Electrics-2012/04

94 Model Aviation April 2012 www.ModelAviation.com
electrics
ELECTRICS Greg Gimlick
[email protected]
By the time you read this, tradeshow
season and the early spring
fly-ins will be in full force. I love
this time of year! Because I get many
questions about building and powering
larger electrics, I thought this might be
a good time to discuss some easy, offthe-
shelf options for doing just that. It’s
easier than you think.
Anything Is Possible
At the risk of sending my editors over
the edge by using this cliché, I’ll say it
anyway: anything is possible now with
electric power. Go to any big event and
you’ll see things that will amaze you.
Joe Nall is still the king of Giant
Scale meets, but it’s no longer void of
electric-powered models, and some
are now prominently displayed during
the noon demos. Let’s get started on
making it easy.
Batteries and Chargers
There is no sense in doing a giant
electric model if you can’t charge the
LiPos with which you’re going to power
it. My big electrics
are 10S and 12S
setups, and there
will be some 15S
setups on the
show circuit this
year. You’ll need to
support those packs and it’s
really quite easy.
I use a combination of
5S and 6S packs wired
in series to make my
big packs. I can charge
them easily on nearly
any good charger and can
do it at the same time if
I use a parallel charging
board such as the one from
Progressive RC. I went to
David Gray at Progressive
RC for a solution to highdemand
charging and he
sold me on what he calls The
Solution—an iCharger 3010B
and Mean Well SE-1000-24 power
supply.
This setup gives me 1000 watts
Big Power Made Easy
The Solution, from
Progressive RC,
includes the iCharger
3010B and a Mean
Well power supply.
The off-the-shelf power system for the author’s huge Robinhood 99.
PLUS:
> A sample project
Right: Everything is securely fastened to the new firewall
and ready to fly. Be sure to secure all of the wires.
96 Model Aviation April 2012 www.ModelAviation.com
ELECTRICS
• PC connectivity: USB port
• Weight: 750 grams
• Dimensions (length x width x
depth): 143 x 123 x 46mm
• Warranty: 1 year
Mean Well SE-1000-24
Specifications:
• Output power: 41.7 amps
continuous, 1000 watts
• Output voltage: 24 volts DC
(adjustable +/- 10% = 22-27.5 volts)
• Input voltage: 90-132 volts AC, 180-
264 volts AC (worldwide use, selected
by switch)
• Protections: short circuit, overload,
over-voltage, over-temperature
• Mean time between failures:
251,600 hours
• Efficiency: 88%
• Discharge current range: 0.05-30.0
amps
• Input voltage range: 4.5-38 volts DC
• Maximum discharge power capacity:
80 watts
• Maximum regenerative discharge:
1000 watts
• Maximum external discharge power
capacity: 1200 watts at 40 volts/30 amps
• Current drain for balancing: less
than 500 mA
• Balance accuracy: less than 10 mV
• LiPo/Li-Ion/LiFe: 1-10 series (up to
12S LiFe in non-balanced mode)
• NiCd/NiMH battery cell count:
1-25 series
• Pb battery cell count: 1-18 series
(2-36 volts)
• Battery setup memories: 10
• Intelligent temperature control: Yes
of capability and is bulletproof in my
experience so far. I love this reasonably
priced setup. Be aware that this power
supply outputs 24 volts, so be sure your
charger can handle the voltage.
Most charger problems I see come
from insufficient power supplies. I’ll
let Red Scholefield (MA’s “The Battery
Clinic” columnist) go down that road
with his column because he’s the real
expert on batteries and chargers, but I
do recommend this setup for your big
models and packs.
iCharger 3010B Specifications
• Maximum charge power capacity:
1000 watts (at input voltage greater than
23 volts; 500 watts at 12 volts)
• Charge current range: 0.05-30.0
amps
Redundant receiver packs and switches
provide the big airplane with plenty of power
and a measure of safety.
Below: Progressive RC’s parallel charging
board handles up to six packs in parallel with
balancing.
Incredible power from the RimFire 50cc motor and XPS 6800 mAh LiPos take the Robinhood
vertical until the pilot is tired of going up.
• Warranty: 2 years
• Weight: 2500 grams
• Dimensions (length x width x
depth): 278 x 127 x 64mm
Because big electrics often also draw
big current, you need to be sure your
LiPo packs are up to the task. This is
one area where I don’t recommend
going cheap. Experiment if you will,
but I go with what others have shown
me to work and with people I can call
or email and get answers.
My 12S and 10S packs are made
from packs by Xtreme Power Systems.
I’m currently using the company’s
newest 65C-rated 6800 mAh LiPo
packs and they really have some punch
to them! They are also competitively
priced against no-name brands from
companies you can’t talk to. ’Nuff said
about that.
Sample Project
I thought it might be easy to discuss a
recent electric-conversion project I did
and how I went about doing it “off-theshelf.”
It is literally off-the-shelf because
it started in my friend Wayne’s shop.
Wayne pulled down an old World
Engines Robinhood 99 airplane he had
used for aerotowing, which was stored
in his rafters for the last 15 years. It had
been powered by several different gas
engines, most recently a DA-50.
I looked it over and it was in good
shape, so the challenge began. I took it
home and cleaned it up to see what I
would need to do. After removing fuel
tanks, old wiring, switches, cobwebs,
etc., I could see it was in excellent
shape. I weighed the airplane and began
to formulate my plan.
There were Futaba servos in the tail
that tested just fine, so I finished it off
with some new digital Futaba servos for
the ailerons and installed my FASST
seven-channel receiver and two LiFe
Source 2100 mAh 6.6-volt receiver
packs in parallel.
Motor Selection
The projected all-up flying weight
of the Robinhood was 32 pounds. This
airplane had been built for the rigors of
gas power and vibrations, and had been
reinforced for towing huge aerotow
Sailplanes. I zeroed in on two choices
from Great Planes: the RimFire 50cc
and 65cc outrunner motors. These make
big power and are reasonably priced.
Modeling both setups in ElectriCalc
and MotoCalc showed that
either would work and the motor
specifications proved it was at the very
top of the 50cc capabilities. I called to
order the 65cc motor and found they
were back ordered. Because mission
accomplishment sometimes overrides
patience, I ordered the 50cc. This
motor’s kV rating is slightly higher at
230 vs. 160, but I thought it would be
okay and it is.
RimFire 50cc Specifications:
• Can diameter: 3.14 inches (80mm)
• Can length: 2.9 inches (75mm)
• Shaft diameter: .39 inches (10mm)
• Mounting space length: 3.44 inches
(87.3mm)
• Rpm/voltage (kV rating): 230
• Input voltage: 33.3-55.5 volts (9-
15S LiPo)
• Connector: 6mm bullet plugs
• Maximum constant current: 110
amps (at 12S)
• Maximum continuous power: 5000
watts
• Maximum surge current: 135 amps
(at 12S)
• Maximum surge power: 6500 watts
• Maximum constant watts: 5000
watts
• Weight: 44.1 ounces (1250 grams)
My surge current is at the limit, but
my constant current is well below the
motor specifications and it remains cool
during the flight.
Controller Choice
When it comes to big ESCs, there
are a few choices, but I stay with
companies that have a proven track
record and those that will support
the ESC should I have a problem.
Big ESCs are not cheap either, and
this is probably one of the biggest
expenditures you run into when doing
Giant Scale electrics.
I chose a Castle Creations ICE
HV-160 for my project. It will easily
handle any abnormal spikes in current
and offers me real-time in-flight data
logging. This is invaluable.
I have much confidence in the HV-
160 because once I accidently set an
airplane up for testing and hit 189
amps on a 12S pack. I didn’t stay
there long and was surprised to see
the current go that high, but the ESC
stood up to the momentary mistake.
Sometimes, although you think you’ve
estimated everything properly, you find
you were wrong. That was the case and
luckily my gear took it.
Kontronik, Castle, Hacker, and Jeti
all make ESCs that will handle a large
model’s requirements, and each has
excellent technical support should you
need it. These are not cheap! There are
some cheap knockoffs out there, but
buyer beware. I don’t like taking risks
with this sort of power setup. Xtreme
Power Systems is going to have a 15S
ESC soon, but I don’t have a release
date.
Propellers
When you get into an airplane this
size, the propeller choices narrow
and become fairly expensive. RASA,
Mejzlik, PT, Engel, Delro, APC, and
Vess all make excellent large propellers
and some of these companies also make
ones for electric power.
I chose a Vess 22a propeller for
my application because they have
a great reputation and are different
from anything else I’ve seen. I’ve
known Robert Vess since the days
when he taught graduate students in
the aerospace engineering school at
North Carolina State University and
he can do some amazing things. He did
aerodynamics work for NASCAR and
the aerospace industry, so he knows his
stuff—and he is an excellent RC pilot.
RimFire motors specifically
recommends not using electric
propellers and I haven’t been able to
get an answer why, but I followed the
company’s recommendation and chose
a Vess propeller. It is a great-performing
propeller and this setup spins it at
8,600 rpm full throttle.
The Results
I could not be happier with the
results of the electric conversion.
Perhaps the most telling thing is that
Wayne flew it and said it performs
better than it had previously with his
gas engines.
The maximum current spikes on the
log were in the 130-amp range, but
the average current for the flight was
roughly 40 amps. This airplane will fly
vertically with no problem and does
beautiful, big, lazy aerobatics.
This is a large airplane, at 99 inches
and 32 pounds, is a real joy to fly.
The International Miniature Aircraft
Association (IMAA) pilots say, “bigger
flies better.” I’ve always flown a variety
of sizes, but this is my biggest electric
and it certainly flies well.
Thanks to Great Planes, Xtreme
Power Systems, Castle Creations, and
Vess Propellers for recommendations
and technical support as I did this offthe-
shelf challenge! We successfully
resurrected a 20-year-old airplane that
has been in storage for 15 years.
Taking Off
Now it’s on to Toledo! I hope to see
you there, and be sure to check out the
equipment I mentioned at the various
booths. There truly is no limit except
what our wallets can absorb.
Sources:
Progressive RC
(443) 228-8379
www.progressiverc.com
Xtreme Power Systems
[email protected]
www.xtremepowersystems.net/index.php
Great Planes Manufacturing
(800) 637-7660
www.greatplanes.com
Castle Creations
(913) 390-6939
www.castlecreations.com
Vess Propellers
[email protected]
www.vessaero.com
Joe Nall
http://joenall.com/
Weak Signals Toledo RC Show
www.toledoshow.com
IMAA
www.fly-imaa.org

94 Model Aviation April 2012 www.ModelAviation.com
electrics
ELECTRICS Greg Gimlick
[email protected]
By the time you read this, tradeshow
season and the early spring
fly-ins will be in full force. I love
this time of year! Because I get many
questions about building and powering
larger electrics, I thought this might be
a good time to discuss some easy, offthe-
shelf options for doing just that. It’s
easier than you think.
Anything Is Possible
At the risk of sending my editors over
the edge by using this cliché, I’ll say it
anyway: anything is possible now with
electric power. Go to any big event and
you’ll see things that will amaze you.
Joe Nall is still the king of Giant
Scale meets, but it’s no longer void of
electric-powered models, and some
are now prominently displayed during
the noon demos. Let’s get started on
making it easy.
Batteries and Chargers
There is no sense in doing a giant
electric model if you can’t charge the
LiPos with which you’re going to power
it. My big electrics
are 10S and 12S
setups, and there
will be some 15S
setups on the
show circuit this
year. You’ll need to
support those packs and it’s
really quite easy.
I use a combination of
5S and 6S packs wired
in series to make my
big packs. I can charge
them easily on nearly
any good charger and can
do it at the same time if
I use a parallel charging
board such as the one from
Progressive RC. I went to
David Gray at Progressive
RC for a solution to highdemand
charging and he
sold me on what he calls The
Solution—an iCharger 3010B
and Mean Well SE-1000-24 power
supply.
This setup gives me 1000 watts
Big Power Made Easy
The Solution, from
Progressive RC,
includes the iCharger
3010B and a Mean
Well power supply.
The off-the-shelf power system for the author’s huge Robinhood 99.
PLUS:
> A sample project
Right: Everything is securely fastened to the new firewall
and ready to fly. Be sure to secure all of the wires.
96 Model Aviation April 2012 www.ModelAviation.com
ELECTRICS
• PC connectivity: USB port
• Weight: 750 grams
• Dimensions (length x width x
depth): 143 x 123 x 46mm
• Warranty: 1 year
Mean Well SE-1000-24
Specifications:
• Output power: 41.7 amps
continuous, 1000 watts
• Output voltage: 24 volts DC
(adjustable +/- 10% = 22-27.5 volts)
• Input voltage: 90-132 volts AC, 180-
264 volts AC (worldwide use, selected
by switch)
• Protections: short circuit, overload,
over-voltage, over-temperature
• Mean time between failures:
251,600 hours
• Efficiency: 88%
• Discharge current range: 0.05-30.0
amps
• Input voltage range: 4.5-38 volts DC
• Maximum discharge power capacity:
80 watts
• Maximum regenerative discharge:
1000 watts
• Maximum external discharge power
capacity: 1200 watts at 40 volts/30 amps
• Current drain for balancing: less
than 500 mA
• Balance accuracy: less than 10 mV
• LiPo/Li-Ion/LiFe: 1-10 series (up to
12S LiFe in non-balanced mode)
• NiCd/NiMH battery cell count:
1-25 series
• Pb battery cell count: 1-18 series
(2-36 volts)
• Battery setup memories: 10
• Intelligent temperature control: Yes
of capability and is bulletproof in my
experience so far. I love this reasonably
priced setup. Be aware that this power
supply outputs 24 volts, so be sure your
charger can handle the voltage.
Most charger problems I see come
from insufficient power supplies. I’ll
let Red Scholefield (MA’s “The Battery
Clinic” columnist) go down that road
with his column because he’s the real
expert on batteries and chargers, but I
do recommend this setup for your big
models and packs.
iCharger 3010B Specifications
• Maximum charge power capacity:
1000 watts (at input voltage greater than
23 volts; 500 watts at 12 volts)
• Charge current range: 0.05-30.0
amps
Redundant receiver packs and switches
provide the big airplane with plenty of power
and a measure of safety.
Below: Progressive RC’s parallel charging
board handles up to six packs in parallel with
balancing.
Incredible power from the RimFire 50cc motor and XPS 6800 mAh LiPos take the Robinhood
vertical until the pilot is tired of going up.
• Warranty: 2 years
• Weight: 2500 grams
• Dimensions (length x width x
depth): 278 x 127 x 64mm
Because big electrics often also draw
big current, you need to be sure your
LiPo packs are up to the task. This is
one area where I don’t recommend
going cheap. Experiment if you will,
but I go with what others have shown
me to work and with people I can call
or email and get answers.
My 12S and 10S packs are made
from packs by Xtreme Power Systems.
I’m currently using the company’s
newest 65C-rated 6800 mAh LiPo
packs and they really have some punch
to them! They are also competitively
priced against no-name brands from
companies you can’t talk to. ’Nuff said
about that.
Sample Project
I thought it might be easy to discuss a
recent electric-conversion project I did
and how I went about doing it “off-theshelf.”
It is literally off-the-shelf because
it started in my friend Wayne’s shop.
Wayne pulled down an old World
Engines Robinhood 99 airplane he had
used for aerotowing, which was stored
in his rafters for the last 15 years. It had
been powered by several different gas
engines, most recently a DA-50.
I looked it over and it was in good
shape, so the challenge began. I took it
home and cleaned it up to see what I
would need to do. After removing fuel
tanks, old wiring, switches, cobwebs,
etc., I could see it was in excellent
shape. I weighed the airplane and began
to formulate my plan.
There were Futaba servos in the tail
that tested just fine, so I finished it off
with some new digital Futaba servos for
the ailerons and installed my FASST
seven-channel receiver and two LiFe
Source 2100 mAh 6.6-volt receiver
packs in parallel.
Motor Selection
The projected all-up flying weight
of the Robinhood was 32 pounds. This
airplane had been built for the rigors of
gas power and vibrations, and had been
reinforced for towing huge aerotow
Sailplanes. I zeroed in on two choices
from Great Planes: the RimFire 50cc
and 65cc outrunner motors. These make
big power and are reasonably priced.
Modeling both setups in ElectriCalc
and MotoCalc showed that
either would work and the motor
specifications proved it was at the very
top of the 50cc capabilities. I called to
order the 65cc motor and found they
were back ordered. Because mission
accomplishment sometimes overrides
patience, I ordered the 50cc. This
motor’s kV rating is slightly higher at
230 vs. 160, but I thought it would be
okay and it is.
RimFire 50cc Specifications:
• Can diameter: 3.14 inches (80mm)
• Can length: 2.9 inches (75mm)
• Shaft diameter: .39 inches (10mm)
• Mounting space length: 3.44 inches
(87.3mm)
• Rpm/voltage (kV rating): 230
• Input voltage: 33.3-55.5 volts (9-
15S LiPo)
• Connector: 6mm bullet plugs
• Maximum constant current: 110
amps (at 12S)
• Maximum continuous power: 5000
watts
• Maximum surge current: 135 amps
(at 12S)
• Maximum surge power: 6500 watts
• Maximum constant watts: 5000
watts
• Weight: 44.1 ounces (1250 grams)
My surge current is at the limit, but
my constant current is well below the
motor specifications and it remains cool
during the flight.
Controller Choice
When it comes to big ESCs, there
are a few choices, but I stay with
companies that have a proven track
record and those that will support
the ESC should I have a problem.
Big ESCs are not cheap either, and
this is probably one of the biggest
expenditures you run into when doing
Giant Scale electrics.
I chose a Castle Creations ICE
HV-160 for my project. It will easily
handle any abnormal spikes in current
and offers me real-time in-flight data
logging. This is invaluable.
I have much confidence in the HV-
160 because once I accidently set an
airplane up for testing and hit 189
amps on a 12S pack. I didn’t stay
there long and was surprised to see
the current go that high, but the ESC
stood up to the momentary mistake.
Sometimes, although you think you’ve
estimated everything properly, you find
you were wrong. That was the case and
luckily my gear took it.
Kontronik, Castle, Hacker, and Jeti
all make ESCs that will handle a large
model’s requirements, and each has
excellent technical support should you
need it. These are not cheap! There are
some cheap knockoffs out there, but
buyer beware. I don’t like taking risks
with this sort of power setup. Xtreme
Power Systems is going to have a 15S
ESC soon, but I don’t have a release
date.
Propellers
When you get into an airplane this
size, the propeller choices narrow
and become fairly expensive. RASA,
Mejzlik, PT, Engel, Delro, APC, and
Vess all make excellent large propellers
and some of these companies also make
ones for electric power.
I chose a Vess 22a propeller for
my application because they have
a great reputation and are different
from anything else I’ve seen. I’ve
known Robert Vess since the days
when he taught graduate students in
the aerospace engineering school at
North Carolina State University and
he can do some amazing things. He did
aerodynamics work for NASCAR and
the aerospace industry, so he knows his
stuff—and he is an excellent RC pilot.
RimFire motors specifically
recommends not using electric
propellers and I haven’t been able to
get an answer why, but I followed the
company’s recommendation and chose
a Vess propeller. It is a great-performing
propeller and this setup spins it at
8,600 rpm full throttle.
The Results
I could not be happier with the
results of the electric conversion.
Perhaps the most telling thing is that
Wayne flew it and said it performs
better than it had previously with his
gas engines.
The maximum current spikes on the
log were in the 130-amp range, but
the average current for the flight was
roughly 40 amps. This airplane will fly
vertically with no problem and does
beautiful, big, lazy aerobatics.
This is a large airplane, at 99 inches
and 32 pounds, is a real joy to fly.
The International Miniature Aircraft
Association (IMAA) pilots say, “bigger
flies better.” I’ve always flown a variety
of sizes, but this is my biggest electric
and it certainly flies well.
Thanks to Great Planes, Xtreme
Power Systems, Castle Creations, and
Vess Propellers for recommendations
and technical support as I did this offthe-
shelf challenge! We successfully
resurrected a 20-year-old airplane that
has been in storage for 15 years.
Taking Off
Now it’s on to Toledo! I hope to see
you there, and be sure to check out the
equipment I mentioned at the various
booths. There truly is no limit except
what our wallets can absorb.
Sources:
Progressive RC
(443) 228-8379
www.progressiverc.com
Xtreme Power Systems
[email protected]
www.xtremepowersystems.net/index.php
Great Planes Manufacturing
(800) 637-7660
www.greatplanes.com
Castle Creations
(913) 390-6939
www.castlecreations.com
Vess Propellers
[email protected]
www.vessaero.com
Joe Nall
http://joenall.com/
Weak Signals Toledo RC Show
www.toledoshow.com
IMAA
www.fly-imaa.org