GRAUPNER GmbH & Co. KG D-73230 KIRCHHEIM/TECK GERMANY
No liability for printing errors. We reserve the right to introduce modifications.
10/2006
7
the tank under water, seal two tubes and blow into the third: any bubbles indicate a leak which must be corrected.
Push pieces of fuel tubing onto the tubes where they exit the fuel stopper.
Mark the fuel lines using a felt-tip pen to indicate which is the fuel feed, the overflow and the filler.
Fit the fueltank into the fuselage from the rear, threading the three fuel tubes through the hole in the nose bulkhead.
At this point the fuselage can be set on its undercarriage in order to install the glow motor. Note that the model is
designed for a ‘side-winder’ style installation, i.e. the motor’s cylinder should lie horizontal on the right-hand side. Fix
the two-part motor mount to the nose bulkhead using the retaining screws supplied, and secure the screws with a
drop of UHU thread-lock fluid to prevent them working loose. Place the motor on the motor mount and position it so
that the distance between the nose bulkhead and the propeller driver is about 125 mm.
Connect the throttle pushrod to the carburettor arm, then slip the pushrod through the guide tube and through the
cross-hole in the swivel pushrod connector fitted to the throttle servo. Set the carburettor barrel to the ‘half-open’
position, and clamp the grubscrew in the pushrod connector with the servo also at centre. Tighten the nut on the
swivel connector to the point where it swivels smoothly on the servo output arm, but without perceptible slop.
Cut and file out the holes in the cowl to clear the cylinder head, silencer, needle valve, etc. The position and size of
the openings varies according to the motor you have installed.
Assembling the YAK 54
To connect the aileron servos to the receiver we recommend using two 100 mm long extension leads. Connect the
extension leads permanently to the appropriate receiver output sockets (2 and 5).
Connect the aileron servos to the extension leads. Slip the wing joiner tube through the fuselage, slide the wing
panels onto the tube, and fit the four plastic screws through the fuselage sides and into the wing roots to hold them
against the fuselage. Don’t over-tighten the screws; tighten them just to the point where the wings rest snugly against
the fuselage, and cannot move.
Balancing the YAK 54
With the fueltank empty, support the model under both wing roots at a point about 120 mm aft of the wing leading
edge. If the CG position is correct the model will hang level, with the nose inclined slightly down. If necessary, glue
lead ballast inside the nose or tail to obtain the correct balance All the control surfaces must be exactly at centre when
the transmitter sticks and trims are in the neutral position. Check this before you attempt to fly the model for the first
time.
Control surface travels for normal flying
Ailerons
35 mm up, 35 mm down
Elevators
85 mm up, 85 mm down
Rudder
85 mm right, 85 mm left
We recommend setting the following exponential values for the control surfaces:
Ailerons
30%
Elevators
40%
Rudder
20%
Important:
When installing and adjusting the various linkages you should ensure that they move freely, without binding, are able
to move to their full extent - including trim travel - and are not obstructed mechanically at any point.
When you move the rudder stick to the right, the rudder should also deflect to the right (left stick: left rudder). Pull the
elevator stick back towards you, and the elevators must both deflect up (stick forward: elevators down).
If you move the aileron stick to the right, the right aileron should rise, the left aileron fall. When you move the throttle
stick forward, the motor should run to the full-throttle position, i.e. the carburettor barrel should be fully open.
And now all that remains is to wish you many hours of pleasure flying your YAK 54.
Yours - the
Graupner
team