3D Hobby Shop 49 Sukhoi 26MX User manual

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3 D H O B B Y S H O P . C O M
Assembly Manual- 57” Sukhoi 26MX
Thank you for purchasing this 3DHobbyShop ARF RC aircraft. If you have any issues, questions,
concerns or problems during assembly, please contact our tech department at:
[email protected] or 1-830-990-6978 10am-5pm Central M-F
SAFETY in Assembly
During assembly of this aircraft, you will be asked to use sharp knives and hobby adhesives. Please
follow all safety procedures recommended by the manufacturers of the products you use, and always
follow these important guidelines:
ALWAYS protect your eyes when working with adhesives, knives, or tools, especially power tools. Safety
glasses are the best way to protect your eyes.
ALWAYS protect your body, especially your hands and fingers when using adhesives, knives, or tools,
especially power tools. Do not cut toward exposed skin with hobby knives. Do not place hobby knives on
tables or benches where they can roll off or be knocked off.
ALWAYS have a first-aid kit handy when working with adhesives, knives, or tools, especially power tools.
ALWAYS keep hobby equipment and supplies out of the reach of children.
IMPORTANT NOTE – We strive to provide the absolute best-quality ARF aircraft on the planet. However,
the ultimate success or failure of this aircraft is dependent upon proper assembly by you. If you have
questions about an assembly step, please contact us, or read the assembly thread for your airplane on
RCGroups.com before proceeding. It is always better to slow down and be sure of your assembly than to
rush through it and make a mistake which can cause a crash.
SAFETY in Flying
SAFETY NOTICE: This is NOT a toy! It is a very high-performance RC airplane capable of high speeds
and extreme maneuvers. It should only be operated by a competent pilot in a safe area with proper
supervision.
ONLY fly your aircraft in a safe, open area, away from spectators and vehicles–and where it is legal to fly.
NEVER fly over an unsafe area, such as a road or street.
NEVER fly near overhead power or utility lines. If your airplane ever becomes stuck in a line or a tree DO
NOT attempt to retrieve it yourself. Contact the authorities for assistance in retrieving your aircraft.
Power lines are DANGEROUS and falls from ladders and trees CAN KILL!
Never fly too close to yourself or spectators. Spinning propellers are DANGEROUS!
Never run your motor inside a house or building with the propeller attached – Remove the prop for safety.
Always fly within your control.
Always follow manufacturer’s instructions for your radio system.
Always obtain proper insurance before flying – contact the AMA at www.modelaircraft.org

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Developer’s Note
As a full-size Sukhoi pilot, one of my dreams has always been to see my airplane, N25SU, in
model form. That dream got a little closer to reality when I started doing model development for
3D Hobby Shop in 2006. At some point in late 2007, both Ben and I made a commitment to
model the Sukhoi. Setting our sights rather high, we aimed to design what would be the premier
Sukhoi model on the market, incorporating not only outstanding flying characteristics, but also
many of the scale features rarely seen on Sukhoi models. We were able to accomplish both of
those goals, and much more. I am proud to introduce the 3D Hobby Shop Sukhoi 26 in two
distinct sizes – 49” and 57”.
For me, the Sukhoi represents the ultimate aerobatic experience. Its combination of beautiful
sculpted lines and aggressive stance make it one of the most distinct airplanes on the competition
circuit. Designed in the mid 80’s, the Sukhoi 26 was created for one purpose, and one purpose
alone – to dominate world aerobatic competition. Dominate it has, amassing more Gold
International medals than all other designs combined. We wanted to design a model that captured
that aggressive precision attitude, while combining it with unlimited 3D/freestyle performance.
The 3DH Sukhoi’s clean lines allow great tracking, while the thin 10% airfoil allows great pitch
performance and fast cruising speeds. Oversized control surfaces make the Sukhoi one of the
most responsive 3D airplanes on the market. The roll rate, in particular, can be absolutely
blinding. Unlike the full size Sukhoi, the 3DH version has only light coupling in KE flight, and
only very light wing rock upright, none inverted. Typical of all 3DH airplanes, the Sukhoi
incorporates all of the high end accessories you’ve come to expect including a carbon wing tube,
carbon landing gear, tool-free wing attachment, slotted self-aligning wheel pants, and a complete
hardware pack. In all, I feel the 3D Hobby Shop SU-26 is the ultimate Sukhoi RC model airplane
available today.
-Scott Stoops
3D HOBBY SHOP

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REQUIRED ITEMS
CA Glue – Thin and Medium or Thick
Hobby Knife
Small Phillips Screwdriver
Set Metric Allen Wrenches
Scissors
Small Pliers
Masking tape
Wire Cutters
Drill and drill bits
Optional – Heat gun and covering iron
Threadlocker (Blue Loctite)
For Glow Fuel Engine –
Fuel tubing
Large Zip-ties
Foam rubber pad
30-minute epoxy glue
Disposable paintbrush
Fuel-dot (recommended)
Assembly Instructions – Read completely before starting assembly!
UNPACK
Unpack your airplane and examine the components. Check for damage of any kind. If you have
damage, please contact 3DHobbyShop to discuss.
WRINKLES
Your airplane was packed in plastic at the factory without any wrinkles in the covering. You may notice
some wrinkles now; more likely, you will notice a few in a day or two or the first time you take the plane
out to the flying field. These wrinkles are the result of wood shrinkage and/or expansion. Balsa wood
changes size and shape slightly as it is exposed to varying humidity in the air. This is a natural property
of balsa wood. As your airplane adjusts to the weather in your part of the world, wrinkles may appear and
disappear. Wrinkles may be removed with the gentle application of heat to the covering material on your
airplane. The best tools to use are a heat gun and covering iron. Apply the heat gently: the covering
material will shrink as you apply the heat, and this will remove the wrinkles. BE CAREFUL! Too much
heat applied too quickly can damage the covering, either by causing it to pull away from the wood at
seams and corners or even by melting it. The covering will shrink at low temperature with patient
application of heat. Wrinkles in the covering DO NOT affect flight performance. If you must shrink on
a color-seam, use the iron and go slowly and carefully to avoid any pulling or lifting at the seam.
Remove the canopy before attempting to use heat on your covering! The canopy is made of thermo-
activated plastic and WILL deform with the application of heat. Do not apply heat to the canopy.
PAINT
If you need to clean your airplane, we recommend using a damp towel. The paint used on the canopy
and cowl is not safe for all cleaners. In particular, DO NOT use alcohol on these parts, it will remove the
paint.

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Install the wheels onto the axles and secure with the wheel collars, as shown.
Slide one wheel/axle assembly into a wheel pant, and install the wheel assembly on the
landing gear leg. Tighten the locknut as shown to secure the assembly onto the gear leg.
Only do ONE assembly at this time.

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Install one wood screw through the gear leg into the wheel pant as shown, going in half-way. Remove
the screw, cut ½ of the screw off with wire cutters, and re-install as shown.
Slide the gear leg through the slot as shown, and secure the gear to the fuselage with short 3mm screws.
Repeat wheel and pant assembly for other side.

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Locate rudder, remove covering over rudder control horn slot with hobby knife or hot
soldering iron. Insert double-sided rudder horn into slot as shown.
Make sure rudder horn is centered and apply several drops of thin CA to secure the rudder horn.
Measure back 2.5” from the hinge line on the bottom of the rudder. This is where we will install the tiller
guide for the tailwheel. Mark this location.

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.
Drill a 1/16th inch hole on your mark, and install the tiller holder with thick CA glue.
Install rudder onto fuselage and apply 2 large drops of thin CA to each hinge.
Install tail wheel as shown. Use two wood screws to secure bracket to fuselage. Remove the set screws
in the tailwheel assembly, apply loctite and re-tighten.

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Remove covering over cooling outlets on bottom of fuselage, as shown.
Remove covering as shown from horizontal stabilizer opening and rudder pull-pull wire slot.
Remove covering from the elevator servo opening on the left side of the fuselage as shown.
Install the wings (without ailerons) NOTE: the wing tube is packed in its travel holder inside
one of the wing bags. Use a tape measure to square the stab up with the wings and
fuselage, equalizing the measurements right to left as shown.

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Once the stab is aligned, apply thin CA glue to the joint, top and bottom. Note that we do
not cut into the covering of the horizontal stabilizer for this type of installation. CA glue
bonds very well to covering material. If your stab joint is not tight enough for thin CA glue,
or if you have to trim the opening to align the stab, you can use thick CA glue as well.
NOTE: Elevator servo options.
Your 57” Sukhoi can be built with single or dual elevator servos. For duals, use Hitec Hs-
225MG or Hs-5245MG servos. For a single, you can use one Hs-225MG or Hs-5245MG, or a
full-size servo.
Dual elevator servo installation
Remove the covering over the elevator horn slots and use a generous amount of CA glue to
install the elevator horns in both elevators as shown.

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Install both elevator halves as shown. Make sure you can flex the elevators easily 45
degrees up and down before gluing each hinge with a few large drops of thin CA glue.
Install the elevator servos on each side as shown.
Assemble the elevator pushrods as shown. Once you have assembled the ball links onto the
pushrods and checked their lengths for perfect fit, apply thin CA glue to the ball-link to
pushrod threaded joint. Use the 2mm bolt with washer and nut to attach the pushrod to the
servo arm and control horn.

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When you have installed the elevator pushrod as shown on each elevator half, be SURE to
use medium or thick CA glue to lock the 2mm nuts in place. IF you do not lock the 2mm
nuts holding the pushrods, the nuts will vibrate loose and your plane WILL crash.
END of dual elevator servo install section.
Single Elevator servo installation
Remove the covering from the inner hinge area of each elevator as shown. There is a loose
balsa filler piece under the covering. Remove it as shown, opening up the elevator joiner
slot in the elevators.

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Locate the phenolic elevator joiner and the left elevator.
Use a generous amount of CA glue to install both the joiner and the elevator control horn
into the left elevator as shown.
Insert the elevator into the stabilizer, make sure it flexes easily 45 degrees up and down,
and glue the hinges with large drops of thin CA glue. Apply a piece of masking tape to the
left elevator half to hold it perfectly straight.

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Apply a generous amount of medium or thick CA glue to the slot in the right elevator and
install the right elevator onto the stab with thin CA on the hinges. Hold perfectly straight as
the glue dries, or use masking tape to hold the elevator straight until the glue dries.
If you are using a single HS-225MG (or 5245MG) then you can install it into the elevator
servo slot. If you are using a full-size servo, use the included template to mark the hole for
trimming as shown. Trim the template as necessary to clear the stab.
Use a sharp, new hobby knife to trim the excess wood. Use many light strokes with the
knife, don’t press too hard into the wood. Be patient. Mount the elevator servo with the
output shaft to the rear of the plane.

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Assemble the elevator pushrod as shown, using the carbon tube stiffener. Once the
elevator pushrod is assembled and the length checked for accuracy, use thin CA on the
joints of the carbon tube and ball links to lock the assembly together.
Use 2mm bolts, washers and nuts to assemble the pushrod onto the servo arm and elevator
horn as shown. Be SURE to use medium or thick CA glue to lock the 2mm nuts in place. IF
you do not lock the 2mm nuts holding the pushrods, the nuts will vibrate loose and your
plane WILL crash.

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Route elevator servo wire (or wires) as shown to keep them away from the rudder pull-pull
wires.
Mount the rudder servo as shown.

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Assemble the ball links and pull-wire ends onto the rudder horn as shown with 2mm bolts,
washers and nuts. Be SURE to lock the nuts with medium or thick CA glue. Install the
rudder servo arm onto the servo. Screw the pull-cable ends into the ball joints several
turns, but not all the way – this is your adjustment to re-tighten slack pull-pull cables.
Use masking tape to hold the rudder perfectly straight.
The rudder pull-pull cables are assembled as shown in the above diagram.

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Assemble the pull-pull wires onto the rudder horn as shown, double-looping the wire
through the bras crimp, sleeve. Crimp the brass crimp sleeve tightly with pliers and apply a
drop of thin CA to the crimp. Be SURE to use medium or thick CA to lock the 2mm nuts on
the rudder control horn. Feed the wires into the fuselage slots and forward to the front of
the fuselage. Cross the wires once so they make an X inside the fuselage.
Again, screw the pull-cable ends into the ball joint several turns, but not all the way, leave a
couple of threads of adjustment.
Assemble the front ends of the pull-pull cables as shown, double looping the wire through
the crimp sleeve. You want your pull-pull cables to be snug, with no sag, but not too tight.
“Banjo-string-tight” pull-pull cables only sap the power from your rudder servo and cause
poor handling. Just snug is all you need.

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When you are satisfied with the fit of both pull-pull cables, crimp the sleeves tightly, apply a
drop of thin CA to each sleeve, and cut off the excess cable.
Electric Motor Install
Using included 4mm allen head bolts, attach the electric motor mount to the firewall as
shown. Note that the mount is marked with U for UP, R for Right, D for Down, and L for
Left. Use threadlocker compound on these screws.

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Drill the motor mounting pattern as needed and mount your brushless motor as shown,
using threadlocker.
Mount the ESC as shown and restrain the wires with zip ties.
Glow engine install
Install notes: The structure of the 57” Sukhoi is designed very light, and requires
reinforcement to withstand the vibration of a glow engine. Also, the structure needs to be
sealed against oil and glow fuel. Follow the following procedures exactly to install your glow
engine, and do not skip any steps.

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Use CA glue to install the plywood pieces that overlay the front of the fuselage as shown.
DO NOT install the motor box top piece at this time, because we will need access to the
inside of the box for several more steps. Place the varnished side of the wood to the
outside.
Mix up a generous portion of 30-minute epoxy glue, and use a disposable paintbrush to
apply it all over the outside of the motor box.