftover 3/16” x 3/8” x 36” basswood strip, cut eight 3/4”
pieces. Make a mounting post by laminating two pieces, gluing
the 3/8” sides together to make a 3/8 x 3/8” square post. Make
3 similar posts from the remaining pieces, sanding the ends flat.
Position the aileron servo on the bottom of the aileron servo cover
so the servo arm output shaft is centered in the opening.
On the bottom of each aileron hatch, glue one post on each side
of the servo as shown in the photo.
Note that the left hatch
is a mirror image of the
right hatch.
Now fit the servo
hatches into position
on the bottom of the
wing. Using the pre-cut
holes as a guide, drill four 1/16” mounting holes into the 3/16” x
3/8”basswood mounting strips installed earlier. Harden the wood
with a bit of thin CA and you can use the attach the supplied 2-56
x 3/4” self tapping screws to secure them in place.
Step 69 - Vertical Fin (assembly)
Locate VF1, VF2, VF3
and VF4 from BP4.
These 1/4” thick parts
will make up the vertical
fin. Lightly sand the
edges to make sure they
all mate up properly,
then glue together to
make the complete vertical fin as shown here.
The piece shown separated from the fin is the rudder (VF5). We
have flown the Comet with and without rudder and you can choose

Construction Manual www.oldschoolmodels.com Page 11
to do the same. If you do not want to use the rudder, then glue VF5
to the vertical fin. After flying the Comet, you can always change
your mind by slitting along the join line, shaping and hinging the
rudder, and running a rudder pushrod.
Step 70 - Vertical Fin (attachment)
Permanently attach the vertical
fin to the Comet airframe. Make
sure it’s the proper way up,
it’s exactly centered along it’s
entire length and a perfect 90°
to the wings.
Step 71 - Nose Gear assembly.
Attach the nose gear. The nose gear
wire is pushed up through the block that
was mounted way back in step 3. Slip
the steering arm in place, then push the
nose gear wire all the way through the
block and the arm. Stop when the wire is
flush with the top of the mounting block.
Position the steering arm at a 25-30°
angle, then tighten the set-screw in
the steering arm just tight enough so it
should make a mark on the nose gear
wire. Loosen the screw and remove the
wire. Grind a small flat on the nose gear
where the screw made a mark, then re-attach.
Step 72 - Main Gear assembly.
The main gear slips into the
mounting blocks installed
back in step 34-35. Locate
the 1/8” plastic landing gear
straps and 8 of the 2-56 x 3/4”
self tapping screws. Place
each strap across the wire,
roughly a 1/4” in from the bends. Using a 1/16th bit, drill the two
holes using the straps as your guide. Fasten in place using the
screws. Repeat this for the other side.
Step 73 - Covering
Now it is time to cover the Comet. Remove the powerplant, cowl
gear, pushrods, and any other components that would get in the
way of applying the covering.
Double check that all surfaces are smooth and ready to cover. Sand
as necessary, then cover the entire airframe with the covering/finish
of your choice.
Note that if you’re powering with
an electric motor, we strongly
suggest you make a “cheater
hole” in the bottom of the cowl,
similar to this, so cooling air can
enter the fuselage.
When the covering is complete, re-attach all the components you
removed earlier in this step.
Logos, numbers, etc.
If you want to use graphics similar to the
ones we used, Old School Model Works
has teamed up with Callie Graphics as a
supplier for pre-cut vinyl. They are a very
well known provider of custom graphics
for R/C models.
We have supplied them with the artwork needed to cut the correct
size logos. You can order straight from them, choosing the colors
that work for you.
Contact Callie Graphics at this link: https://callie-graphics.com or scan
the QR code on the previous page.
Note that Callie Graphics is not affiliated with Old School Model
Works, nor does Old School Model Works generate any income
from this partnership.
Step 74 - Cut and hinge the elevons
Locate the two 5/16” x 1-1/4” x 36” tapered balsa strips. Measure
and cut them to the correct length to make the elevons. When
finished, make the necessary slots/holes needed to hinge the
elevons to each side of the wing. We recommend 3 hinges per
elevon and glue them in using thin C/A.
Step 75 - Hinge the rudder
If using the rudder, locate VF5 and shape the leading edge.
When finished, make the necessary slots/holes needed to hinge
the rudder to vertical fin. We recommend 3 hinges spaced evenly
along this joint, again, attached using thin C/A.
Step 76 - Radio and Pushrod Installation
Now it’s time to fit all of the pushrods, control horns and connect
everything so the radio will control the Comet properly. Make sure
that when installing the control horns, they are placed in-line with
the pushrods, and that the line of holes where the clevises attach
are positioned over the hinge line.
For the average pilot, we recommend that clevises are attached to
the outermost hole on each control horn.
Finish the installation of your radio gear by adding the receiver,
flight pack battery and the switch. We mounted the receiver to
the fuselage side using a bit of self-adhesive hook-and-loop (not
included).
For electric power,
locate TF from LP3. This
can be glued in place
and used as the “floor“
to mount the flight
battery to using a bit
of hook-and-loop (not
included).
This tray can slide a bit
fore and aft, so position
it where you want then lock in place with a bit of glue.
Using TF with glow power typically doesn’t work, but it will depend

Page 12 www.oldschoolmodels.com Construction Manual
on your tank. We’ve found that it takes away just enough space to
keep the tank from being able to properly fit.
Step 77 - Attach wheels. Use the included 1/8” i.d. wheel
collars to hold each wheel (not included) on the axles (one on each
side of the wheel). For a maintenance free installation, file a small
flat on the axle where the set screw of the wheel collar touches.
Also use a touch of thread-locking compound to keep the screw
from loosening over time.
Step 78 - Canopy. Finishing the assembly of the Comet is the
canopy. Trim the edges as needed so it is flush with sides of the
fuselage. Also, very lightly sand the bottom surface of the canopy
where it will contact the covering to allow the glue to grip better.
When satisfied with the fit, wash the canopy with warm, soapy
water. When dry attach the canopy to the fuselage with canopy
glue. Use some long strips of low-tack tape to hold the canopy to
the center section while the glue is curing.
This completes the assembly of the Comet. Now you’ll need
to adjust the control throws and check for balance.
Step 79 Recommended C.G. setting:
An important part of preparing the aircraft for flight is properly
balancing the model. This is especially important because of the
various motor/battery combinations that can be used.
CAUTION! DO NOT SKIP THIS STEP!
The recommended Center of Gravity (CG) location for the Comet is
measured back 9.625” from the firewall, and you’ll see this marked
on the plan with this symbol.
If necessary, move the battery, receiver,
and/or add weight to either the nose
or the tail until the correct balance is
achieved. Stick-on weights are available
at your local hobby store and work well
for this purpose.
Recommended Control Throws:
The amount of control throw should be adjusted as closely as
possible using mechanical means, rather than making large
changes electronically at the radio.
By moving the position of the clevis at the control horn toward
the outermost hole, you will decrease the amount of control throw
of the control surface. Moving it toward the control surface will
increase the amount of throw. Moving the pushrod wire at the
servo arm will have the opposite effect: Moving it closer to center
will decrease throw, and away from center will increase throw.
Work with a combination of the two to achieve the closest or exact
control throws listed.
Elevons 1/2” up/down
Rudder 3/4” left/right
(Expert tip: Once the control throws have been set, cut a few pieces of
medium silicone fuel tubing (or heat shrink tubing) to go around each
of the clevises. This will keep them from opening during flight.)
Preflight:
Charge both the transmitter and receiver pack for your airplane.
Use the recommended charger supplied with your particular radio
system, following the instructions provided with the radio. In most
cases, the radio should be charged the night before going out
flying.
Check the radio installation and make sure all the control
surfaces are moving correctly (i.e. the correct direction and with
the recommended throws). Test run the engine and make sure it
transitions smoothly from idle to full throttle and back. Also ensure
the engine is tuned according to the manufacturer’s instructions,
and it will run consistently and constantly at full throttle when
adjusted.
Check all the control horns, servo horns and clevises to make
sure they are secure and in good condition. Replace any items
that would be considered questionable. Failure of any of these
components in flight would mean the loss of your aircraft.
Range check your radio before flying
Before each flying session, range check your radio. This is
accomplished by turning on your transmitter with the antenna
collapsed. Turn on the radio in your airplane, but do not attach the
arming switch.
With your airplane on the ground, you should be able to walk 30
paces away from your airplane and still have complete control of
all functions.
If not, don’t attempt to fly! Have your radio equipment checked
out by the manufacturer.
AMA Safety Code.
Old School Model Works highly recommends that before flying
this, or any other model aircraft, please read through and adhere
to the guidelines spelled out the Academy of Model Aeronautics
Safety Code.
A copy of this can be downloaded from their website:
https://www.modelaircraft.org/sites/default/files/105.pdf
Warranty Information
Old School Model Works guarantees this kit to be free from
defects in both material and workmanship at the date of purchase.
This warranty does not cover any parts damage by use or
modification. In no case shall Old School Model Works’ liability
exceed the original cost of the purchased kit. Further, Old School
Model Works reserves the right to change or modify this warranty
without notice.
In that Old School Model Works has no control over the final
assembly or material used for the final assembly, no liability shall be
assumed nor accepted for any damage of the final user-assembled
product. By the act of using the product, the user accepts all
resulting liability.
Limit of Liability
In the use of this product, our only obligation shall be to replace
such quantity of the product proven to be defective. The user shall
determine the suitability of the product for his or her intended use
and shall assume all risk and liability in connection therewith.
If the buyer is not prepared to accept the liability associated with
the use of this product, the buyer is advised to return this kit
immediately in new and un-opened condition.

Construction Manual www.oldschoolmodels.com Page 13
APPENDIX A

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