Frequently Asked Questions-2012/04

www.ModelAviation.com April 2012 Model Aviation 81
electrics
Greg Gimlick
FREQUENTLY ASKED QUESTIONS [email protected]
Bob Aberle
[email protected]
A note to my readers: As you
probably noted, there was not
an FAQ column in the March
2012 issue. Some of the columnists will
now be submitting bimonthly columns.
Content will still be the same, and I will
continue to answer your questions, in
both print and privately, to the best of
my ability. Please realize answers may
take longer.
I will no longer have a preamble each
month. You know how this column
works, so I’m saving some space.
From now on I will get directly to the
questions and answers.
Q545: This excellent question was
submitted by AMA member Fred Mintz.
“I have been in the hobby for a long
time and always in the glow power side
of things. However, I have never been
able to determine what temperature
range of glow plug is best for a given
setup that includes [the] engine size,
rpm operating range, [whether it’s]
two- or four-stroke, [has an] inverted
mounting, [the] cooling method, fuel
nitro content, [or whether it’s] winter/
summer.
“I see advertised everything from
‘ultra hot’ to ‘cold,’ but I don’t have
a clue as to where they are intended
to be used. Without doing extensive
testing (which would be expensive), I
don’t know what range to select to get
the best from my engines.
“The manufacturers may have had a
suggested range, but since I buy most
of my engines secondhand I don’t have
PLUS:
> Doculam or ClearFilm covering
material
> MA archives and search capabilities
> Follow-up on the Castle CC/BEC
Glow Plug Selections
that information available.
“I have the same problem with
glow plugs themselves. If I have a
plug that is unknown, how can I tell
the temperature range for which it
is rated? Is there a place where I can
reference these factors and get a chance
of selecting the correct temperature
range or identifying a plug type? This
would be very helpful when diagnosing
an engine problem or peaking
performance.”
A545: First of all Fred, I’m so happy
to receive a glow-engine question. My
readers have been getting on my case
for concentrating too much on electric
power. I assure you that I always want
to grant equal time, but people have to
keep writing in with questions.
Although I have been away from
glow-engine power for some time, I still
know how to find reference material. In
this case I used the Google search
Right: A few of the glow plugs used today
include (L-R) O.S. No. 8, Fox Miracle Plug, K&B
1S, K&B HP, Nelson Heavy Duty, and the Nelson
NL04. Photo provided by Larry Davidson.
In his December 2011 FAQ column, Bob
omitted showing a switch when using the
Castle Creations CC/BEC as a voltage reducer.
This photo corrects the problem. The battery
goes first to the switch harness, then on
to the CC/BEC, and finally the reduced
voltage output is applied to the RC receiver
and servos. This is a mock-up photo; the
connectors are not functional.
82 Model Aviation April 2012 www.ModelAviation.com
FREQUENTLY ASKED QUESTIONS
Could you give me an idea as to what
this covering is all about and what
properties it has that might make it
worth trying?”
A546: Doculam (which is also known
as ClearFilm) was originally developed
engine. Thank you, Fred, for this
excellent question!
Q546: “Every once in a while I read
about a model covering product
called either Doculam or ClearFilm.
engine with this search request: “Glow
Plug Temperatures for Model Aircraft
Engines.” The extensive results were
surprising.
The best one I noted was from the
Raleigh Durham (North Carolina)
Radio Control club. The title is Glow
Plug Specification (a guide for selecting
the correct glow plug), authored by
James McCarty, Brian Cooper, and
Brian Gardner. It is available on the RC
Universe forum.
It begins by describing all of the
major glow plugs, such as O.S., Fox,
Enya, McCoy, and Rossi. It then goes
into glow-plug usage tips. Questions
are asked such as, “What happens when
your glow plug temperature range is
too hot?” and plug recommendations
are given for specific fuels such as low
nitro and FAI, 10% to 15% nitro, then
high nitro (over 25%).
Additional chapters cover fourstroke
engine glow plugs, idle bars,
and a discussion about cold plugs vs.
hot plugs. I would suggest you start
with this information and then search
beyond that using the Google search
Below: Many spray paints will adhere to the
Doculam. Make a trial application on a test
strip before working with it on your finished
model aircraft.
Right: The clear iron-on covering
material known as Doculam or
ClearFilm offers some interesting
advantages to modelers, as you will
read in this column.
Left: Heat is
required to adhere
the transparent
Doculam to any
wood structure.
In this case, the
iron temperature
setting is nearly
at maximum. The
same applies when
using a hot-air gun.
Right: Doculam
accepts colored
spray paint after
the surface has
been lightly
sanded with
320- or 400-grit
sandpaper, then
wiped clean with
a solvent such
as denatured
alcohol, and
allowed to dry.
Left: Wet newspaper or even paper towel can be used
as a form of masking tape. Here the wet paper has
been applied to the center of the test structure before
spray painting.
as a laminating material for the graphic
arts hobbyist or professional.
Doculam has certain properties that
make it ideal for the model aircraft
enthusiast. It is lightweight. It has a
built-in adhesive that can be applied
to a model aircraft structure using a
hobby-type iron or a hot air gun. As
it comes off a roll, the Doculam has a
slightly milky appearance. After heat is
applied, it turns clear. Doculam takes
a lot of heat to adhere properly. I have
to set my Top Flite iron to maximum
temperature or my heat gun at its
highest setting.
After the Doculam is adhered to a
surface, it can be “shrunk” just like any
hobby-type iron-on material. Although
it has a built-in adhesive, it does not
have any protective backing that needs
be removed. It does not easily stick to
itself until heat is applied, so you get a
break when applying the Doculam to
a structure. It won’t curl up into a ball
like some iron-on coverings.
As applied, the clear finish is
attractive enough, but you might add
some colored trim and be done with it.
Doculam can easily be painted. It will
accept spray paints such as water-based
latex or acrylic enamels, but you should
always make up a test structure and try
your paint before applying it to your
aircraft.
A good technique for painting
Doculam is to first lightly sand the
surface with a 320- or 400-grit paper,
then wipe the surface clean with
either denatured alcohol or common
vinegar. Let the surface dry thoroughly
(preferably overnight) before starting to
apply your spray paint. Do not use any
primer because it does not stick well to
the Doculam surface.
After spray painting an entire surface,
you can apply masking tape and then
spray on trim colors. I read in one
place where a modeler used wetted
newspaper or paper towel as a masking
tape. If you try that, do it first on a test
structure.
The real beauty of using Doculam is
with a scale or scalelike aircraft; there
are many spray-paint colors to choose
from. You can apply gloss or matte clear
finishes later to protect your decals.
After you cover with Doculam, you
don’t need to prime any of the raw
wood. The Doculam does that in one
quick step, which makes the finish
much lighter in weight.
Where can you purchase Doculam
or ClearFilm? It is comparatively
inexpensive. The thinnest version (1.5
mil) is basically what you would want
to use, although, if you were covering
a large model it might be advisable to
go to the heavier 3.0 mil thickness. The
rolls are 25 inches wide. Some suppliers
will sell you 10- or 25-foot rolls. The
usual roll length is 500 feet and some
suppliers will require you to purchase a
minimum of two rolls.
New Creations RC in Texas has 10-
foot rolls for roughly $7.50 (Catalog
No. MATCOV-010). I’ve listed the
company in the “Sources” section. Kirk
Massey of New Creations has a large
website, so it is worth your time to take
a look at it.
I learned of a company called Oregon
Laminating that is willing to sell a single
500-foot x 25-inch wide roll of 1.5
mil Doculam for $45, plus a modest
shipping charge. This would be enough
for practically an entire club, so you
might try buying a roll and selling off
lengths to your club members. I’ve
also listed Oregon Laminating in the
“Sources” section.
If you would like even more
application information concerning
Doculam, I recommend that you try
one of the Internet search engines.
There is a lot of data out there.
Q547: Is there a place I could go to look
up all the past questions and answers
published in your FAQ column?
A547: Eight years ago, when I started
my FAQ column, we were placing all
questions and answers into a section on
the AMA website. I’ve listed the URL in
the “Sources” section. For approximately
two years these posting were made, but
changes in personnel at the magazine
suspended the project.
More than 500 FAQs have appeared
in the pages of MA. I asked editor Jay
Smith if there was any way to pick up
on this? Jay’s answer came as a pleasant
surprise. Jay said, “An archive of every
published issue of Model Aviation will
be made available to our members early
next year. It will have a robust search
engine. This may prove to work well
for members who wish to search for
answers that were published in your
FAQ column.”
I suspect many will read this and say,
“I can’t wait!” As soon as this search
system is up and running, I will report
it to you in this column and provide
instructions for its use. Stay tuned!
Follow-up to Q530, which appeared in
the December 2011 MA on page 76: I
made an error in my December FAQ
column, when discussing the use of the
Castle Creations CC/BEC to reduce the
voltage of a two-cell LiPo battery pack
to a lower, more reasonable voltage
level.
That FAQ was supposed to be
directed to glow-fueled pilots who
wanted to use a two-cell LiPo battery
pack to operate their RC receiver and
servos, but at reduced voltage. The
problem I created in my answer is that
I omitted the RC system switch in my
photo.
I also showed in that photo the
battery going directly to the CC/
BEC voltage reducer. As many of you
pointed out, by doing that I always had
some power being drawn by the CC/
BEC. In my own application, I remove
the battery pack when not flying, and
therefore never use any switch.
A fueled pilot will want to use a
regular RC system switch harness. In
the photo shown in this column, the
battery now goes first to the switch,
then on to the CC/BEC, and finally
onto the battery port of your RC
receiver.
The idle current of the CC/BEC was
measured at only 10 mA, but over a
long period of time, that would have
reduced the battery voltage to a level
that might result in damage to the
battery. I thank AMA member and
reader, Alan Buckner, for being the first
to bring this error to my attention.
Sources:
Glow Plug Specifications
www.rcuniverse.com/forum/m_8376353/
printable.htm
New Creations RC
(936) 856-4630
www.newcreations-rc.com
Oregon Laminations Company
(800) 574-9814
www.oregonlam.com/index.html
Frequently Asked Questions
www.modelaircraft.org/mag/faq/index.asp

www.ModelAviation.com April 2012 Model Aviation 81
electrics
Greg Gimlick
FREQUENTLY ASKED QUESTIONS [email protected]
Bob Aberle
[email protected]
A note to my readers: As you
probably noted, there was not
an FAQ column in the March
2012 issue. Some of the columnists will
now be submitting bimonthly columns.
Content will still be the same, and I will
continue to answer your questions, in
both print and privately, to the best of
my ability. Please realize answers may
take longer.
I will no longer have a preamble each
month. You know how this column
works, so I’m saving some space.
From now on I will get directly to the
questions and answers.
Q545: This excellent question was
submitted by AMA member Fred Mintz.
“I have been in the hobby for a long
time and always in the glow power side
of things. However, I have never been
able to determine what temperature
range of glow plug is best for a given
setup that includes [the] engine size,
rpm operating range, [whether it’s]
two- or four-stroke, [has an] inverted
mounting, [the] cooling method, fuel
nitro content, [or whether it’s] winter/
summer.
“I see advertised everything from
‘ultra hot’ to ‘cold,’ but I don’t have
a clue as to where they are intended
to be used. Without doing extensive
testing (which would be expensive), I
don’t know what range to select to get
the best from my engines.
“The manufacturers may have had a
suggested range, but since I buy most
of my engines secondhand I don’t have
PLUS:
> Doculam or ClearFilm covering
material
> MA archives and search capabilities
> Follow-up on the Castle CC/BEC
Glow Plug Selections
that information available.
“I have the same problem with
glow plugs themselves. If I have a
plug that is unknown, how can I tell
the temperature range for which it
is rated? Is there a place where I can
reference these factors and get a chance
of selecting the correct temperature
range or identifying a plug type? This
would be very helpful when diagnosing
an engine problem or peaking
performance.”
A545: First of all Fred, I’m so happy
to receive a glow-engine question. My
readers have been getting on my case
for concentrating too much on electric
power. I assure you that I always want
to grant equal time, but people have to
keep writing in with questions.
Although I have been away from
glow-engine power for some time, I still
know how to find reference material. In
this case I used the Google search
Right: A few of the glow plugs used today
include (L-R) O.S. No. 8, Fox Miracle Plug, K&B
1S, K&B HP, Nelson Heavy Duty, and the Nelson
NL04. Photo provided by Larry Davidson.
In his December 2011 FAQ column, Bob
omitted showing a switch when using the
Castle Creations CC/BEC as a voltage reducer.
This photo corrects the problem. The battery
goes first to the switch harness, then on
to the CC/BEC, and finally the reduced
voltage output is applied to the RC receiver
and servos. This is a mock-up photo; the
connectors are not functional.
82 Model Aviation April 2012 www.ModelAviation.com
FREQUENTLY ASKED QUESTIONS
Could you give me an idea as to what
this covering is all about and what
properties it has that might make it
worth trying?”
A546: Doculam (which is also known
as ClearFilm) was originally developed
engine. Thank you, Fred, for this
excellent question!
Q546: “Every once in a while I read
about a model covering product
called either Doculam or ClearFilm.
engine with this search request: “Glow
Plug Temperatures for Model Aircraft
Engines.” The extensive results were
surprising.
The best one I noted was from the
Raleigh Durham (North Carolina)
Radio Control club. The title is Glow
Plug Specification (a guide for selecting
the correct glow plug), authored by
James McCarty, Brian Cooper, and
Brian Gardner. It is available on the RC
Universe forum.
It begins by describing all of the
major glow plugs, such as O.S., Fox,
Enya, McCoy, and Rossi. It then goes
into glow-plug usage tips. Questions
are asked such as, “What happens when
your glow plug temperature range is
too hot?” and plug recommendations
are given for specific fuels such as low
nitro and FAI, 10% to 15% nitro, then
high nitro (over 25%).
Additional chapters cover fourstroke
engine glow plugs, idle bars,
and a discussion about cold plugs vs.
hot plugs. I would suggest you start
with this information and then search
beyond that using the Google search
Below: Many spray paints will adhere to the
Doculam. Make a trial application on a test
strip before working with it on your finished
model aircraft.
Right: The clear iron-on covering
material known as Doculam or
ClearFilm offers some interesting
advantages to modelers, as you will
read in this column.
Left: Heat is
required to adhere
the transparent
Doculam to any
wood structure.
In this case, the
iron temperature
setting is nearly
at maximum. The
same applies when
using a hot-air gun.
Right: Doculam
accepts colored
spray paint after
the surface has
been lightly
sanded with
320- or 400-grit
sandpaper, then
wiped clean with
a solvent such
as denatured
alcohol, and
allowed to dry.
Left: Wet newspaper or even paper towel can be used
as a form of masking tape. Here the wet paper has
been applied to the center of the test structure before
spray painting.
as a laminating material for the graphic
arts hobbyist or professional.
Doculam has certain properties that
make it ideal for the model aircraft
enthusiast. It is lightweight. It has a
built-in adhesive that can be applied
to a model aircraft structure using a
hobby-type iron or a hot air gun. As
it comes off a roll, the Doculam has a
slightly milky appearance. After heat is
applied, it turns clear. Doculam takes
a lot of heat to adhere properly. I have
to set my Top Flite iron to maximum
temperature or my heat gun at its
highest setting.
After the Doculam is adhered to a
surface, it can be “shrunk” just like any
hobby-type iron-on material. Although
it has a built-in adhesive, it does not
have any protective backing that needs
be removed. It does not easily stick to
itself until heat is applied, so you get a
break when applying the Doculam to
a structure. It won’t curl up into a ball
like some iron-on coverings.
As applied, the clear finish is
attractive enough, but you might add
some colored trim and be done with it.
Doculam can easily be painted. It will
accept spray paints such as water-based
latex or acrylic enamels, but you should
always make up a test structure and try
your paint before applying it to your
aircraft.
A good technique for painting
Doculam is to first lightly sand the
surface with a 320- or 400-grit paper,
then wipe the surface clean with
either denatured alcohol or common
vinegar. Let the surface dry thoroughly
(preferably overnight) before starting to
apply your spray paint. Do not use any
primer because it does not stick well to
the Doculam surface.
After spray painting an entire surface,
you can apply masking tape and then
spray on trim colors. I read in one
place where a modeler used wetted
newspaper or paper towel as a masking
tape. If you try that, do it first on a test
structure.
The real beauty of using Doculam is
with a scale or scalelike aircraft; there
are many spray-paint colors to choose
from. You can apply gloss or matte clear
finishes later to protect your decals.
After you cover with Doculam, you
don’t need to prime any of the raw
wood. The Doculam does that in one
quick step, which makes the finish
much lighter in weight.
Where can you purchase Doculam
or ClearFilm? It is comparatively
inexpensive. The thinnest version (1.5
mil) is basically what you would want
to use, although, if you were covering
a large model it might be advisable to
go to the heavier 3.0 mil thickness. The
rolls are 25 inches wide. Some suppliers
will sell you 10- or 25-foot rolls. The
usual roll length is 500 feet and some
suppliers will require you to purchase a
minimum of two rolls.
New Creations RC in Texas has 10-
foot rolls for roughly $7.50 (Catalog
No. MATCOV-010). I’ve listed the
company in the “Sources” section. Kirk
Massey of New Creations has a large
website, so it is worth your time to take
a look at it.
I learned of a company called Oregon
Laminating that is willing to sell a single
500-foot x 25-inch wide roll of 1.5
mil Doculam for $45, plus a modest
shipping charge. This would be enough
for practically an entire club, so you
might try buying a roll and selling off
lengths to your club members. I’ve
also listed Oregon Laminating in the
“Sources” section.
If you would like even more
application information concerning
Doculam, I recommend that you try
one of the Internet search engines.
There is a lot of data out there.
Q547: Is there a place I could go to look
up all the past questions and answers
published in your FAQ column?
A547: Eight years ago, when I started
my FAQ column, we were placing all
questions and answers into a section on
the AMA website. I’ve listed the URL in
the “Sources” section. For approximately
two years these posting were made, but
changes in personnel at the magazine
suspended the project.
More than 500 FAQs have appeared
in the pages of MA. I asked editor Jay
Smith if there was any way to pick up
on this? Jay’s answer came as a pleasant
surprise. Jay said, “An archive of every
published issue of Model Aviation will
be made available to our members early
next year. It will have a robust search
engine. This may prove to work well
for members who wish to search for
answers that were published in your
FAQ column.”
I suspect many will read this and say,
“I can’t wait!” As soon as this search
system is up and running, I will report
it to you in this column and provide
instructions for its use. Stay tuned!
Follow-up to Q530, which appeared in
the December 2011 MA on page 76: I
made an error in my December FAQ
column, when discussing the use of the
Castle Creations CC/BEC to reduce the
voltage of a two-cell LiPo battery pack
to a lower, more reasonable voltage
level.
That FAQ was supposed to be
directed to glow-fueled pilots who
wanted to use a two-cell LiPo battery
pack to operate their RC receiver and
servos, but at reduced voltage. The
problem I created in my answer is that
I omitted the RC system switch in my
photo.
I also showed in that photo the
battery going directly to the CC/
BEC voltage reducer. As many of you
pointed out, by doing that I always had
some power being drawn by the CC/
BEC. In my own application, I remove
the battery pack when not flying, and
therefore never use any switch.
A fueled pilot will want to use a
regular RC system switch harness. In
the photo shown in this column, the
battery now goes first to the switch,
then on to the CC/BEC, and finally
onto the battery port of your RC
receiver.
The idle current of the CC/BEC was
measured at only 10 mA, but over a
long period of time, that would have
reduced the battery voltage to a level
that might result in damage to the
battery. I thank AMA member and
reader, Alan Buckner, for being the first
to bring this error to my attention.
Sources:
Glow Plug Specifications
www.rcuniverse.com/forum/m_8376353/
printable.htm
New Creations RC
(936) 856-4630
www.newcreations-rc.com
Oregon Laminations Company
(800) 574-9814
www.oregonlam.com/index.html
Frequently Asked Questions
www.modelaircraft.org/mag/faq/index.asp