Great Planes RV-4 Park Flyer Kit - GPMA0010 - Manual (Page 4)

The RV-4 Park Flyer also flies well with the Great Planes
ElectriFly T-400 Ferrite Motor (GPMG0325). This motor
should be used with the Great Planes ElectriFly T-400 4.1:1
Gearbox (GPMG0226). The best prop is the APC 10 x 4.7
SloFlyer (APCQ5015). You will also need a 3mm prop
adapter (GPMQ4600).This combination gives less spirited,
but adequate performance, with much cooler motor
temperatures and longer motor lifespan.
The RV-4 Park Flyer flies in a very spirited manner with the
Great Planes ElectriFly S-280 Ferrite Motor (GPMG0305),
Great Planes ElectriFly S-280 5.0:1 Gearbox (GPMG0200)
and APC 10 x 4.7 SloFlyer Prop (APCQ5015). For this
combination you will also need a 3mm prop adapter
(GPMQ4600). With this motor you can also use the Great
Planes ElectriFly S-280 4.5:1 Gearbox (GPMG0201) or the
S-280 4.1:1 Gearbox (GPMG0202). An APC 9 x 6 SloFlyer
Prop (APCQ5013) would be a better prop with these
gearboxes. The Great Planes ElectriFly 8-cell 1050 mAh
NiMH Battery (GPMP0251) is not recommended with this
motor as the added run time could cause the motor to
overheat. This is a high power motor and adequate cooling
is important. Be sure to follow the cooling instructions on
page 31, steps 11 & 12 of this manual. Allow 10 – 15 minutes
of cooling time between flights.
An even more powerful motor for the RV-4 Park Flyer is the
Great Planes ElectriFly S-370 Ferrite Motor (GPMG0310).
This motor is nearly the same physical size as a 280-size
motor and can be used with the same components
recommended above for the S-280 motor. A 20-amp ESC
should be used with this motor and adequate cooling is
critical. It is best to limit this motor to a 7-cell 650 mAh
battery. With an 8-cell 1050 mAh battery, motor
temperatures can easily reach 240 degrees, which would
greatly reduce the lifespan of the motor. Be sure to follow
the cooling instructions on page 31, steps 11 & 12 of this
manual. Allow 20 minutes of cooling time between flights.
The RV-4 Park Flyer can be powered with brushless motors
as well. While these motors and their controllers are
expensive, they give outstanding performance with longer
flight times and cooler motor temperatures than the above
ferrite motors.
There are three kinds of battery packs used for electric R/C
models: nickel-metal hydride (NiMH), nickel-cadmium
(NiCd, pronounced ny-cad) and Lithium Polymer (Li-Po).
NiMH and Li-Po batteries are recommended for the RV-4
Park Flyer because they provide from two to six times the
capacity of a NiCd battery of the same size and weight.
However, it should be noted that NiMH and Li-Po cannot be
charged as fast as NiCds. Li-Po batteries also require a
special charger.
For NiMH and NiCd batteries, each individual cell that
makes up a battery is 1.2 volts. For a Li-Po battery each cell
is 3.7 volts. Batteries are also rated by their capacity in mAh
(milli-Amp-hours), or how much energy they store. A 650
mAh battery can supply 1
Ampere for .65 hours (about 39
minutes). At a typical average park flyer power requirement
of 5 Amps, a 650 mAh battery will last about
7-1/2 minutes.
These are the battery packs recommended for the RV-4
Park Flyer:
GPMP0071 – 7-cell, 650 mAh NiMH pack
GPMP0072 –8-cell, 650 mAh NiMH pack
GPMP0250 –7-cell, 1050 mAh NiMH pack
GPMP0251 – 8-cell, 1050 mAh NiMH pack (for 400
size motor only)
KKMP9100 – Kokam 2-cell, 340 mAh Li-Po pack
KKMP7100 – Kokam 2-cell, 1500 mAh Li-Po pack
KKMP8100 – Kokam 3-cell, 1500 mAh Li-Po pack (for
400 size motor only)
Caution: Use extreme caution when using Li-Po batteries
with the S-280 and S-370 motors. Due to the very long run
times these batteries can provide, overheating of these
motors will occur, resulting in VERY short motor life-spans.
The following performance packages are recommended for
the RV-4 Park Flyer. You may wish to experiment with other
combinations to obtain the performance level you find
most enjoyable.
Performance Options
At the time this manual was prepared, Lithium Polymer
batteries were becoming popular but were not widely
used. This model is ideally suited for these Li-Po
batteries. In particular, a two or three cell (7.4 or 11.1
volt), 1200 mAh or 1500 mAh pack would be ideal for this
model – providing much longer flight times and
considerably lighter weight of the ready to fly model. The
three cell pack will require careful power management as
it could easily damage the S-280 or S-370 motors due to
the higher than recommended voltage and capacity of
the battery. Full power should be used only for a very
limited time, with the majority of the flight at a reduced
power setting. In addition, the longer run times could
cause severe overheating of these motors. Therefore,
only a two cell Li-Po battery is recommended for use with
these motors.
Lithium Polymer batteries require a special charger. DO
NOT use a charger designed for other types of batteries.
Battery Recommendations
4