GRAUPNER GmbH & Co. KG D-73230 KIRCHHEIM/TECK GERMANY
No liability for printing errors. We reserve the right to introduce modifications.
10/2006
5
1932
OS MAX 120 AX
20.0
2703.33
38.25 cm
2703
1318.38.25
Radio control system
For this model you require at least a four-channel RC system with six servos. The transmitter should also
feature a servo reverse facility.
We particularly recommend: mx-16 to mc-24 computer systems. The model is designed for standard-size servos. We
recommend the following receiver battery: SAFT 4NH-3000 CS, Order No. 2566, which should be properly maintained
before and after each flying session. Please note that the pack needs to be cycled (charged and discharged) several
times before it reaches full rated capacity.
For connecting the two aileron servos to the receiver you will need a folding ferrite ring, Order No. 98516, plus two
extension leads, Order No. 3935.32.
Each aileron servo lead will need to be extended using an extension lead, Order No. 3935.18, while the elevator
servos will each require an extension lead, Order No. 3935.11.
Shock-absorbing material for protecting the receiver and battery is supplied in the kit.
Adhesives
Fast-setting epoxy resin, e.g. UHU plus schnellfest, Order No. 962
Slow-setting epoxy resin, e.g. UHU plus endfest 300, Order No. 950
White glue, e.g. UHU coll, Order No. 958.60
UHU hart cellulose cement, e.g. Order No. 534
Cyano-acrylate glue (“cyano”), e.g. Order No. 5821
Thread-lock fluid, e.g. Order No. 952
Accessories for flying the model
(not included)
Synthetic oil based fuel, to suit motor
Fuel filter, e.g. Order No. 1650.1
Fuel tubing, e.g. Order No. 1643
Manual fuel pump, e.g. Order No. 1610 or 6870
Glowplug energizer battery and glowplug clip, e.g. Order No. 3248
Electric starter, e.g. Order No. 1628
Starter battery, e.g. Order No. 2592
Tools required
(not included)
Various (cross-point) screwdrivers, pointed-nose pliers, flat-nose pliers, side-cutters, balsa knife or razor blade, set of
twist drills, universal glowplug spanner, Z-bend pliers, Order No. 5732, standard soldering iron, pencil or felt-tip pen,
fine-point soldering iron.
Assembling the YAK 54
Don’t start building the model until you have read right through the building instructions and are familiar with all the
model’s components. If you are not satisfied with any part, inform your supplier before you start work on the model.
Use your fingertips to locate the slots in the fuselage for the tailplane and fin, the openings in the wing panels for the
servo mounts and servo cable exits, and the holes in the fuselage for the undercarriage retaining screws. Use the tip
of a hot soldering iron to melt away the film over these areas.
Press the rubber grommets and metal tubular spaces into the servo mounting lugs, as shown in the photo. The servos
are installed by placing them in their mounts, drilling 1.5 mm Ø pilot-holes through the mounting lugs, and screwing
them in place.
Connect the appropriate extension leads to the two aileron servos. Secure the connections with drops of cyano or
heat-shrink sleeves to prevent them shaking loose.
Place the aileron servos in the wing panels as shown in the pictures; drill 1.5 mm Ø pilot-holes, and fit the retaining
screws to secure them.
Allow the servo leads to fall through the openings in the wing ribs until they emerge at the root ribs.
Position the horns on the ailerons in such a way that the pushrods are exactly at right-angles to the servo output arms.
Screw the horns in place as shown in the photos.
Once the horns have been screwed in place, snip off excess screw length using side-cutters, and file them back flush
with the spreader plate.
Locate the aileron pushrods in the hardware pack (length approx. 160 mm), screw clevises onto both ends of each
one, and apply a drop of UHU thread-lock fluid to prevent them working loose. Connect the clevises to the aileron
servo output arms and the aileron horns.
Adjust the pushrod lengths until the ailerons are exactly at neutral when the servos are at their centre position. Allow