Stevens Aero Model Scimon 20 Manual

Beginner Friendly - Elastic Launch Glider
This kit builds three gliders.
Wing Span: 7.9 inches | Wing Area: 13.5 square inches | Average Flying Weight: 3 grams
Build Instructions - Version 1.08a (revised 12.14.2015)
Build Instructions
scimon 20 Build Instructions. © 2014 Stevens AeroModel all rights reserved.!Page 1

WARRANTY
Stevens AeroModel guarantees this kit to be free from defects in both material and workmanship at the
date of purchase. This warranty does not cover any component parts damaged by use or modification.
In no case shall Stevens AeroModel’s liability exceed the original cost of the purchased kit. Further,
Stevens AeroModel reserves the right to change or modify this warranty without notice.
LIABILITY RELEASE
In that Stevens AeroModel has no control over the final assembly or material used for final assembly,
no liability shall be assumed nor accepted for any damage resulting from use by the user. By the act of
using the user-assembled product, the user accepts all resulting liability.
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 unused condition to the place of purchase.
THIS PRODUCT IS NOT INTENDED FOR CHILDREN 12 YEARS OF AGE OR YOUNGER.
WARNING: This product may contain chemicals known to the State of California to cause cancer and
or birth defects or other reproductive harm.
PRODUCT SUPPORT
This product has been engineered to function properly and perform as advertised, with the suggested
power system and supporting electronics as outlined within this product manual. Product support
cannot be provided, nor can Stevens AeroModel assist in determining the suitability or use of
electronics, hardware, or power systems not explicitly recommended by Stevens AeroModel.
For product assembly support, replacement parts, hardware, and electronics to complete this model,
please contact Stevens AeroModel at www.stevensaero.com.
Stevens AeroModel
26405 Judge Orr Rd. Colorado Springs, CO 80808 USA
719-387-4187 www.stevensaero.com
Build Instructions
scimon 20 Build Instructions. © 2014 Stevens AeroModel all rights reserved.!Page 2

scimon 20 - Kit Inventory
Kit Contents
☐Illustrated build instruction manual
☐Plan set, 1 sheet, 11 in. x 17 in.
☐Laser-cut wood, 3 sheets, makes 3 gliders
☐Balsa fuselage, pre-cut, 3 each
Hardware bag
☐1 Aluminum alignment pin, 1/4 in. x 1/16 in.
☐1 Hardwood dowel, 4 3/4 in. x 1/4 in.
☐1 Contest grade, elastic rubber strip, 24 in. x 1/8 in.
☐Modeling clay, ballast, 6 grams
Introduction
The scimon 20 Catapult Launch Glider was inspired by the elegant “Simple Simon” glider designed by K.
Krempetz. Using modern design and construction techniques developed by Stevens AeroModel, and
design input from champion free-flight experts, Mark Covington and Don DeLoach, this kit is an excellent
introduction to the basic principals of model construction and flight.
The scimon 20 Catapult Launch Glider was originally designed as a legal contestant in its class, at all
Science Olympiad events (using contest rules established 2013 – rules are revised each year it it your
responsibility to ensure your glider meets the current rule set). If built according to the instructions it will
fly very well and meet all of it’s design parameters. The scimon 20 was designed to teach the basic
principals of flight. The basics of airplane design and model construction, as well as the effect of control
surfaces on the flight envelope of an airframe. Not only is this kit instructional, it is also very satisfying to
build, and a lot of fun to fly.
Note: The scimon 20 is designed for both right-handed (RH) and left-handed (LH) pilots. As such there
are a few differences in construction that will be called out in the build sequence.
Build Instructions
scimon 20 Build Instructions. © 2014 Stevens AeroModel all rights reserved.!Page 3

Required Tools and Supplies
Flat work surface - Table top or building board, make sure the building surface is warp free
Glue - Medium Cyanoacrylate CA (super glue)* or Aliphatic Resin (wood glue)*
*Cyanoacrylate Glue (CA) also known as super glue, is a quick setting glue that bonds in seconds.
Please use caution with this type of glue. If this is the first time using CA, we recommended that you keep
finger tips away from glue joints while assembling the model, CA can bond skin instantly. The use of a
precision glue tip provides the most control of glue application. When using CA to assemble this model
tack glue assemblies first, after the parts are joined revisit all joints with a second application of glue. CA
glue and glue tips are available from stevensaero.com. Follow all manufacturers instructions for use.
*Aliphatic Resin also known as wood glue under the brand names, Titebond or Elmer’s etc., are also a
good choice. This type of glue takes much longer to cure. We recommend pining the parts together after
assembly, allow ample time for the glue to setup. Aliphatic resin is not an instant glue so be prepared to
take some time with the assembly of the model. Follow all manufacturers instructions for use.
Optional Tools and Supplies
Our scimon model, as delivered, can be assembled entirely without the aid of hobby knifes, pins, or
abrasives, making it ideal for use in instructional environments. As such the following items are, in-fact,
optional and suited for progressing builders, craftsman, and serious competitors.
Hobby knife - X-actoRor Excel style hobby knife with supply of #11 blades
Sanding block - Loaded with 250 - 400 grit sand paper (sanding blocks are available at
stevensaero.com)
Straight pins - Secure parts to building board and each other while glue dries
Masking tape - Low-tack blue painters’ tape
Building board - Soft flat work surface that will accept straight pins (balsa building boards are available
at your local hobby shop, or make one using a piece of drop ceiling tile).
Drill bit, 1/16 in. - Use as an alignment fixture, if aluminum alignment pin is lost
Hobby clamp or clothes pins - Used to hold parts together while glue dries
Clear lacquer - Protects the finished model from moisture without adding significantly to the models final
flying weight. Use only one light coat. We recommend DEFT brand clear-lacquer in a spray can,
available at most hardware or home improvement stores.
Design Master Color Tool - If desired add a little color to the model. Use color sparingly, i.e., on a wing
tip or the tail planes. Paint adds weight and can effect the performance of the finished model, available at
most arts and crafts stores.
Build Instructions
scimon 20 Build Instructions. © 2014 Stevens AeroModel all rights reserved.!Page 4

General Assembly Instructions
Thank you for purchasing The scimon 20 Catapult Launch Glider from Stevens AeroModel. This model
has been developed and manufactured using state-of-the-art CAD/CAM systems. Our kits feature a
unique interlocking construction process, that when compared to traditional building methods, saves
countless hours of measuring, cutting, sanding, and fitting. Also included in this kit are building fixtures
which will aid in assembly, their construction and use will be described in the step by step build
instructions. We are certain that you’ll find our kits to offer a truly exceptional build experience.
As this kit is recommended for the novice model builder and pilot, we invite beginners who have
purchased this kit to seek the help of an experienced builder and pilot. If at any time during the assembly
of this kit, should you run across a term or technique that is foreign to you, please do not hesitate to
contact our staff with your questions.
IMPORTANT!
Please READ and REREAD these build instructions along with any other included documentation before
starting your build and/or contacting our staff for builder support.
Pre-Sanding (Optional)
Before removing any parts from the laser-cut sheet wood, use a sanding block loaded with 250 - 400 grit
sandpaper and lightly sand the back side of each wood sheet. This step removes any residue produced
as a result of the laser cutting process. This step also slightly reduces the thickness of each sheet of
wood. We have found that most stock wood sizes run several thousandths of an inch oversized. Leave
all parts in the sheet wood until required for assembly.
Protecting Your Work Surface
Use the poly tube that this kit was packed in to protect your work surface from the glues used during
assembly of the model.
Bonding the Assembly
This product’s tabs and notches interlock like a 3D puzzle. We strongly suggest that when fitting parts,
you dry fit (use no glue) the parts together first. It is advised to work 1 - 2 steps ahead in the instructions,
using this dry-fit technique. This allows the opportunity to inspect the fit and location of assembled
components, and shows the benefits of our construction technique. Once you arrive at the end of a major
assembly sequence, square your work on a flat work surface or by using the included assembly fixtures
and bond the dry fit joints with glue. Using the dry-fit process, you’ll be able to recover from a minor build
mistake and will ultimately end up with a square and true assembly.
When using CA, apply glue with a fine-tip CA glue applicator. Unless otherwise noted in the instructions,
we find it easier to “tack glue” parts (temporarily bonding parts in assemblies, using a small dot of glue).
When using wood glue, apply a small amount of glue to the surfaces to be bonded. After assembly, pin
your parts into place and allow them to dry throughly.
Sanding
Do not sand the individual parts of this model. This kit is precision cut to assemble with the correct angles
and incidences to ensure proper flight performance. If desired the laser burn may be removed after
assembly.
Never Force the Fit!
This is a precision laser-cut kit. Our lasers cut to within 5 thousandths of an inch in accuracy. Yet the
wood stock supplied to us by the mill may vary in thickness by up to 20 thousandths. This variance in the
wood stock may cause some tabs and notches to fit very tightly. With this in mind, consider lightly
sanding or lightly pinching a tight-fitting tab, rather than forcing the parts together. You will break fewer
parts in assembly, and end up with a square and true airframe.
Build Instructions
scimon 20 Build Instructions. © 2014 Stevens AeroModel all rights reserved.!Page 5

Assembly
Building Fixture 1 parts are designated with the letter “J” followed by a number. Parts have been
numbered sequentially. The building fixture build order includes parts J1 and J2.
1. Locate parts J1 and J2 (sheet 01/02, 1/20 in. balsa). Insert the tab in J2 into the slot in J1.
Ensure that they are perpendicular (form a 90 degree right angle) to each other. Please
refer to the Building Fixture 1 detail drawing on the plan set.
If using CA, bond parts together. If using wood glue, lightly coat the surfaces to be bonded
then assemble, allow ample time for the glue to dry. It may help to pin these parts into place
to keep them aligned while the glue dries.
Wing Assembly. Wing parts are designated with the letter “W” followed by a number. Parts have been
numbered sequentially. The wing build order includes parts W1, W2, and W3.
2. Locate the wing parts (sheet 01/02, 1/20 in. balsa). Remove the parts marked with a W.
Lay them on your work surface with the etch marks facing up. If desired you may pin or
tape W1 to the work surface. Note: The curved section of the wing is the leading edge, the
straight section is the trailing edge.
3. Locate wing part numbered W2 (sheet 01/02, 1/20 in. balsa) right wing tip. Use the
interlocking tabs and notches to place the wing tip. Ensure that the leading and trailing
edges are correct and the wing panels are fully seated. With the base of Building Fixture 1
on the work surface, aligned with the trailing edge of the wing, prop up wing panel W2 to the
correct dihedral angle. Using the fixture also provides the correct amount of wing washout.
If using CA, bond parts together. If using wood glue, lightly coat the surfaces to be bonded
then assemble, allow ample time for the glue to dry. It may help to pin these parts into
place to keep them aligned while the glue dries.
4. Repeat “□□” Step 3 for the left wing panel, part W3 (sheet 01/02, 1/20 in. balsa).
Wing/Fuselage Assembly. Fuselage parts are designated with the letter “F” followed by a number. Parts
have been numbered sequentially. The fuselage build order includes parts F1, F2, and F3. The front/
nose of the model is designed to meet current Science Olympiad (2013) rules and should not be
modified. Doing so will disqualify the model from use in competition.
5. Locate part F1 (fuselage, 3/32 in. balsa). Identify the front of the fuselage marked F1. Just
behind the cutout for ballast, at the top of the fuselage are two tabs that will secure the
wing. Trial fit the completed wing assembly to the fuselage. Remember: The leading edge
of the wing is curved and this must face the front of the fuselage. Place the base of Building
Fixture 1 on the underside of the wing in the corner created between the wing and the
fuselage joint. It may help to invert the assembly. Ensure that the wing is perpendicular
(forms a 90 degree right angle) to the fuselage. Refer to the Wing to Fuselage Sub
Assembly detail drawing on the plan set.
If using CA, bond parts together. If using wood glue, lightly coat the surface(s) to be
bonded then assemble, allow ample time for the glue to dry. It may help to pin these parts
into place to keep them aligned while the glue dries.
Build Instructions
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Build Instructions
scimon 20 Build Instructions. © 2014 Stevens AeroModel all rights reserved.!Page 7
F6
Step 1
Step 2
Step 2 Cont.
Step 3
Step 5 Cont.
Step 5
J1
J2
W1
W2
Bottom View
W1
W3
W2
Leading Edge
Trailing Edge
Building Fixture 1
Building Fixture 1
Right
W1
W3
Building Fixture 1
Left
F1
Building Fixture 1
Front
Trailing
Edge
Leading
Edge
Top View

Assembly (continued)
6. Remove one each, part F2 and F3 (sheet 02/02, 1/32 in. ply). Locate the 1/4 in. x 1/16 in.
aluminum alignment pin packed in the hardware bag. Use the aluminum tube as an
alignment fixture to place F2 and F3 on the right and left sides of the fuselage. Insert and
center the aluminum tube in the alignment hole at the front of the fuselage, do not glue the
tube into the fuselage. Next slide F2 over the tube on the right side of the fuselage. Make
sure that the rear of F2 is fully seated against the underside of the wing. See Assembly
Profile View (right) detail drawing for proper placement. Do not glue the alignment pin as
this will be removed after assembly.
If using CA, bond parts together. If using wood glue, lightly coat the surface to be bonded
then assemble, allow ample time for the glue to dry. Clamp F2 in place to keep it aligned
while the glue dries, use a hobby clamp or ordinary clothespins.
7. Slide F3 over the alignment pin on the left side of the fuselage. Make sure that the rear of
F3 is fully seated against the underside of the wing. Note: Part F3 has no opening and will
form the bottom of the ballast compartment. Do not glue the alignment pin as this will be
removed after assembly.
If using CA, bond parts together. If using wood, glue lightly coat the surface to be bonded
then assemble, allow ample time for the glue to dry. Clamp F3 in place, use a hobby clamp
or ordinary clothespins.
8. Remove the alignment pin (aluminum tube) from the fuselage, before the glue dries.
Tail Surfaces. Tail surface parts are designated with letters “H” and “V”. Also required to assemble the
tail surfaces is building fixture 2, J3.
Note: The scimon glider was designed with the option to be built for both right-handed and
left-handed pilots. Please follow the build sequence, differences in construction will be
called out in the individual assembly steps below.
9. Remove the horizontal stabilizer part H (sheet 01/02, 1/20 in. balsa) and fit it to the rear of
the fuselage. Do not glue it in place! Make sure that the etched side faces up. Next,
remove horizontal stabilizer alignment fixture, Building Fixture 2, part J3-RH/LH (sheet
01/02, 1/20 in. balsa) slide it over the top of the rear fuselage. Refer to Horizontal Stabilizer
- Back View detail drawing on the plan set for proper placement.
IMPORTANT!
For right-handed launch use part J3-RH, (half-round shaped fixture) ensure that the
etching on part J3-RH faces the rear of the fuselage.
For Left-handed launch use part J3-LH, (triangular shaped fixture) ensure that the etching
faces the rear of the fuselage.
The angle at which the assembly fixture sets the horizontal stabilizer controls the diameter
of the circular flight path of the model.
Build Instructions
scimon 20 Build Instructions. © 2014 Stevens AeroModel all rights reserved.!Page 8
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Build Instructions
scimon 20 Build Instructions. © 2014 Stevens AeroModel all rights reserved.!Page 9
F1 H
Step 9
Top View
Step 9 Cont.
RightLeft
Right-Handed Launch
J3-RH Sets Stab Tilt
Step 9 Cont.
RightRight-Handed Launch
J3-RH
H
Building
Fixture 2
Steps 6 thru 8
Steps 6 thru 8 Cont. Bottom View
F1
F3
F2
Align parts
through holes
F2
F3
F1
Seat against
wing
Step 13
Step 14
Step 14 Cont.

Assembly (continued)
10. When satisfied with the placement of the horizontal stabilizer bond it to the fuselage. Do
not glue the alignment fixture to the model.
If using CA, bond parts together. If using wood glue, lightly coat the surfaces to be bonded
then assemble, allow ample time for the glue to dry. It may help to pin this part into place to
keep it aligned while the glue dries.
11. The final step in model assembly is to fit the vertical stabilizer to the fuselage, part V (sheet
01/02, 1/20 in. balsa). Insert the tab on the lower part of the vertical stabilizer into the slot
on the horizontal stabilizer. Refer to Assembly Top View detail drawing on the plan set for
proper placement.
IMPORTANT:
For right-handed launch use the slot marked RH on the horizontal stabilizer.
For Left-handed launch use the slot marked LH on the horizontal stabilizer.
The angle set by the slots in the horizontal stabilizer of the vertical stabilizer controls the
transition of the model from the launch portion of flight to the glide portion of flight.
12. When satisfied that the vertical stabilizer is in the proper slot and that it is perpendicular
(forms a 90 degree right angle) to the wing center section, not the horizontal stabilizer, bond
it in place.
If using CA, bond parts together. If using wood glue, lightly coat the surfaces to be bonded
then assemble, allow ample time for the glue to dry. It may help to pin this part into place to
keep it aligned while the glue dries.
Catapult Assembly. Locate the hardwood dowel and the 24 in. x 1/8 in. rubber strip. These components
are assembled to create the catapult launcher. Please see the Catapult Assembly detail drawing on the
plan set.
13. Loop the elastic rubber strip in half, tie an overhand knot in the end within two inches,
where the loose ends meet. Pull the knot snug, working the knot within one-half inch of the
ends.
14. Place the dowel on top of the rubber loop within two inches of the knot. Wrap the loop end
of the elastic around the dowel and feed through the opening between the dowel and the
knotted end of the rubber strip and pull snug. Ensure that the knot is located against the
dowel.
Optional: If desired, sand the model to remove the laser burn from the model. You may also paint the
model with clear-lacquer to protect it from moisture, or spray a little color on the model to make it uniquely
yours.
Please continue to the Setup and First Flight instructions to prepare the competed model for flight.
Build Instructions
scimon 20 Build Instructions. © 2014 Stevens AeroModel all rights reserved.!Page 10
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Build Instructions
scimon 20 Build Instructions. © 2014 Stevens AeroModel all rights reserved.!Page 11
Step 12 V
90 Deg.
W
Balance
Balance Points
Horizon
In this example, the
model is “Nose Down”.
Remove a small amount
of ballast from nose or
add weight to tail.
Complete
Ready to Fly!
Step 12 Cont.
RightLeft
V
Right-Handed Launch
W
Step 11
Left
Right
F1 H
V
Right-Handed Launch
RH
Launch
wing near
perpendicular
Right-Handed Launch
Launch
60-70 degrees
Right-Handed Launch

Setup
Balance the model. Balance the model as per the guidance given on the plan set. The starting balance
point (Center of Gravity or CG) has been marked on the wing of the glider in the form of two small holes.
See the plan set for the location of the balance point.
Suspend the model from your thumb and index finger at the balance points on right and left of wing.
When viewed from the side the bottom of the fuselage should appear to hang level with the horizon. If
the model hangs nose down, remove clay ballast from the nose or add clay ballast to the tail. If the model
hangs tail low with the nose pitched up, add clay ballast to the nose of the model. Once you have
adjusted the balance point proceed to glide test your model.
Glide test. The purpose of this test is to check the overall behavior of the model prior to using it under a
more powerful elastic launch. Do not neglect to perform this test as hard gymnasium floors are a
formidable opponent for the out of trim glider. Your scimon will not likely remain in one piece if fired into
the ground at full power! The scimon was designed as an indoor glider but will still perform well outdoors
in calm conditions. Perform this test in near zero wind conditions outdoors or pick a large indoor venue
such as an auditorium or gymnasium. Pick a point on the horizon just to the right (left for left-handed
launch) of the current wind direction (outdoors) and aim for it (this will result in a more level toss). With
wings level to the horizon, give the model a smart but gentle toss. Resist the urge to toss the model up or
shove it down.
Desired result: For models setup to launch right-handed. The model should glide in a lazy left-hand
turn and land at a near level attitude (Left-handed setup should produce a lazy right-hand turn).
If the models nose pitches up followed by an abrupt loss in both speed and altitude, the model is stalling.
Try adding a tiny amount of ballast to the nose and try your toss again. Likewise, if the model dives
abruptly you should try removing ballast from the nose and/or adding ballast to the tail.
Continue the glide test until you have achieved the desired result with your model.
If the model is not turning or gliding as expected, inspect your airframe for warps and proper assembly.
Model balance will generally control the gliders speed and stall. Stabilizer tilt will control glide circle as
will rudder to some degree (though rudder is really most effective at transition - more on that later).
First Flight
After a successful glide test it is time to try the model under power. The following instructions assume a
right-handed launch, directions for left-handed launch will be just the opposite as given with regard to
right and left designations.
Each flight can be broken into four distinct components setup, launch, transition, glide.
1. Setup. Launch angle and power are critical to a successful flight the scimon launches highest and
transitions best when the following launch angle and power setup is adhered to.
Grab your scimon and elastic launcher, with the launch stick held in your left hand and the
glider in your right; hook the loop end of the elastic through the launch lug (notch under the
ballast pocket at the nose of the glider).
Build Instructions
scimon 20 Build Instructions. © 2014 Stevens AeroModel all rights reserved.!Page 12

First Flight (continued)
With right hand, grasp the glider directly behind the vertical stabilizer on the bit of fuselage
that extends aft of the rudder. Pull the glider back against the elastic just enough to tension
the rubber and prevent the band from slipping off the launch lug.
Raise your left hand and outstretch your left arm out and away from your body.
Rotate the top of the scimon glider right, away from your body, so that the main wing is
nearly perpendicular to the horizon and the open portion of the “U” shape made by the
wings oriented to the right. While still grasping the glider drop your right hand down and
away from your body to build tension.
Observe three things prior to release: One, the angle of the elastic; adjust hand positioning
until the elastic and glider is inclined (aimed) at an angle of approximately 60-70 degrees.
Two, again take note of the glider rotation angle (near perpendicular to the horizon - top of
glider rotated away from body to right). Three, length of pull, build power slowly 24 inches
of stretch (distance from launch stick in left hand to launch lug on glider) should be plenty to
start.
Ready? Release!
Never launch scimon at another individual or when bystanders are not safely away from the
action. Flying gliders tends to attract the interest of children and pets. Keep these
individuals safe by keeping them involved or safely restrained away from the activity.
Never launch scimon with wings level at the horizon as the model will loop and potentially
crash nose first into the ground upon exit of the loop (infamous figure 9).
Never launch scimon with wings inverted (“U” opening to the ground) this will result in the
need to build a new scimon glider!
2. Launch. When setup, aimed, and released properly; your scimon will climb briskly in a tight right-
hand (clockwise) corkscrew pattern. Vary the amount of power input given in your setup to place the
flight apogee (the highest point of climb) as close to the celling as possible. High scores start with high
launches but don’t be tempted to shoot for the moon on your first flight. Build launch power as you
build flying experience.
3. Transition. As scimon approaches, and proceeds through, apogee it should be slowing to glide speed
and will flip or roll to the left beginning the glide stage of flight. A big stall (abrupt climb, nose drop,
and altitude loss) following transition can be indication that too much momentum was carried through
the transition, try reducing the launch angle by several degrees. Lack of altitude can be influenced by
input power on launch and launch angle, increase one or the other, one-at-a-time. While the transition
will be influenced by glider trim (especially the rudder angle) we have found it to be a mix of proper
glider setup and proper launch angle. Experiment with both until you can achieve consistent results.
4. Glide. After the left flip at apogee the scimon begins a descending left-hand (counter clockwise)
pattern until it lands. Your scores will be higher if you can trim scimon for a slow descent.
Congratulations on the first of many successful flights! At Stevens AeroModel we are committed to
improving your building and flying experience. We are constantly refining our processes, designs, and
manuals to reflect customer feedback. You may correspond with the Stevens AeroModel staff at:
email: [email protected]
Phone: [phone]
Build Instructions
scimon 20 Build Instructions. © 2014 Stevens AeroModel all rights reserved.!Page 13

Glider Trim Guide
Adopted from Don DeLoach’s HLG Trimming Chart
Glider Trim Guide
Adopted from Don DeLoach’s HLG Trimming Chart
Glider Trim Guide
Adopted from Don DeLoach’s HLG Trimming Chart
Points to keep in mind when prior to making trim changes.
•Trim guide will not correct a poorly launched glider. Follow guidance in “First Flight” for proper launch.
•Rudder controls the launch and transition.
•Stabilizer tilt controls the glide circle diameter.
•CG (balance) and Incidence (decalage) work together to control the models pitch or glide attitude and air speed.
Changes to incidence will often require changes to CG. Incidence has more of an affect on flight performance as the
speed increases. Thus you’ll change the incidence to solve looping during launch or nose diving after transition. CG
changes more subtly affect the aircrafts flying attitude and will often be made to affect flight speed.
Points to keep in mind when prior to making trim changes.
•Trim guide will not correct a poorly launched glider. Follow guidance in “First Flight” for proper launch.
•Rudder controls the launch and transition.
•Stabilizer tilt controls the glide circle diameter.
•CG (balance) and Incidence (decalage) work together to control the models pitch or glide attitude and air speed.
Changes to incidence will often require changes to CG. Incidence has more of an affect on flight performance as the
speed increases. Thus you’ll change the incidence to solve looping during launch or nose diving after transition. CG
changes more subtly affect the aircrafts flying attitude and will often be made to affect flight speed.
Points to keep in mind when prior to making trim changes.
•Trim guide will not correct a poorly launched glider. Follow guidance in “First Flight” for proper launch.
•Rudder controls the launch and transition.
•Stabilizer tilt controls the glide circle diameter.
•CG (balance) and Incidence (decalage) work together to control the models pitch or glide attitude and air speed.
Changes to incidence will often require changes to CG. Incidence has more of an affect on flight performance as the
speed increases. Thus you’ll change the incidence to solve looping during launch or nose diving after transition. CG
changes more subtly affect the aircrafts flying attitude and will often be made to affect flight speed.
Problem
Cause
Solution
Model loops on full power launch and
stalls often in glide.
Too much incidence (decalage)
Decrease incidence by warping
trailing edge of horizontal stabilizer
down.
Model pitches up steeply at launch
then nose dives into ground.
Too little incidence (decalage)
Increase incidence by warping trailing
edge of horizontal stabilizer up.
Model launches high with good
transition but stalls often in glide.
CG too far back
Add small amount of clay ballast to
nose until stall disappears.
Model launches high with good
transition but is fast in the glide and
slightly pitched down.
CG too far forward
Remove small amount of clay ballast
from nose of model until slower glide
is obtained.
Model glides nicely from level toss.
Launches are high but model fails to
consistently roll left* into transition.
Not enough left* rudder
Increase left* rudder by bending the
trailing edge of the fin left* until left*
roll out is obtained at transition.
Model rolls sharply to left* on launch
additionally, model does not launch
high.
Too much left* rudder
Decrease left rudder by bending the
trailing edge of the vertical fin right*
until launch is high and followed by a
“flip” or roll-out transition to the left*.
Model launches high and transitions
well but glide circle is tight (less than
than 20’ in diameter).
Too much stabilizer tilt.
Warp fuselage boom to decrease
horizontal stabilizer tilt until the glide
circle decreased to about 40’
diameter.
Model launches high and transitions
well but glide circle is wide (greater
than than 50’ in diameter).
Too little stabilizer tilt.
Warp fuselage boom to increase
horizontal stabilizer tilt until the glide
circle increases to about 40’
diameter.
Model launches high and transitions
well but glide tightens up into a tight
descending spiral.
Not enough wash-in
Check model for warps and wing
misalignment. Add additional wash-
in on left* wing panel till spiral is
reduced.
*Applies to right-handed launch. Left-handed launch will typically trim for the opposite direction.
*Applies to right-handed launch. Left-handed launch will typically trim for the opposite direction.
*Applies to right-handed launch. Left-handed launch will typically trim for the opposite direction.
Build Instructions
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