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- 49” 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
We highly recommend www.RCGroups.com as a good source for RC tips, tricks, and information.
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.

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Always follow manufacturer’s instructions for your radio system.
Always obtain proper insurance before flying – contact the AMA at www.modelaircraft.org
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
REQUIRED ITEMS
CA Glue – Thin and Thick
Polyurethane Glue (Gorilla, Sumo, or other)
Hobby Knife
Small Phillips Screwdriver
Set Metric Allen Wrenches
Scissors
Small Pliers
Clear Tape
Wire Cutters
Optional – Heat gun and covering iron
Assembly Instructions – Read completely before starting assembly!

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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.
Start by removing the tires from the rims, as shown. Apply medium or thick CA to the rim, all the way
around the tire mounting surface. Re-install the tires and allow the glue to dry. This is an important step,
since we do not want the tires to be able to roll off of the rims in the event of a cross-wind or otherwise
rough landing.

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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. Tighten
the locknut as shown to secure the assembly onto the gear leg. Only do ONE assembly at
this time.
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.

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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.
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.

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Make sure rudder horn is centered and apply several drops of thin CA to secure the rudder horn.
Install rudder onto fuselage and apply 2 large drops of thin CA to each hinge.
Assemble tail-wheel wire as shown

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Remove covering over tail-wheel wire slot in bottom of rudder.
Install tail wheel as shown. Use CA glue in slot, use two wood screws to secure bracket to fuselage, and
install tail wheel and secure with collar.

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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.

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Install wings without ailerons onto fuselage using carbon wing tube. NOTE – tube is packed in its travel
sleeve inside one wing bag. Install horizontal stabilizer into its slot as shown, align it side-to-side as
well as equalizing measurement from stab tips to wingtips as shown with tape measure. When stabilizer
is perfectly aligned, apply thin CA glue to the stabilizer–to-fuselage joint and allow to dry. Turn fuselage
over and apply thin CA glue to the bottom of the joint as well. If the gap between the stabilizer and
fuselage is not tight enough for thin CA glue to work well, follow up with medium or thick CA.
Install right side elevator, joiner will stick through as shown. Flex elevator to make sure you can get at
least 45 degrees throw, up and down. Use two drops of thin CA on each hinge.
Apply tape to the right side elevator balance as shown to hold the elevator perfectly straight.

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Apply medium or thick CA glue into the slot in the left side elevator as shown. Install elevator half,
holding perfectly straight (you can also use tape on this side as well) while glue dries. Apply 2 drops of
thin CA to each hinge.
Remove covering over elevator horn slot and install elevator horn as shown, using plenty of medium or
thick CA on the horn.
Remove covering over elevator servo opening. Attach 18-20” servo extension to elevator servo and
install as shown, with output shaft toward rear of airplane.

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Assemble the elevator pushrod (the longest of the three pushrods in the kit) as shown.
Install the elevator pushrod as shown, using 2mm bolts, washers, and nuts. Be SURE to
use medium or thick CA glue to lock the 2mm nuts in position. If you do not lock the 2mm
nuts with glue, they WILL vibrate loose.

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Assemble the rudder servo arm as shown. The connector nuts should be loose enough to allow the
connectors to rotate freely on the horn, use medium CA glue to lock the nuts into place permanently.
NOTE: 3DHobbyShop brand long servo arms are pictured.
The rudder pull-pull cable system is assembled as shown. Use medium CA to lock all nuts onto their
bolts, or they WILL come loose in flight.
Assemble the rudder ends of the cables as shown. Make the loop in the cable as shown before crimping.
Crimp the brass tube sleeve with pliers to secure the assembly. Crimp HARD to keep the cable from
sliding, then add a drop of thin CA to the crimp-joint. Use a drop of thin CA where the ball-link screws
onto the chrome end piece.

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Install the rudder ends of the cables as shown. Use medium or thick CA glue to lock the
2mm nuts. Feed the cables into the fuselage and to the front. Cross the cables once inside
the fuselage to make an X layout.
Use a piece of masking tape to hold the rudder perfectly straight.

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Mount the rudder servo as shown. Assemble the front ends of the cables as shown. Apply a drop of thin
CA to the completed crimps. Adjust the cables to be snug, but not too tight. “Banjo-string” tight cables
rob power from the servo. Tighten the set screw in the adjuster with a 1.5mm hex driver. Check your
cables after your maiden flight and after the first few flights. Adjust as necessary to remain snug.

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Assemble your brushless outrunner motor onto the firewall as shown. Nylon motor spacers are included
to space the motor away from the firewall if desired. Mount the ESC in the fuselage as shown, restraining
the wires with a zip-tie as shown
Tape strips of paper to the fuselage as shown to provide a guide to the location of the plywood-square
cowl mounts. Before installing the cowl, make sure the canopy-hatch is installed so you know everything
fits together.

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After locating the mounts, use a drill or hobby knife to make small holes in the cowl. Install wood screws
to retain cowl.
Align your ailerons onto your wings so that all the covering stripes match up, there is no need for a large
gap between the surfaces, 1/32 inch or 1mm is plenty. Apply two large drops of thin CA glue to each
hinge. Allow to dry.
Turn your wings over, locate the hole for the aileron servo and the slot for the aileron control horn.
Remove the covering over the hole and slot with a hobby knife or soldering iron. Install the aileron control
horns exactly as you installed the elevator control horn, with medium CA glue.
Install the aileron servos as shown. Trim the wing sheeting if necessary to clear your servos. Assemble
the aileron pushrods as shown. Use medium or thick CA glue to lock the 2mm nuts.
Assemble the airplane, use the 4mm black nylon thumbscrews to retain the wings onto the fuselage.
Self-adhesive Velcro is included in your kit, apply one side to your battery and the other to the battery
tray. Use the included Velcro strap around the battery to hold it tightly down to the tray.
Center of Gravity -
Balance your Sukhoi, preferably using a commercially-produced CG machine, or using your fingers is
necessary. For your first flights, balance your Sukhoi 100mm back from the leading edge of the wing
where is meets the fuselage. This is a good CG for precision flight. For 3D flying, you will want to move
your CG back. CG is a tuning point, and you should set it to suit your preference. For 3D flight, we prefer
a 110mm CG point, although this is less precise and stable in conventional flight than 100mm.

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The Sukhoi can use a variety of brushless outrunner motors weighting 150-200 grams. If your motor is at
the light end of this range, expect to add nose weight to balance the aircraft.
Control throws and exponential –
We suggest using high and low rates on the ailerons and elevators. We typically only use high rates on
the rudder, with plenty of exponential. Control throws are given in both degrees, and millimeters of travel
measured at the end of the surface (where the movement is farthest). “Max throw” means to set the
controls for the largest throw possible.
Ailerons - Low 17 degrees / 25mm 30% expo
High 30 degrees / 42mm 70% expo
Elevator- Low 17 degrees / 35mm 30% expo
High Max throw, must be at least 45 degrees 70% expo
Rudder- High Max throw without touching elevators 85% expo
Make your first flight with the controls set on low rates. During the trimming phase, we recommend
landing with some throttle, not attempting to “dead stick” the airplane. This may mean you need to time
your flights and keep them a bit shorter than usual. After your first flights, check all control connections
and motor and prop mounts for tightness.
Check your rudder pull-pull cables for tightness at the beginning of each flying session. Pull-pull cables
tend to loosen a bit over time, and loose pull-pull cables (cables that flop, or have sag, or that allow you to
move the rudder with your hand without the servo arm moving) are a major contributor to poor aerobatic
performance.
Periodically inspect the battery tray area in your aircraft. This plane does excellent high-speed tumbling
maneuvers, and this type of maneuver puts tremendous stress on the battery tray area. Occasionally
adding a bit of CA glue to the battery tray joints will help your aircraft last through hundreds and hundreds
of flights.
Your Sukhoi kit contains a decal sheet. Cut out the decals with scissors or a hobby knife and install them
dry onto your Slick as desired.
Flying notes:
Your Sukhoi has a very powerful rudder. In 3D flight, it is very important to be gentle on the rudder stick.
If you are gentle with rudder application in harrier flight, your Sukhoi can be harriered without wing rock.
Too much rudder will cause the wings to dip on the side the rudder is deflected toward.
At landing, leave your throttle at 1/8th or a little higher, and fly the aircraft all the way to the ground – do
not flare until the aircraft is very low, knee-high or lower. In this way, you will avoid stalling.
We hope you enjoy your 3D HOBBY SHOP Aircraft.
Be sure to look for new aircraft and products coming soon from
3 D H O B B Y S H O P . C O M

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Copyright 2008 3D Hobby Shop