Great Planes PT-40 MkII Kit - GPMA0118 - Manual (Page 4)

❏
4-Channel radio with 3 or 4 servos; see Wing
Configuration Section.
❏
Engine; see Engine Selection
❏
Spare Glow Plugs (O.S. #8 for 2-stroke engines,
OSMG2691), (O.S. #F for 4-stroke engines,
OSMG2692)
❏
Propeller (Top Flite ® Power Point ® ); Refer to your
engine's instructions for proper size
❏
Top Flite Super MonoKote ® Covering (Approximately
2 rolls); see Covering
❏
Medium Fuel Tubing (GPMQ4131, 3')
❏
1/4" Latex Foam Rubber Padding (HCAQ1000)
❏
1/16" Foam Wing Seating Tape (GPMQ4422)
❏
4 or 6 oz. Fuel Tank (4 oz. GPMQ4101),
(6 oz. GPMQ4102)
❏
(1) 2" Nose Wheel (GPMQ4221)
❏
(2) 2-1/4" Main Wheels (GPMQ4222)
❏
(6) 5/32" Wheel Collars (GPMQ4306, pkg. of 4)
❏
Fuelproof Paint; see Finishing
❏
2" Spinner (GPMQ4510 - white)
❏
#64 Rubber Bands - optional (HCAQ2020);
see Wing Configuration
Accessories Required to Complete
Your PT-20
PREPARATIONS
You also have the option of securing the wing to the
fuselage either with nylon bolts or rubber bands. The
hardware is furnished in the kit for both options. If this is
your first kit we recommend that you go with the rubber
band method. Rubber bands offer two advantages
over bolts: First, the model is easier to build. Second
(this is the important one), rubber bands allow the wing to
shift if your wing tip contacts the ground (or an obstacle)
upon takeoff or landing. Bolts are less forgiving in this
respect, and even a minor whack can cause enough
damage to send your PT back to the shop for repairs.
Wing Configuration
You have a choice in the type of wing to build – the
trainer (“A-wing”) or the sport (“B-wing”). The A-wing
has more dihedral than the B-wing and will allow your PT
to fly just great as a 3-channel model without functioning
ailerons. We show you how to build the ailerons but “lock”
them down. You can always hook them up later. Building
the A-wing without functioning ailerons saves you a little
money (most four channel systems are sold with three
servos) and building time. If the PT is your first R/C
model we strongly (that's strongly) recommend that you
build the A-wing with more dihedral. If you build the sport
wing you will lose the full benefit of the self-recovery
features of the PT – features that will help you solo faster
and safer.
With the lower dihedral angle of the B-wing you may still
fly your PT without functioning ailerons, but it performs
best with ailerons – this configuration will suit
intermediate and sport flyers.
Engine Selection
There are many engines that will work well in your PT.
For the PT-20 we recommend a 2-stroke sport engine
such as the O.S.
® .20 or .25 FP, or the .25 FX (high
performance). Generally, most beginners start out with a
2-stroke engine but for some of those who are a little
more ambitious and “must have” the sound of a
4-stroke, the O.S. .26 FS is a good choice.
For the PT-40 we recommend a 2-stroke sport engine
such as the O.S. .35 or .40 FP, or the .40 or .46 FX (high
performance). If you choose the 4-stroke option, the O.S.
.40 or .48 FS is a good choice. Super Tigre
™ also offers
the G-40 and G-45 sport engines.
Your dealer will be able to help decide which engine is
the best choice but basically, the O.S. FP series has
proven to be the highest quality yet most economical
choice. The O.S. FX series and the Super Tigre G series
are higher performance engines and might be a little
overkill for a trainer but would be good powerplants for
sport models you may build in the future.
4-Stroke engines are neat because they provide a
realistic sound (realism is generally not a requirement for
a trainer, mind you), are generally quieter than a
2-stroke and appeal to those who are a little more
technically or mechanically minded. 4-Stroke engines do
cost more and require a little more care than a 2-stroke. If
you use a 4-stroke in your PT you will have to relocate
the throttle pushrod exit location on your firewall so
plan ahead.
DECISIONS YOU MUST MAKE
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