FUSELAGE
Composite sandwich with all bulkheads installed from our factory. Plan your instalation very carefully,as every item adds up to a higher flying weight. We do provide some photos for easier understanding how things are done.

IMPORTANT: any holes made in the fuselage,not done by our factory, MUST be streghten with carbon fiber tow all around. This is necessary to maintain overall stregth of the
fuselage!!!

 

Rudder servos tray
One provided is to be used with 4 servos. However if using only 3 servos , last opening remains empty or can be cut off. In this case we do recommend to use at least 3 x 30kg servos (i.e. JR 8711,etc.).
Position rudder servo tray right in front of half moon bulkhead , located in the middle of canopy. This will help to keep evrything close to CG.
Tray comes with two half moon shape holders,which fit into botttom half of the fuselage.. Use 30 min. epoxy.
See pictures ..

Exhaust
If using reg.mufflers, install them and cut out openings in the engine cowl. If tuned exhaust will be used, under no circumstances cut into landing gear plate!! This will make landing area very weak and might break on landing! Tuned exhaust holders are optional,( plese reffer to our ordering form), but ones that come with your set can also be used.
Use X-acto blade to make cut outs in the fuselage.
See pictures ..

Fuel tank
To be mounted on top of tuned exhaust plate. Use Tie wraps or Velcro to secure it in place. Cut slots in supplied ply wood floor accordingly. There is enough room for two tanks,if you want to use a smoke.
See pictures ..

Firewall
Already installed for you.

Engine dome
Made from carbon fiber, predrilled mounting holes and marked center lines for easy engine instalation. Horizontal and vertical lines are showing centre of the engine.
Any modification to dome is not allowed.as this will make it less strong. Only area that can be cut out is on the bottom, which will allow tuned pipes to be fitted inside the fuselage.
Fuel lines going through the front must not have any sharp edges, as they will cut into fuel line right away!!
See pictures ..

Engine cowl
Already fitted in, no modification needed, just use 10 screws all around to secure it to fuselage.

Tail wheel
Very simple instalation, using 3 screws, pictures are showing different ways of steering control.
See pictures ..

CANOPY
There is a plywood glued into a front area of canopy opening, from inside the fuselage.
Place the canopy onto fuselage,secure it with tape.Then,through the opening in the firewall and using a ¼“ bit,drill right through into canopy frame.This will assure a proper alligment when instaling the front pin.
After securing front pin, drill one hole on each side of fuselage right where the plywood plates are glued into canopy frame. Press in blind nuts from inside and secure with CA glue.
See pictures ..

LANDING GEAR
Using 4 x M5 x 30mm for attachment to the fuselage.
First press 4 blind nuts into 4 round plywood circles and then glue them onto landing gear plate from inside the fuselage using 30 min epoxy.
For attaching wheel pants use your favored method or see pictures.

RUDDER
Control horns are supplied, location is shown on the drawing.
However,if you decide to use your own control horns,it is possible and this is the reason why no slots are precut.
There is a balsa block glued inside in all control surfaces for this purpose. Make sure your control horns are glued in properly!!
 

WING
Incidence is set up from the factory.

Servos installation – 6 pcs of plywood plates, 12 pcs of plywood blocks, 26pcs screws for wood, 12 pcs of CNC f/g control horns
UNDER NO CIRCUMSTANCES ONLY ONE MIDDLE AILERON SERVO SHOULD BE USED ON THIS AIRPLANE!!!!!!!!!!!!!!
IF USING ONLY TWO SERVOS, USE INSIDE AND OUTSIDE SERVO BAYS. MIDDLE ONE WILL REMAIN EMPTY!!!!


The openings for servos are already prepared. Sand the plywood plates so they fit into those openings. Measure up the servos positions, so that the output shaft of the servo is in the middle of plywood plate. Glue the plywood blocks onto the bottom side of the plate and secure them with one wood screw from outside. Then in the outer corners of the plate drill the holes for four screws.
There are marked spots on the ailerons for cutting slots for CNC f/g horns, always 1 pair for one servo. You can also use other control horn system. In each marked spot there is a balsa block of approx. 4x4 cm
(1 ½” x 1 ½”).

Very important is the way of sliding wings together..
The wing is a fiberglass sandwich, therefore you should hold it by it’s leading egde and wing spar during this procedure. DO NOT EVER PUSH and/or hit on the wing tips !!! Perform the final matching of the wings to fuselage with both-hands pulling on the wing spar from inside of the fuselage. The removal should be done in the same way.

ASSEMBLING and SECURING the wings
Securing wings to the fuselage is done by using 4 x M6 screws from inside the fuselage into a wing root.
Front holes should be drilled precisely, back ones can have a larger opening.
Wings should be set up at 0 degrees, but it can be fine tuned later after few flights.
For this reason we supply 2 round 25mm diameter f/g washers. Put a double sided tape on them and place them into fuselage. This set up is fine for few flights and gives you chance to adjust wing incidence. When satisfied, just drop some CA glue around the edges of f/g washers. And you are done!!

!Before flying, make sure all the screws are tightened all the way in!

ELEVATOR
Installation of servos and control horns is done same way as with the wings.
It’s recommended to drill holes from the bottom of stab, about 10mm (3/8”) from the end of tube and use 3mm (6-32) screw to secure elevator from coming apart. We have installed small piece of balsa wood inside to prevent crushing elevator skin. It can be seen through servo bay opening.
Warning!: Never drill these holes right onto half rib, that supports elevator tube at the end!

PAINT AND DECALS
You can spray any kind of color and use any stickers you wish on this model. We do not recommend to use any iron on materials, because that could damage airplane strength and finish.
Choose your colors wisely. We also do not recommend spraying the model with dark colors (black etc.) because the model is all-fiberglass. By the way – this rule is followed with full size planes as well. Due to an intensive sunshine, dark colors will get 3 times hotter and that could have negative effect on some parts of the plane. This also applies for transport and storage of this plane.
For this reason a white airplane cover should be used in hot weather!

TRANSPORT, STORING AND CARRYING AIRPLANE AROUND
Store and/or transport the model always well protected against “hangar rush”. The fuselage can be left on it’s wheels, wings should have covers on during storage. Storage place should be dry and have room temperature.
On flying field, always pull airplane around by holding onto a tail wheel or a prop.
Keep in mind that taking care of the airplane will extend it’s life!!

BASIC SAFETY RULES AT THE MODEL OPERATION
- MAKE A PRE-FLIGHT PREPARATION BEFORE EACH FLIGHT e.g.
CHECK ALL PARTS OF THE MODEL.
- Pay special attention if children are present. They should not be around, specially if the engine is running.
- Flying should be done only at designated flying fields.
- Do not forget to turn off radio equipment and ignition right after each flight.
After finishing the flights, e.g. before the transport and storing the airplane, pump all the remaining gasoline out.

KRILL.B.P,s r.o. is not responsible for any damages caused by using this model airplane. Model airplane owner is using it on his own responsibility.

 

RECOMMENDED THROWS:

Elevator

High rates

Low rates

60-70mm at the root

40% of high rates

Ailerons

High rates

Low rates

50mm at the root

 

30mm

Rudder

High rates

Low rates

as much as you can get

60% from high rates

Aileron differential  

100%

Mix :

Rudder with Elevator
right Rudder

left Rudder

+12% up elevator

-15% down elevator

We would appreciate all your comments, notes and pieces of knowledge, gained with your Yak 55 M model assembly. We hope that you will share photographs of your finished model with us. Provided you will have any question, please, contact to our agents, and/or directly us at service@krill-model.com

 


 

www.krill-model.com