Stevens Aero Model GYM-E User manual

© 2008 Stevens AeroModel. Page 1 of 11
GYM-E
Original Design by Todd Long
Instruction Manual - Version 1.03
Span 31 in. / Length 27 in. / Area 265 Sq. In. / Weight 4.5-6.5 oz.
Gym-E kit reproduced with permission by Stevens AeroModel

© 2008 Stevens AeroModel. Page 2 of 11
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. Stevens AeroModel reserves the right to change or modify this warranty without
notice.
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 the use by
the user of the final user-assembled product. 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.

© 2008 Stevens AeroModel. Page 3 of 11
REQUIRED TO COMPLETE KIT:
Kit Contents:
Rolled computer drawn Plan Sheets
Illustrated Instruction Manual
Laser Cut Parts Inventory (on next page)
1 – 5mm x 19-5/8” Carbon Tube
1 – 1/32” ID x 18” length push rod housing
2 – 1/4“ x 18” length balsa dowel
2 – 5/16” x 18” length balsa dowel
2 – 1/32” x 18” length music wire
1 – 1/16” x 18” length music wire (heavy gauge landing gear)
1 – 0.047” x 18” length music wire (optional lighter landing gear)
Hardware Bag
•2 – DuBro RC Micro EZ-Link (DUB849)
•2 – DuBro RC Micro Control Horns (DUB848)
•2 – DuBro RC Mini E/Z Connector (DUB845)
•2 – 1.5” Spindle Wheel (GW/WH01/38)
•1 – Package Gum Rubber Bands #16 (GW/AP012)
•1 – 1/8” x 3” Length Hardwood Dowel
•1 – 1/16” Laser Cut brushless motor mount
Recommended Finishing Items:
1. 1 Roll of Stevens AeroModel AeroLITE low temp light weight covering film.
2. 1 Roll Clear Tape (MMM190)
Required Electronics:
1. 2 – Sub Micro Servos (Designed for: JR S-185, JR SM8, or HS-50)
2. 1 – Micro Receiver (Berg MS4L)
Power System:
1. 1 – GWS IPS “A” Gear Drive (GW/IPS-DX2BB-AXCS)
2. 1 – EHS-50 Heatsink (optional)
3. 1 – 2-5A Electronic Speed Control (Castle Creations Pixie 7P)
4. 1 – 250mAh (6c) 7.4V LiPo (Stevens AeroModel OEM250)
5. 1 – 10x4.7 Slow-Fly Propeller (GW/EP1047)
Notes on brushless power systems. Having flown this delightful model on the affordable brushed power system
recommended above we cannot see where the model or hobbyist would benefit from brushless power. In fact, if the
wrong brushless system is installed in this model there is a serious chance of over speeding and damaging the airframe.
Should you still elect to install a brushless power system be mindful of obtaining a motor, battery, esc combination that
exactly replaces the weight of the original brushed system above (about 52-54g) swings a propeller with a diameter in the
range of 7-10 inches and does not produce a pitch speed greater than 25mph.
Items You Will Need:
1. Thin CA (super glue)
2. Medium CA (super glue)
3. #11 and Straight Edge Razor Blade(s)
4. T-Pins
5. Fine Grit Sand Paper and Sanding Block

© 2008 Stevens AeroModel. Page 5 of 11
Fuselage Assembly
The bulk of the fuselage is assembled from 1/32” plywood. We have intentionally made the fit a bit loose as the
parts are somewhat delicate until the assembly is complete. Thus we suggest using a medium weight CA glue to
bond the fuselage parts of the Gym-E. NHP Flash Medium or Mercury 100XF CA glues work very well here. All
parts are 1/32” ply unless otherwise stated and interlock at right angles. Prior to bonding check/align parts for
perpendicular fit.
1. Begin “Forward Wing Mount”. Locate the 1/32”
ply parts M1 (only one required for this step)
and M4. Key parts as illustrated on left then
bond with CA glue.
2. Locate the M10 battery tray and key to previous
assembly as illustrated below then bond with
CA glue.
3. Locate the second M1 component and key to
assembly as illustrated then bond with CA glue.
4. Locate one of the M9 landing gear supports and
key to the assembly in the forward most slot
provided in the wing mount. Retain M9 with CA
glue. DO NOT INSTALL THE SECOND M9
COMPONENT TO THE AFT SLOT AT THIS
TIME.
5. Locate M5 and key to top of wing assembly as
illustrated. Square assembly then bond M5 with
CA glue.

© 2008 Stevens AeroModel. Page 6 of 11
6. Assemble IPS motor mount stick from a
lamination of 1/32” ply and 1/16” balsa parts as
illustrated. Laminate in the following order: M2,
M3, M3, M2 to create the motor mount stick.
Next, install the completed stick to the Forward
Wing Mount centering the stick to the mount as
illustrated.
7. Begin “Rear Wing Mount” and servo tray. Key
parts M6 (only one required) and M7 together
as illustrated. Bond with CA glue.
8. Locate the S1 servo tray and key to assembly.
Note pay particular attention to the drawing on
the plan sheet and the photo to left properly
position S1 servo tray so that it extends forward
of the Rear Wing Mount. Bond S1 with CA glue.
9. Locate the second M6 component and key/bond
to assembly as illustrated.
10. Bond M8 to top of assembly as illustrated.

© 2008 Stevens AeroModel. Page 7 of 11
11. Locate the 3/32” balsa parts marked A1 and A2
(these parts resemble an elongated “C”) and
install within the wing mounts to the underside
of M5 and M8 respectively. Study the plan set
for proper orientation of these parts. The
pocket formed by the “C” cut-out will capture the
wing mounting dowels thus, it is important that
the “C” shape opening in A1 faces towards the
motor mount stick when installed within the
Forward Wing Mount. Conversely the opening
in A2 should face opposite the servo tray, or
towards the rear of the model, when installed
within the Rear Wing Mount.
Example photos on the left details A2 and
installation in Rear Wing Mount.
12. Cut the provided 1/8” hardwood dowel stock to
the following lengths to form the front and rear
wing mounting dowels:
Front - cut to 7/8”
Rear – cut to 1-1/8”
Sand round one end of each of the wing
mounting dowels. Then, install the short and
long dowels to the front and rear, respectively,
wing mounts.
(The top photo at left shows the dowel being
seated and bonded within the Rear Wing Mount
assembly. The bottom photo at left shows the
dowel installed within the Forward Wing Mount.)
This completes the Forward and Rear Wing
Mount assemblies. You should now have two
assemblies that look identical to the illustration
on Left.
13. Slide both the Forward and Rear Wing Mount
assemblies on to the pre-cut 5mm carbon tube.
THERE IS NO FORWARD STOP where the
carbon tube installs within the Forward Wing
Mount, instead, align the leading edge of the
carbon tube with the leading edge of M4 within
the Forward Wing Mount. With the Forward
Wing Mount properly positioned adjust the
position of the rear wing mount so that the
distance measured from the leading edge of M5
and trailing edge of M8 are exactly 9-1/4” apart.
Finally, set the assembly inverted on top of your
flat work surface to align the wing mounts and
bond to the carbon tube at all contact points
with Thin or Medium CA glue.

© 2008 Stevens AeroModel. Page 8 of 11
14. With the fuselage still inverted on your work
table bond the part S2 to the center of the servo
tray as illustrated on Left. S2 sets the thickness
of the servo bracket and only one S2 part
should be required if you intend on running the
suggested servos. For compatibility with servos
featuring thicker mounting tabs we have
provided an additional S2 part which may
accommodate various un-supported servos on
the market.
15. Complete the servo tray by bonding S3 on top
of S2 and centered/aligned with the cut-outs in
S1.
16. Use the plan set as a guide and bend the
provided 1/16” music wire to match. Note that
we have included a length of .047” music wire
which you may substitute for reduced weight at
the expense of reduced ground handling.
With the wire landing gear properly bend slide
over the aft section of the Forward Wing Mount
in-front-of the receiver tray. The landing gear
should seat flush against the previously installed
M9.
Now install the second M9 component from the
bottom up. Bond to assembly with CA glue.
Finally, wick CA glue along landing gear wire
within M9 parts to retain gear.
17. Slide included spindle wheels over landing gear
axel then bend / cut excess wire as illustrated to
retain wheel.
Note that hub of spindle wheel must be drilled to
fit 1/16” music wire landing gear. No drilling will
be required for lighter .047” music wire gear.

© 2008 Stevens AeroModel. Page 9 of 11
V-Tail Assembly
Use the plan sheet as a guide to reference parts layout for V-Tail assembly. The design of the V-Tail assembly utilizes
the Stevens AeroModel TrusLoc™ interlocking balsa truss. All V-Tail components are located on the 3/32” balsa sheet
labeled GYME-SA 02/04.
1. Begin by assembling the outside frame for the control surface. Next, fill in with the interlocking truss
components. Note that the truss components are etched “A”, “B”, etc. the methodology we use for assembly is
“A” to “A” and “B” to “B” etc. As there is always a slight angular component to parts cut with a laser we suggest
that, when possible, you invert one of the interlocking parts for a more positive fit (one part etched side up –
interlocking part etched side down).
2. Bevel the leading edge of the elevators at 45
degrees, relative to your building board, in
preparation for tape hinges. Note: When
sanding in your bevel MAKE A RIGHT AND
LEFT ELEVATOR.
Illustration shows properly sanded LEFT side
elevator. Note that top surface of elevator
should be flat with bevel tapering aft.
3. Cover both the stabilizer and the elevator.
Remove ¼” of covering from the inside edge of
both the right and left stabilizer. Next use the
provided stabilizer jigs to set the angle of the
stabilizer relative to your flat building board.
Next block sand the inside edge of the
stabilizers so that when held together at the 110
degree angle the root surfaces fit flush.
Illustration shows completed Right stabilizer.
4. Temporarily tape the completed stabilizer and
elevator to your flat work surface, setting the
gap between the parts to 1/32”. Note that flat
side of elevator should be on top with beveled
side of surface facing building board. Now,
apply a length of clear tape along the joint of
stabilizer and elevator. Remove / trim excess
tape to edge of assembly to complete top side
of tape hinge.
5. Release from work surface, fold the hinged
surfaces back on each other until the beveled
surface of elevator is flush with perpendicular
inside edge of stabilizer. Now apply tape along
joint and trim. This completes the underside of
the tape hinge.
This completes the V-Tail assembly. See
“Final Assembly” for further instruction.

© 2008 Stevens AeroModel. Page 10 of 11
Wing Assembly
The wing is of conventional build. To complete this assembly you’ll need a building board, T-Pins, plan sheet, and
plan protector. We will use medium CA throughout the build. Drop ceiling tiles are readily sourced at most DIY
home centers and make excellent building boards. Plans protection is easily accomplished by using the poly tubing
that this kit shipped in, cut the sealed end of the tube off then make a cut down it’s length and flatten out for a very
CA resilient plan protector.
Set your building board atop your flat work surface, tape the provided plan set on top of the building board, cover
plan set with your poly tubing plan protector. T-Pins at the ready? Let’s get started!
1. Start the wing by laminating a few ribs. Take two R4 ribs and laminate them together. Repeat once more so you
have two sets of two R4 ribs glued together. Take two R1 ribs and laminate them together. Repeat once more
so you have two sets of two R1 ribs glued together. Set laminated ribs aside.
2. Build the center section first by cutting the 5/16” balsa dowel leading edge to length and pinning to the plans.
Take the remaining six R1 ribs, position and glue them in place making sure they are pinned flat to the building
board. MAKE SURE THE RIBS ARE PLACED IN THE CORRECT ORIENTATION WITH THE HIGH POINT
TOWORDS THE DOWEL, SEE PLANS. Cut to length and glue the ¼” balsa dowel to the rear of the ribs.
3. Assemble the 1/16” R4 wing center section sheeting from R5a, R5b, and R5c. Glue the 1/16th R5 sheeting in
place spanning center R1 ribs as detailed on the plan set. Let glue cure, and then remove the center wing
section.
4. Now build the left and right outer wing panels using ribs R2, R3, and the laminated R4 ribs in similar fashion to
the center section. Raise the outer wing panel using the provided leading and trailing edge jigs then sand in the
correct dihedral angle at the leading and trailing edge dowels at outer wing panel root. It is very important to get
the correct angle sanded so there is a perfect fit with no gaps between the center wing section and outer wing
panels. See the picture above to see the easiest way to do this.

© 2008 Stevens AeroModel. Page 11 of 11
5. Pin the center section down and glue the outer wing panels (one at a time) to the center section supporting
each tip using the provided leading and trailing edge jigs. Glue the laminated R1 ribs in place over the joint
where the outer wing panel and center section come together (laminated R1 should be oriented parallel to joint).
Sand any rough spots on the wing in preparation for covering.
Final Assembly
1. Complete the wing by covering with AeroLITE™ by Stevens AeroModel according to the instructions provided
by the covering manufacturer. Only the top surface of the wing needs to be covered. Note: Be careful not to
warp the wing by shrinking the covering material too tight. We find it easier to cover the wingtips first then the
center section.
2. Attach the wing to the fuselage with two (2) #16 rubber bands to and use as a guide make square the V-Tail
stabilizer to the fuselage and wing. Secure the V-Tail stabilizer using medium CA glue.
3. Cut the provided 1/32” id plastic push rod housing into 9” lengths and tape them to the carbon boom as
illustrated on the plan sheet. Install the DUB845 Mini E/Z Connectors on the outer holes on your servos. Slide
the JR S185 servos within the servo tray and retain by looping a rubber band around the servo body and tray at
the servo mounting tabs. Cut the provided 1/32” music wire to length and form into pushrods using the plan
sheet as a guide. Slide the completed push rods through the tubes from the rear (with the “L” bend at rear of
fuselage) then through the DUB845 Mini E/Z connectors on the servos. Remove a little of the covering around
the holes where the DUB848 Micro control horns will attach. Attach the pushrods to the control horns with the
DUB849 Micro E/Z Link. Now mount the control horn into the elevator halves and glue them in place so they
follow the natural contour of the pushrod. Once the glue has setup for retaining the control horn, clip the excess
post from the back side of the control horn.
4. Mount the motor and ESC. If the motor fit is loose then build up a thin layer of CA glue on the motor stick, allow
glue to cure, then re-fit motor to stick (repeat until motor is a snug fit). Place a piece of Velcro under the M10
battery holder (not provided). The Velcro comes with adhesive but we still like to glue it on with a little CA.
Attach the opposite piece of Velcro to the LiPo battery and place the battery onto the battery mount.
5. Mount the receiver under behind the Forward Wing Mount on the tray provided and run the antenna to the rear
of the plane (For 72mHz systems we suggest the use of an Azarr M72-I base loaded antenna). Now mount the
wing to the fuselage. Make sure everything the plane needs to fly is now mounted and installed. The plane
should balance between 3” and 3 ½”behind the leading edge. CG changes can easily be made by shifting
electronics or using a small amount of modeling clay in either the nose or tail.
6. Make sure both the servos and elevators are electronically centered in your radio programming. Now, center
the control surfaces at the V-Tail. Next, cut the remaining pushrod wire so they extend about 3/8” beyond the
connectors. Finally, snug the set screw on the DUB845 Mini E/Z Connectors.
7. Follow the manufacturer’s instructions for the transmitter and set it up for elevon mixing. When you pull back on
the stick both elevators should move up, opposite when you push on the stick. When right stick is applied both
elevators should move to the right when behind the model, opposite for left stick. If you do not get this
movement then make adjustment at your transmitter or swap the servo connectors at the receiver. When up
elevator is applied you should have about ½” to ¾” inches of travel.
8. Set up the ESC according to you manufacturer’s instructions, check the CG again, charge the battery and go
fly.