Durafly PRIME TUNDRA User manual

INSTRUCTION MANUAL
Please read this manual carefully before operating this plane.
DURAFLY PRIME TUNDRA 1200MM
READY TO FLY VERSION

WARNING
SAFETY PRECAUTIONS
Read this instruction manual fully so as to become completely familiar with the features of the product before
operating. Failure to operate this product correctly could result in damage to the product, personal property
and cause serious injury. This is a sophisticated hobby product and is NOT a toy. It must always be operated
with caution, common sense and some basic mechanical ability. This manual provides instructions on the
assembly, safe operation and maintenance of this hobby product. It is highly recommended that you read and
follow fully the instructions and warnings stated in this manual including safety, assembly, set-up and flying
guidelines in order to operate this product correctly and avoid damage or serious injury.
As the user of this product you and you alone are responsible for operating it in a manner that does not
endanger yourself and others around you or result in damage to the product or property of others. This product
is operated via a radio controlled system that in some cases can be subject to interference from sources
outside of your control. Interference may result in a momentary loss of control so it is always recommended
that this product be used in a suitable open outdoors space.
• This is a radio controlled flying model and as such must always be flown with caution, this is NOT a toy.
• The H-King J3 Swiss Cub brief was to design a model for low hours to intermediate pilots.
• Always exercise great caution when using the recommended battery to power this product. For full safety
notes and operating procedures please read the information provided by your battery supplier.
• Take great care when connecting/disconnecting the battery. Once again see your battery suppliers informtion
for the full safety procedures.
• Never power up the model in a confined space and always keep the propeller clear of obstructions, clothing
and parts of your body.
• This product is not a toy, children must be accompanied by an adult at all times when operating this product.
• Only fly this model in an open area away from crowds, people, buildings, trees, power lines, roads, airports
and other obstructions.
• Always put safety first when operating this model and consider the warnings stated above.
• The supplier/manufacturer accepts no responsibility for damage or injury caused through the use of this
product. A reminder that it is not suitable for children under the age of 14. THIS IS NOT A TOY.

Thank you for purchasing the Prime Tundra, it is yet another addition to the extremely popular Tundra
series of STOL (Short Take Off and Landing) airplanes from Durafly, but this one is aimed primarily,
but not exclusively at the novice. It is also the perfect STOL trainer for those that want to get into this
style of flying as it inherits the excellent STOL flying characteristics of the Tundra lineage including the
large Tundra style flaps, it's a lot of fun for the seasoned Tundra fans to! It is the most stable Tundra
to date even without a gyro, but coupled with the pre-installed ORX 3-axis gyro it is taken to another
level. The Prime Tundra is the perfect choice for a very first RC airplane due to its rugged and simple
lightweight construction, fast and easy assembly with no gluing, but mainly because of its superb, and
very benign handling characteristics, making it the most stable and sedate of the Tundra family.
The PT1200 is supplied with the exact same tried and tested big wheels from the original Tundra
which makes them perfect for every type of surface, be it a runway or a mountain track. This makes
the Prime Tundra a very versatile aircraft, and that versatility extends to the wing mounting system
too. The PT1200 is supplied with a 'Bolt or Band' wing mounting option. We recommend using the
elastic band on wings if you are a novice and the bolt on system for those more experienced fliers.
Another great feature is that it has the option for floats making it perfect as your first choice of
floatplane. This version of the Prime Tundra is supplied RTF (Ready To Fly), this means it comes
complete with everything you need except for a flight battery, flight battery charger, and some "AA"
batteries. It is supplied with an easy to use Turnigy T-6A 6 channel transmitter and receiver, 3-Axis
ORX gyro, motor, ESC, and 6 digital servos, all these items are preinstalled at the factory.
So if you are looking at starting RC model flying then look no further than the Prime Tundra, it is the
perfect choice. But also, the Prime Tundra is a fantastic sports aerobatic/ STOL plane with a flight
envelope that will appeal to the most discerning pilot. Learning to fly has just become a lot more fun
for novices and their instructors with the Prime Tundra.
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INTRODUCTION:
- Wing span: 1200mm (47.2”)
- Length: 950mm (37.4”)
- Flying weight: 950g (33.5oz)
- Motor: 3542 800kv Brushless outrunner
- Controls: 6-Channels (Throttle, Ailerons, Elevator, Rudder, Flaps, and Gyro)
- Battery: 1300~1400mAh 11.1V 3S LiPo 25C or more (not supplied)
- Propeller: 10”x6”
- Servos: 6 x 9g Digital
- ESC: Aerostar RVS 30A Brushless
- Radio system: Turnigy T-6A Transmitter and Receiver
SPECIFICATIONS:
DURAFLY PRIME TUNDRA 1200MM
READY TO FLY VERSION

CONTENTS:
1. Fuselage
2. Wing
3. Horizontal Stabilizer
4. Wing protectors
5. 10x6 Propeller
6. U/C and Wheels
7. Wing Struts and Wing Dowels
8. FPV Canopy
9. Tailwheel
10. Turnigy T-6A Transmitter
11. Foam Support for Optional Candy Dropper
12. Cabin Window Sticker
13. Wing Bands, "R" Clips and Bind Plug
14. Accessories, Screws, and Tools
15. Quick Start Guide
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10 911
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ASSEMBLY:
Step 1: U/C Assembly and Fitting.
1.Identify the parts shown above for the U/C
assembly.
2.Use a box spanner or similar to undo the lock
nuts on the axle.
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3.Slide a wheel on to one of the axles, ensure
the long spigot slides on first as shown.
4.Re-fit the lock nut using your spanner.
5.Tighten the nut so that there is no slop, but
the wheel spins freely on the axle.
6.Repeat the process for the other wheel.
DURAFLY PRIME TUNDRA 1200MM
READY TO FLY VERSION

Step 2: Attachment of the Horizontal Stabilizer
and Tailwheel.
7.Identify the pack of four 3x10mm machine
screws.
8.Using the 3x10mm screws, attach the U/C
assembly to the bottom of the fuselage. Please
note the direction of the cut out in the center.
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1. Identify the parts for the horizontal stabilizer. 2. Slide the 210mmx3mm carbon rod through the
hole in the rear of the fuselage.
3. Slide one half onto the carbon rod. 4. Repeat for the other side, ensure that the two
elevator joiners slide inside each other as you
do this.
2 x horizontal stabilizer halves, 1 x 210mmx3mm
carbon rod, 3 x 2.6x8mm self tapping screws
with molded on washers.

Step 3: Wing Strut Assembly.
5.Using two of the 2.3x8mm self tapping
screws, secure the two stabilizer halves to
the rear of the fuselage.
6.Using the third 2.3x8mm self tapping screw,
secure the joint between the two elevator
halves.
7. Clip the ballink on the pushrod onto the ball
that is attached to the control horn. If the
elevator requires adjustment to ensure it is
neutral, this will be covered later in the set-up
part of the manual.
8. Firmly push the tailwheel assembly into place
in the bottom of the rudder. Secure with two
2.3x10mm self tapping screws.
1. Identify the parts for the wing strut travel
retainers. Two off retainers and four off
2.6x6mm self tapping screws.
2. Mount the wing strut retainers using the four
2.6x6mm self tapping screws.
DURAFLY PRIME TUNDRA 1200MM
READY TO FLY VERSION
5

3. Next stage is to attach the wing struts to the
fuselage using the two M2x10mm screws and
lock nuts.
4. Ensure that you attach the wing struts so that
the large dished end faces the underneath of
the wing.
5. Also the struts are handed with one marked
with an "L". This strut goes on the left hand
side looking from the rear.
6. Attach the struts using the M2x10mm bolts
using the supplied hex key and a spanner or
thin nosed pliers.
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7. Ensure that the strut goes on the underneath
of the strut attachment and also the head of
the bolt is underneath with the nut on the top.
8. Above shows the struts in the stowed/ travel
position. Note: You can tighten the M2 nuts
and bolts as the struts will swivel on the
ballink.

1. For this step you need the wing and the two
plastic wing protectors. If you are using the
bandon wing system then you must use both
protectors. If using the bolt-on system then
you do not have to use them if you do not
want to.
2. If you have elected to use the band-on
method, then use a good quality glue such as
UHU Por to glue the protectors to the wing.
3.Plastic protectors glued into their correct
positions.
4. At this point you can stick the dummy window
to the center of the wing.
5. If using the band-on method then select this
wing retaining dowel set. The long one goes
to the front, and the short one to the rear.
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6. Slide the carbon rod with the band retainer on
one end through the fuselage. Use a small
drop of CA glue to secure the second plastic
band retainer into place.
Step 4: Wing Assembly.
DURAFLY PRIME TUNDRA 1200MM
READY TO FLY VERSION

Step 5: Setting up the Radio and Servos.
7.When using the band-on method it is best to
use 4 bands for safety. If you only received 3
bands with your Prime Tundra then any good
quality rubber bands can be used. If bolting
the wing on then use the supplied
M2.5x16mm machine screws.
8.When assembling the wing to fly, push the
end of the strut over the metal spigot sticking
out of the wing and retain with the supplied
"R" clip. Slide the "R" clips on from the
leading edge side of the fixing as shown.
Note: The basic construction of the Prime Tundra is complete, the next step is setting up the radio
and then fitting the propeller. To proceed to the next step you will need to remove the wings. Also for
the next steps the propeller must NOT be installed on the motor.
Note: A copy of the full manual for the radio is available at HobbyKing.com (Search: 9114000074-0),
or under the Prime Tundra Manuals/Files tab.
8
Main Transmitter Controls.

Auxiliary Switches on the top of the Transmitter.
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1.Remove the battery box cover on the rear of the transmitter and install 8 x "AA" batteries.
DURAFLY PRIME TUNDRA 1200MM
READY TO FLY VERSION

2. Before switching the transmitter on, ensure
that the throttle stick is fully down and throttle
trim is in the middle position as shown. Also
ensure the throttle disarming switch is
forwards (towards you), the gyro switch can
be in any position. Now switch the transmitter
on, and ensure you have a green light
showing on the battery indicator.
3. Now connect your 3S (11.1V) LiPo battery
into the speed controller XT60 connector.
Once the battery has been connected, do not
move the model until the gyro has initialized.
During the initialization process the ESC will
emit a series of beeps then will go silent. The
servo arms will move several times then
return to neutral, the gyro is now calibrated
and ready to use.
5. When the transmitter and receiver have
bound together and the gyro has initialized,
the gyro light will be doing one of the
following, depending on the position of the
switch. Position 1 with the switch fully up will
give a slow flashing light, this means the gyro
is off. With the switch in the middle, position
2, the light will flash quickly, meaning the
gyro is on. With the switch fully down,
position 3, the light will stay on, meaning the
gyro is in training mode.
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4. If your transmitter and receiver bind together
successfully you will obtain a solid red light
on the receiver as shown above and the
elevator and rudder servos will operate when
you move the sticks on the transmitter. If this
light flashes continuously then there is an
error, unplug the battery, turn off the
transmitter and try again. If the problem
persists you will need to consult the full radio
manual to do a re-bind of the Tx and Rx. You
will need the receiver binding plug which is
supplied with the Prime Tundra. At this point,
flick the motor arming switch to armed and
gently open the throttle to check that the
motor runs ok. This also activates the gyro,
the gyro will not operate unless the motor has
been armed. Once initially armed it can be
disarmed and the gyro will carry on working.
Note: If you do have problems binding or arming
the system, try moving the throttle trimmer
position down towards the bottom.
A copy of the full radio manual can be
found under the Prime Tundra Manuals/ Files tab.

6.The wing can now be re-attached to the fuselage using either the bands or the bolts. Before
you actually fit the wing back on you need to connect the two "Y" leads that are connected to
the wing servos. Connect these "Y" leads which should be labeled "Flap" and "Aileron" to the
corresponding extension leads that are plugged into the receiver. Ensure these connectors are
fully mated so that they cannot come apart, tuck the wires away safely, then attach the wings.
7.At this point we need to check that the flap servos and aileron servos are functioning correctly.
8.Switch everything on as previously instructed, once the system has initialized, check that the
flaps are working by using the 3 position flap switch on the transmitter. Next check that the
ailerons are working correctly when you move the aileron control stick.
Note: See the next page of this manual for the direction the controls should move when
control inputs are put in with the transmitter control sticks.
DURAFLY PRIME TUNDRA 1200MM
READY TO FLY VERSION
11

10.For the rudder or elevator, use the supplied
hex-key. Slacken the grub screw in the servo
connector, move the control surface to
neutral and re-tighten.
9.Your Prime Tundra has been set up at the factory, and all control surfaces should be at neutral.
With the system switched on and the gyro initialized the control surfaces should all be in their
neutral position. Ensure when you do this that the gyro is off, and all the trimmers are also in
their neutral position. If for any reason a control surface is not at neutral, you will need to do one
of the following.
11.For the flaps or ailerons, gently ease the ball
link off of the ball with a pair of long nosed
pliers. Be careful not to damage or break the
control horn.
12.Adjust the ball link as necessary by turning it
clockwise, or anti-clockwise
13.Just using your fingers, carefully, but firmly
snap the ball link back onto the ball. Use a
finger behind the control horn to support it as
you do this.
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Aileron Elevator Rudder

Aileron
(Roll)
Elevator
(Pitch)
Rudder
(Yaw)
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14.Now we need to check that the controls are working in the correct direction, see below.
Roll Left: Move the aileron stick to the left, the left aileron should go up.
Roll Right: Move the aileron stick to the right, the right aileron should go up.
Pitch Up: Move the elevator stick down, the elevator should go up.
Pitch Down: Move the elevator stick up, the elevator should go down.
Yaw Left: Move the rudder stick left, the rudder should move to the left.
Yaw Right: Move the rudder stick right, the rudder should move to the right.
DURAFLY PRIME TUNDRA 1200MM
READY TO FLY VERSION

15.Once again, the control throws were all set at the factory and should be as follows. The
lower figure is with the D/R (Dual Rates) switch on the top right of the transmitter pointing
towards the rear of the transmitter. With the switch the other way you will get full servo
throw and this should achieve the higher measurement. Do this check with the gyro in the
off position.
Mid flaps should measure around 15mm
from the fully up position.
Full flaps should measure around 30mm
from the fully up position.
Measure the flaps at the inboard end, the end nearest the fuselage.
Elevator
-1 mm
-1 mm
-1 mm
-1 mm
5- 0mm
1-2 mm
1-2 mm
Rudder
Aileron
Note: Measure the elevator throws at the end nearest the rudder.
Measure the rudder throws at the base of the rudder. The ailerons as they are a constant
chord so can be measured either end.
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DURAFLY PRIME TUNDRA 1200MM
READY TO FLY VERSION
6. Checking the gyro settings.
1. You now need to check that the gyro is functioning correctly.
2. Move the gyro switch down into the "Training Mode", this is the switch in the fully down
position. Now smartly roll the wings left and right, you should then see the ailerons moving in the
opposite direction to the rolling moment. Then smartly pitch the nose of the plane up and down,
you should then see the elevator servo moving the elevator in the opposite direction of the
pitching. Then move the nose sharply left and right, the rudder servo should then put the opposite
rudder command in. If you find it difficult to see which way a surface is moving, gently hold the
surface, then as you move the model, you should be able to feel the servo moving in the opposite
direction. When the gyro is in "Training Mode" this limits the amount of roll, pitch, and yaw you
can subject the model to. You can put a full control command in, and the model will only respond
up to a certain angle. Also this mode will self right the model if it starts to spiral out of control. Just
let go of the sticks, close the throttle, and the gyro will do the rest.
3. With the switch is in the middle position, "Gyro On" , perform the same actions as above, the
servos will still move but to a lesser degree. In this mode the gyro will still be assisting your flying
and helping smooth things out, but it does not limit the roll, pitch, and yaw angles, or will it self
right as quickly. In this mode you will be able to perform simple aerobatics when you are ready.
4. Now put the switch into the "Gyro Off" position, now when you perform this test, the servos
should not move at all. So in this mode you will get no gyro assist at all, this mode is only for
experienced flyers.
5. Once these checks are complete, leave the transmitter switched on and disconnect the flight
battery. Once the battery has been disconnected you can then turn off the transmitter. Never
have the flight battery plugged in and the transmitter switched off, this is dangerous.
6. So a quick recap on the switching on, switching off process. Always switch the transmitter on
first and check that the switches, trims and throttle stick are in their correct positions, only then
plug in the flight battery. Once you have finished testing or flying, disconnect the flight battery
first, and only then switch off the transmitter.
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1. Please ensure you fit the propeller the correct
way around. The picture above shows the
front of the propeller, so this of course should
face forwards, in the direction of flight.
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2. Remove the prop nut from the motor
shaft,slide the propeller onto the shaft and
replace the nut. Please make sure that the
molded on washer of the nut goes up against
the face of the propeller. Once finger
tightened, use a spanner to tighten the nut,
please do not overtighten otherwise you may
snap the shaft.
Step 7: Fitting the Propeller.
Your Prime Tundra is now ready
for checking the CG and its first flight.
Now you have finished setting up the radio, gyro, and servos, you can install the propeller
onto the motor shaft.
Note: Now the propeller has been fitted, please be extremely careful when switching the model
on, ensure that the transmitter is set correctly before switching on and connecting the battery.

DURAFLY PRIME TUNDRA 1200MM
READY TO FLY VERSION
Step 8: Battery Installation and Setting CG.
1. The recommended center of gravity (CG) for the Prime Tundra should be approximately 55-60mm from the
leading edge of the wing. This should be easily achieved if you use a 1300~1400mAh 3S LiPo battery
weighing between 110~125g. Ensure it is up against the foam ledge in the battery compartment as shown in
the picture below. Once the position of the battery is determine, secure it in place with the supplied hook and
loop tape.
2. This picture shows the battery position, as mentioned above, ensure the battery touches the ledge
at the rear of the battery compartment. With the battery in this position you should easily achieve the
correct CG. Also at this point, fix the Aerostar ESC (Electronic Speed Controller) to the side of the
fuselage with the supplied hook and loop tape.
CG 5 -60mm from leading edge.
CG
5-60mm
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9: Flying the Prime Tundra.
Once all the above has been done, you should be ready to fly the Prime Tundra for the first time,
then we highly recommend that you enlist the help of an experienced RC pilot by joining a local
model flying club. Here you should find a wealth of experience and knowledge from fellow
members to help you in getting into the air within a frame work and environment that is both safe
and organised. If the above option is not available to you then the guidelines provided here should
be considered essential reading before flying the PT1200. Also we highly recommend that you
read them before flying within the confines of a club environment too, so please read and follow
these steps very carefully. The Prime Tundra is super stable when the gyro is in training mode, but
flying an RC model for the very first time on your own does need to be done carefully and
methodically.
1. Choose a day when the wind is light, ideally 5mph (8kph) or less. Choose your flying area
carefully as mentioned in the "Safety Precautions" at the beginning of this manual. As a reminder,
choose an open area of reasonably short grass that is away from roads, railway lines, trees, power
lines, buildings, and most importantly people, especially crowds. Also, you should be at least 3
miles (5km) away from a full-size airport or airfield, and you should limit your height to 400ft and
below. Once you are satisfied that your flying area reaches the above criteria you are ready to fly.
2. Check the model over to make sure that no damage has happened on the trip to your flying site.
Check the linkages, wing fixings, tail, and U/C for security. Check that the propeller has not suffered
any damage, and is secure on the motor shaft.
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3. Now you are ready to switch the model on as recommended earlier in the manual. Switch on the
transmitter, check the positions of the trims and switches, then plug in the flight battery. The most
important one to remember is the motor disarming switch, also please remember to keep the model
still as the gyro goes through its initialization phase.
4. Once the gyro has initialized, move the control sticks to check the servos and that the control
surfaces are moving correctly and in the right sense. This means that with the aileron stick left, the
left aileron goes up, the elevator stick down, the elevator goes up, the rudder stick right, the rudder
moves right.
5. Now we need to do a range test of the radio system, we recommend that you do this before the
first flight every time you go out to fly, and not just before test-flying a new model. It is best to get a
helper to restrain the model on the ground whilst you perform this check just in case the motor
inadvertently starts up. It shouldn't with the motor switch in the disarm position, but it is always best
to play safe. Walk away with the transmitter for about 25-30 paces, then press the range test button
on the bottom left of the transmitter. With the button pressed (this reduces the power of the
transmitter) move the sticks about and check that the servos are functioning correctly. You can
always as well test the motor, but please make sure your helper who is holding the model is aware
and is clear of the propeller. If your radio system fails this test then do not fly. It may be that the
batteries in the transmitter are low, if so, install fresh batteries, then try again.