Great Planes RimFire 50 User Manual

50MM BRUSHLESS
OUTRUNNER MOTOR

Congratulations, you have just purchased one of the RimFire 50mm
power system components. All the components are sold separately to
allow you to customize your power system to your airplane. The
components needed to assemble your complete RimFire 50mm
power system are: RimFire 50mm motor, propeller, propeller adapter
and brushless speed control. This instruction sheet explains how to
determine what you will need and how to assemble each component.

MOTOR

1

55mm OR 65mm

50mm

19mm

24mm

8mm

Please note that the kV of a motor does not change with voltage, but if a
higher voltage is applied to the motor, it will try to spin the same propeller
at a higher rpm. This will cause the motor to draw more current and pos­sibly exceed the maximum rated current of the motor. So, if a battery with
lower voltage is replaced with one with a higher voltage, it is recom­mended that a smaller propeller be used to keep the current in check. If a
higher voltage battery is replaced by a lower voltage battery, the size of the
propeller can be increased to keep the motor at its rated current.

Another possibility to fine tune the power system’s performance is to use
another motor with higher kV to increase the current or a lower kV to lower
the current.

ELECTRONIC SPEED CONTROL (ESC)

2

An ESC is basically the device that controls your motor through your radio
system. Never run any RimFire motors with a brushed ESC. It will not
work and you may damage both the motor and the ESC. Always use a
brushless ESC. ElectriFly offers the Silver Series SS-60 and SS-80
Brushless ESCs (GPMM1850 and GPMM1860) that work well with the
RimFire 50mm motors.

The SS-60 ESC comes with 4mm female bullet connectors that plug directly
into the 4mm male connectors installed on the RimFire 50mm motors, so
no soldering is required. The SS-80 comes with 6mm female bullet
connectors and requires an adapter (GPMM3119). Also, these ESCs come
with a Deans
that are found on most batteries that it will use.

3

®

Ultra Plug® battery connector that matches the connectors

BRUSHLESS LARGE MOTOR MOUNT

LIPO BATTERIES

6

Number of Cells

Batteries can be connected in series (S) or in parallel (P). A LiPo
battery is advertised by voltage and capacity where each cell carries

3.7 volts. A 4S LiPo battery would be 4x 3.7V or 14.8V. The capacity
is listed in milli-amp hours or mAh, so a 5300mAh battery can
discharge a maximum of 5300 milliamp-hours or 5.3 amp-hours.
Please also be aware of the battery’s discharge current delivery
capability, or C-rating. A 25C, 5300mAh battery will deliver 132.5A of
current regardless of voltage.

For the most up-to-date list of LiPo batteries, check out the ElectriFly
web site at: www.electrifly.com

Stock # Voltage Capacity Weight # of Cells Discharge

GPMP0519 7.4V 2200mAh 4.4oz (125g) 2 25C
GPMP0520 11.1V 2200mAh 6.3oz (179g) 3 25C
GPMP0521 14.8V 2200mAh 8.2oz (233g) 4 25C
GPMP0540 7.4V 3350mAh 6.6oz (188g) 2 25C
GPMP0541 11.1V 3350mAh 9.7oz (275g) 3 25C
GPMP0542 14.8V 3350mAh 12.2oz (347g) 4 25C
GPMP0543 18.5V 3350mAh 15.3oz (435g) 5 25C
GPMP0560 7.4V 5300mAh 10.3oz (291g) 2 25C
GPMP0561 11.1V 5300mAh 15.4oz (436g) 3 25C
GPMP0562 14.8V 5300mAh 19.6oz (555g) 4 25C
GPMP0563 18.5V 5300mAh 24.6oz (698g) 5 25C

REPLACEMENT PARTS

7

24mm

3mm
Mounting
Screw

The RimFire motors are labeled to provide the most information at a
glance. For example: the RimFire .60 (50-55-650) is 50mm in
diameter, 55mm long and has a kV (rpm-per-volt) of 650.

RimFire .60 (50-55-650) (GPMG4745)

Motor Output Shaft Diameter and Length: 8x19mm [0.32"x0.76"]
Weight: 298g [10.5oz]
Input Voltage: 18.5 – 22.2V
Max Surge Current: 85A
Max Surge Power: 2200W

RimFire .80 (50-55-500) (GPMG4740)

Motor Output Shaft Diameter and Length: 8x19mm [0.32"x0.76"]
Weight: 298g [10.5oz]
Input Voltage: 18.5 – 22.2V
Max Surge Current: 65A
Max Surge Power: 2200W

RimFire 1.20 (50-55-450) (GPMG4770)

Motor Output Shaft Diameter and Length: 8x19mm [0.32"x0.76"]
Weight: 400g [14.1oz]
Input Voltage: 18.5 – 22.2V
Max Surge Current: 85A
Max Surge Power: 2300W

1. Front Plate (1) 5. #6 Flat Washer (8)

2. Back Plate (1) 6. Motor Bracket (1, not used)

3. Screw Plate (4) 7. 6-32 Lock Nut (2, not used)

4. 6-32x1/2” SHC Screw (8)

The ElectriFly Brushless Large Motor Mount combines ease of installation
with the adjustability to fit most motor applications. The Large Motor
Mount is designed to fit the bolt pattern of the Great Planes
.60-1.20 Nylon Engine Mount. This easily allows the conversion of a glow
powered plane to electric powered.

PROPELLERS

4

®

.40-.70 and

GPMM3114 4mm Gold Plated Bullet Connectors - Male (3)

GPMM3115 4mm Gold Plated Bullet Connectors - Female (3)

GPMQ4909 RimFire Prop Adapter for 50mm Motors

GPMG1205 RimFire Backplate Motor Mount for 50-63mm Motors

GPMG1436 C-clip (10) for 8mm RimFire Motor Shafts

GPMG1458 Bearings (3) for RimFire 50-xx-xx Motors

GPMG1418 Replacement Shaft Kit for RimFire 50-55-xx Motors

Understanding Motors

kV (rpm/volt): This is a number that gets thrown around quite a bit
when talking electrics and it is important to know what it is. kV is the
number of rpm a motor will spin per each volt applied (rpm/volt)
under no load.

This means that a motor with a kV of 1000 when connected to a 12V
battery will try to spin at 12,000rpm (1000x12) under no load.
Likewise a 3500kV motor will try to spin at 42,000rpm (3500x12)
under no load.

When a propeller is attached to the motor, the motor will try to spin
the prop at the rated kV. Depending on the diameter and pitch of the
propeller (the larger the diameter or higher the pitch, the harder it is
to spin), the motor’s current draw can be increased or decreased.
There are meters available from your hobby dealer that measure
current and voltage.

Because every motor has a maximum current it can take based on its
design and cooling ability, the maximum size of propeller that can be
used with each motor can be determined. If the propeller is too large,
the motor will spin at a much lower rpm than its rated kV, causing it
to draw a lot of current and overheat. If the propeller/fan is too small,
it will require little effort (current) to turn the prop at the rated kV.

Ideally the motor should be matched with a propeller that causes the
motor to draw 80-100% of its rated maximum constant current. Once
a power system is set up, it can be fine-tuned by adjusting the propeller
size and measuring the amount of current the motor is drawing.

There is a wide selection of propellers available for electric use. The RimFire
50mm motors use high performance electric props such as the APC
E-series props. The larger the propeller used, the more current your motor
will draw. The smaller the propeller, the less current the motor will draw.

Shown are a few of the recommended electric props. Due to the large
range of propellers and the constant addition of new sizes, visit our web
sites at www.electrifly.com and www.greatplanes.com for the most
up-to-date listing of electric type props.

APCQ1055 11x5.5 Electric
APCQ4129 11x8 Electric
APCQ4130 12X6 Electric
APCQ4133 12x8 Electric
APCQ3065 13x6.5 Electric
APCQ3080 13x8 Electric

PROPELLER ADAPTERS

5

The RimFire 50mm motor comes with a prop adapter that mounts directly
to the motor case. If the RimFire 50mm motor needs to be mounted so
that the prop is mounted on the motor shaft, the motor requires an 8mm
prop adapter collet type (GPMQ4971) or set screw type (GPMQ4945).

GPMQ4971 8mm Collet Type

APCQ4145 14x7 Electric
APCQ4013 15x8 Electric
APCQ1606 16x6 Glow
APCQ4018 17x8 Electric
APCQ4024 19x8 Electric

GPMQ4945 8mm Set Screw Type

DETERMINE WHAT YOU NEED TO BUILD YOUR POWER SYSTEM

8

Now that you have one component for your power system, there
are several different ways to select the rest. In time, experience will
help you to determine what works best for you, but an easy way to
determine what you need now is the following.

Procedure #1: If you know the size of the propeller you want to turn
and the rpm, then:

1. Find the combination that delivers the closest performance to what

❏

you want (refer to the ElectriFly web site for typical combinations),
or refer to the airplane manufacturer’s recommendations.

2. Note the recommended battery voltage.

❏

3. Determine the battery capacity needed based on the current draw

❏

of your system and your desired fl ight time.

4. Determine the ESC you need based on the system current draw.

❏

See the ESC section.

Procedure #2: If you know the approximate weight of your airplane,
including the motor and battery, and the performance you want from
it, answer the questions below to determine the correct power system
for your plane. You may need to make more than one calculation using
different motors and battery combinations. See the battery section for
some of the battery weights for the suggested batteries.

1. Perform the following calculation to determine the wattage required:

❏

• If you expect trainer-like performance, then multiply

75 × Airplane Weight (lbs)

• If you expect aerobatic or high speed-like performance, then

multiply 100 × Airplane Weight (lbs)

• If you expect 3D or extreme performance, multiply

150 × Airplane Weight (lbs)

2. The number you get is the minimum wattage you will need for

❏

your plane to perform as you wish. Watts = current (A) × voltage
(V). Using suggested power system combinations as reference,
determine what combination gives you the performance you
want based on wattage and maximum propeller size that will fi t
on the plane.

3. Note the recommended battery voltage.

❏

4. Determine the battery capacity needed based on the current draw

❏

of your system and your desired fl ight time.

5. Determine the ESC you need based on the system current draw.

❏

In addition to these two procedures, you can also visit the Great
Planes ElectriFly web site for descriptions of the power systems
recommended for our line of electric and glow airplanes as well as
more detailed explanation on the subject.

Recommended Setups:

RimFire .60: 6S Battery, 12x6 Electric Prop
RimFire .80: 6S Battery, 15x8 Electric Prop
RimFire 1.20: 6S Battery, 17x8 Electric Prop

ASSEMBLE YOUR POWER SYSTEM

9

Once the required RimFire motor has been determined, it needs to be
installed on the plane. To determine the best mounting system, the
distance from the firewall to the front of the prop adapter first needs to
be determined.

It can be mounted directly
to the firewall using the
RimFire aluminum mounting
plate (included with the
motor) which replaces the
Great Planes® .60-1.20
nylon engine mount; or, an
ElectriFly 36mm Motor
Mount (GPMG1260) which
replaces the Great Planes
.40-.70 and .60-1.20 nylon
engine mounts.

Motor Mount Template

Check the airplane instruction
manual for the correct distance.
These pictures show the distances
from the firewall to the front of
the prop adapter using the
different mounting systems.

If you are replacing a glow engine
with an electric motor system,
remove the nylon engine mount
and replace it with the Large
Motor Mount or RimFire mounting
plate, using the same bolts to
attach it to the firewall. If the
firewall has not been drilled for an
engine mount and blind nuts, use
the mounting template on the
header card to locate the mounting
holes. Drill the four mounting
holes and install 8-32 blind nuts
from the back of the firewall.

MOUNTING PLATE INSTALLATION

If attaching the motor to the firewall using the adjustable motor mount,
skip to the Large Motor Mount Installation.

Note: Apply a drop of Threadlocker (GPMR6060) to all bolts and screws
used to install the motor on the plane.

Attach the backplate to the motor using four
3x8mm flat head machine screws.

Attach the Backplate of the motor mount
to the firewall using four 8-32 machine
screws and four #8 flat washers. Apply a
drop of Great Planes Threadlocker to the
screws before installing them. Mount the
aluminum prop adapter to the motor case
using four 3x7mm SHC screws. Use a
drop of Threadlocker to the threads of
each bolt.

LARGE MOTOR MOUNT INSTALLATION

Note: Apply a drop of Threadlocker (GPMR6060) to all bolts and screws
used to install the motor on the plane.

Attach the backplate of the motor
mount to the firewall using four
8-32 machine screws and four #8
flat washers.

Remove the c-clip from the
motor shaft. Mount the
RimFire motor to the motor
mount front plate (front or
back) using four 3mm
machine screws.

Slide the 8mm spacer,
included with the motor, and
the brass collar on the motor
shaft. Tighten the set screw
in the brass collar, making
sure the collar does not rub
on the motor mount.

Install the collet or set screw prop adapter on the motor shaft or the
aluminum prop adapter on the motor case. Great Planes carries a full line
of collet type prop adapters to fit shafts from 1.5mm to 8mm in diameter.
The RimFire 50mm motors use the 8mm prop adapter (GPMQ4971 Collet

Type or GPMQ4945 Set Screw Type).

COLLET TYPE PROP ADAPTER INSTALLATION

Slide the prop shaft
over the output shaft
of the gear drive or
motor. Next slide the
prop shaft retainer
over the prop shaft.
Note that the hole
through the retainer is
tapered. Make sure
that the side with the
larger diameter hole is installed first. Install the spinner backplate (if
used, not included), the prop, prop washer and then the prop nut.
Tighten the prop nut against the prop. This will cause the tapered hole
in the prop shaft retainer to squeeze the prop shaft around the output
shaft. Carefully pull on the prop to make sure it is securely attached
to the output shaft of the gear drive.

SET SCREW TYPE PROP ADAPTER INSTALLATION

Slide the prop adapter over
the output shaft of the gear
drive or motor. Apply a drop
of Great Planes Threadlocker
(GPMR6060) to the set
screws and install them in the
prop adapter, tightening them
against the motor shaft.

Position the motor/front plate
assembly between the
backplate. Measure the distance
from the firewall to the front of
the prop adapter. Attach the
front plate of the motor mount
to the back plate using the eight
6-32x1/2” SHC screws, eight
#6 flat washers and four
aluminum screw plates, spaced
out as far as possible.

Note: Once the motor is mounted in position, the collet type prop
adapter can be removed to allow the cowl to be mounted. This adapter
is easily installed with the cowl already installed.

INSTALL THE BRUSHLESS ESC

10

Mount your ESC in the desired location. Always make sure that the
ESC is positioned so that it gets some cooling air flowing over it. Use
the instructions included with the ESC to correctly connect the ESC.

RIMFIRE MOTOR MAINTENANCE

11

RimFire brushless motors require virtually no maintenance. There are
no brushes to wear out and replace. The precision bearings have a very
long service life and should last a very long time. The internal parts of
the motor should not require any cleaning. The only thing that needs to
be checked is to make sure all the screws and set screws remain tight.

IMPORTANT PRECAUTIONS

12

Once the battery is connected to the ESC, stay clear of the motor and

•

prop.

DO NOT apply an input voltage that exceeds the maximum

•

specification of each motor.

DO NOT apply currents to the motor that exceed the maximum

•

specifications of each motor.

DO NOT allow the input connectors to accidentally touch each other

•

while power is applied to the motor. Make sure all input connections
are insulated electrically.

DO NOT allow water or moisture to enter the motor, as it can cause

•

permanent damage to the motor and possibly short out the attached
ESC.

DO NOT cut the coated wires from the motor. If you must remove

•

the bullet connectors, unsolder them.

Allow the motor to cool after each flight.

•

The motor shaft of the motor will rotate at very high rpm. DO NOT

•

attempt to touch the shaft while it is rotating. If setting up the motor/
ESC on the workbench, make sure the motor is securely attached and
that nothing is attached to the motor shaft BEFORE applying power.

Never attempt to use a damaged motor (having mechanical or

•

electrical defects).

69.72mm

ALUMINUM PROP ADAPTER INCLUDED WITH MOTOR

Mount the aluminum prop adapter
to the motor case using four 3x9mm
SHC screws and threadlocking
compound.

ElectriFly carries a complete line of Ammo (inrunner style) and
RimFire (outrunner style) brushless motors, gear drives, motor
mounts, prop adapters and speed controls. For a complete list of
these products, check out our web site at:

www.greatplanes.com

www.electrifly.com

or visit your nearest hobby shop that carries the full line of Great
Planes and ElectriFly products.

Entire Contents © 2009 GPMZ0030Instr