102 MODEL AVIATION
THIS COLUMN OFFERS one meet
announcement, an Electric Connection
Service (ECS) follow-up, two E-suppliers
of interest, a follow-up on Dump’r and
other electronic projects, clarification of the
April/May noise-testing discussion, an
answer to an often-asked battery question,
and a gleeful “I told ya so.”
Don McGillivray (13371 Sylvan Ave., Fort
Myers FL 33919; Tel.: [239] 481-0063) has
announced the fifth annual Electric Fly-In
and Gathering of E-Flyers scheduled for
October 2-3 in Cape Coral, Florida.
The meet is sponsored by the Cape
Coral R/Sea Hawks, and you can check out
the club’s Web site at www.rseahawks.org.
You can also get more info from Don, and
do be sure to tell him Bob sent ya!
The April column offered one ECS request
from the then-forming Rocky Mountain
Electric Flyers. The ECS encouraged any
interested people to visit that flying site
located at a sports complex in Denver. And
it worked!
According to club Vice President Ron
Evans (1262 Elizabeth St. #204, Denver CO
80206), “Several newbies saw the column
and came out to join us.” The club has since
obtained its AMA charter and has a Web
site—www.rmeflyers.org—that includes
directions to the field, photos, etc.
Something that caught my interest is the
club’s plan to form an electric “exhibition
team.” Its intent is to visit area (read: gas)
flying sites and demonstrate E-everything
from micro/park flyers to hotliners, Scale
models, 3-D aircraft, etc. This sounds like a
good plan that perhaps other E-groups
could execute as well.
The ECS is a column service that is free
to individuals and clubs seeking to connect
with E-others nearby. Send me the
information and I’ll share it with everyone
in a future column. As herein, it works!
A zillion or so electric suppliers have
popped up in recent years—a true testimony
to the amazing growth of E-power interest
and participation. Having been deeply
involved with Electrics since the early
1970s, I’ve seen the industry go from nearly
no E-vendors to the present-day
overwhelming number with an even more
overwhelming array of E-products to offer.
A part of the current vast range of
electric interest is in the amazingly popular
small electric specialty, broadly covered by
terms such as “park,” “backyard,” and
“indoor” flying. These aircraft include all
kinds of subjects, from simple/sport to
detailed scale. This pursuit is so popular
that it supports its own specialty magazines.
Hal Stewart (8198 Speach Dr.,
Baldwinsville NY 13027) has a plans
service that fits into this category; he offers
a catalog of plans for smaller airplanes,
covering Old-Timer, sport, Scale, and other
designs, many of which are E-dedicated or
Bob Kopski, 25 West End Dr., Lansdale PA 19446
RADIO CONTROL ELECTRICS
6
5.5
5
4.5
4
Volts
Minutes
0 20 40 60 80
Discharge curve of typical 500 mAh Ni-Cd receiver pack using Dump’r as 500 mA load and computer interface DVM to record data.
09sig4.QXD 6/23/04 12:55 pm Page 102
otherwise could be E-powered. Other
designs include wet-power specialties such
as 1⁄2A Texaco. For $1.50 you get the
catalog, which gets you a whole lot of fun!
Hobby Lobby International was one of
the earliest vendors on the electric scene,
and the company continues with an everamazing,
ever-expanding catalog largely of
E-stuff. I have catalog 43 on hand, and this
colorful, appetizing, and even artful
presentation begs to be browsed. Those who
have seen this catalog mature throughout
the years will recognize its continuous
growth and expansion of E-product variety.
You can get your own copy for a wellworth-
it $3 by calling Hobby Lobby at
(615) 373-1444 or visiting www.hobbylobby.
com. The downside is that there’s so
much appealing E-stuff that it can be hard
to make a selection—so do be prepared to
suffer this kind of anguish!
Dump’r—a battery discharger presented as
a feature article in the October 2003 MA—
continues to be a reader favorite. (Also see
the December 2003 “Letters to the Editor”
section regarding some errata.) Dump’r is a
safe, effective device designed for packs of
four to 18 Ni-Cd/NiMH cells. Many readers
have built Dump’r, and of those, many have
built more than one.
Every so often I receive one in the mail
to troubleshoot. As I wrote in that article,
I’ll fix any Dump’r free of charge except
postage. Of the roughly 18 Dump’rs I have
received, every one had some assembly
error; a few had multiple such errors. But
all of them worked perfectly after a little
fix-up. If you have a problematic Dump’r,
please send it to me and I’ll help.
In fact, if you have any problematic
September 2004 103
Test setup measures, records battery terminal voltage during
discharge. Curve shape is typical for Ni-Cd, NiMH packs.
Battery, Dump’r, and DVM hookup. Serial cable connector at DVM
interfaces with PC. RadioShack sells similar meters.
09sig4.QXD 6/23/04 12:55 pm Page 103
electronic projects that I have had
published, write to me (with an SASE) and
describe the situation. If I can’t be of help
this way, I’ll invite you to send the offender
to me. The same offer holds: a free fix
except postage. That offer is hard to beat,
wouldn’t you say?
However, there is fine print; my offer of
free help applies to projects built in
accordance with the associated article. If
you do your own thing, deviating from the
published design, I may not be able to help
easily.
I’m not referring to cosmetic/mechanical
creativity, but liberties taken with the
electronic (circuit) design and makeup. If
you have gone this route with your project,
I can still try to help—but only if you send
me accurate, complete, detailed
documentation clearly showing what was
done and how it deviates from the original.
Also, if you’ve done your own thing
incorporating alternate parts, I probably
won’t have them on hand for my otherwise
free fix.
I think my policy of free repair is unique
within aeromodeling, but please appreciate
that it’s based on my confidence with
known designs that are already proven to
work.
The April and May columns included
extensive discussion about power-systeminduced
“noise” problems in Electrics. As
part of this offering, I described an “inshop”
methodology for determining if there
is a problem and even how severe it may
be.
One would normally do a classic range
test on the field to see if noise is a threat to
his or her model. Some reader questions
suggest a need for clarification.
The familiar range test is performed by
distance-checking with the motor off, and
then again with the motor on at partial
power. The question is whether or not the
operating power system produces such
noise interference that range is reduced, and
if so, by how much? The in-shop test
attempts to accomplish what that long field
walk would do, but in a more convenient
setting.
It’s really best to review those April and
May columns, and the August one, before
continuing. To expand on and clarify the athome
test, turning the transmitter off as
described is not to simulate a flyaway
condition, but to give any power-system
noise problems an opportunity to manifest
on the bench.
Power-system noise problems normally
show up under conditions of weak to very
weak signal such as at range limits or more
commonly as the airplane flies through
signal nulls (signal dropouts). The idea
behind turning the transmitter off is to
roughly simulate the latter in-flight
circumstance.
Thus on the bench, with your throttle at
a partial power setting, observing what
happens to the servos and the motor speed
when the transmitter is turned off is one
information input. This observation is then
compared with the same indicators when
the transmitter is turned off without the
motor running.
The desire is for the servo response (any
twitches) and motor response (any sputters
or burps) to be the same for both conditions.
If there is noticeably more servo and motor
reaction to turning the transmitter off at
partial (or higher) throttle, you are
extremely likely to have noise problems.
If this is the case, please give the
recommendations in the April, May, and
August columns a try. There is an excellent
chance that you will see a dramatic
improvement using the recommended
“chokes” solution.
Batteries continue to be a subject of
unceasing reader inquiry. Questions cover
motor packs and often receiver/transmitter
packs as well. A common reader question is
how low the receiver voltage can drop and
still fly safely. As with so many other
things in aeromodeling and life in general,
opinions vary. However, I have some
thoughts to help you decide for yourself.
The accompanying graphic illustrates a
discharge curve for a typical four-cell 500
mAh receiver pack. This curve is from actual
data on such a pack, but the same general
shape typically holds for any Ni-Cd or NiMH
pack of any capacity and any cell count.
104 MODEL AVIATION
Visit the AMA Education Committee
Web site at www.buildandfly.com.
Spo
09sig4.QXD 6/23/04 12:57 pm Page 104
That is, for a given application condition
(discharge condition), the pack terminal
voltage starts “high” following charge and
gradually declines to “low” during use
(discharge). But at what point is the pack
“dead”? Or for a receiver pack, at what
point is it no longer safe to fly?
For receiver packs, I’ve seen answers
ranging from roughly 4.4 volts to as high as
5.0 volts. Looking at several commercially
made expanded scale voltmeters, I find that
the “red” scale can begin at approximately
4.8 volts with variability downward among
brands. My Ace SmarTest uses 4.4 volts as
cutoff. Also, many ESC BECs cut off
somewhere less than 5.0 volts, and 4.5 volts
is common, so clearly the radio stuff is
presumed workable at this level.
No matter the instrument or test method,
the voltage value only has meaning for
packs “under load”; a dedicated test
instrument will typically apply a load
current to the pack that is being tested. If an
ordinary voltmeter were used to read a
pack, some movement of one or more
servos during the test would simulate inflight
conditions.
My choice—when I use receiver packs
at all, which is not often anymore—is
roughly 4.5 volts. I would not stop at 5.0
volts because, judging from the graph, half
or more of the pack capacity remains.
Furthermore, if the pack is prone to
“memory effect” (a classic topic of
considerable debate in which I don’t care to
partake), this is a sure way to cause it!
This has been my take on the subject.
Hopefully it will give you some insight to
help you make your decision.
Returning briefly to the subject of the
amazing growth of Electrics, is it really
“amazing”? For me it’s more like
expected, but the best part for me is that I
told ya so!
Longtime readers know that I’ve always
promoted Electrics with deep and
sometimes forceful conviction—even
through those earlier, leaner years of
minimal interest, if not mockery. To me,
electric power always made sense despite
some beginning marginal or even “powered
sink” flights. I always knew in my heart that
eventually “it had to be.”
Now E-power has enormous industry
support (it’s where the money is) and
enormous participation, but it also goes
head to head with the world-class power
performers. (Please see “2003 NEAT Fair”
in the March 2004 MA.)
For those historically of the “Electric
doesn’t this, that, and the other thing”
belief, it’s time to go silent—with such
thoughts and words and in the pursuit of
aeromodeling; it’s time to go fly an
Electric!
And lest you forget, I told ya so! (Boy,
does that feel good!)
Please enclose an SASE with any
correspondence for which you’d like a
reply. Happy E-landings, everyone! MA
106 MODEL AVIATION
•ON SITE EXPERT ADVICE AND INFORMATION.
•QUALITY MODELING PRODUCTS.
•WE’RE THERE WHEN YOU NEED US.
(WHERE ELSE CAN YOU GET THAT GLOW PLUG ON A SATURDAY MORNING?)
• AMA NEW MEMBERSHIPS & RENEWALS AT PARTICIPATING NRHSA STORES.
•LOCAL CLUB NEWS AND
HAPPENINGS.
•PART OF A NATIONWIDE
ORGANIZATION WORKING FOR
THE BETTERMENT OF THE
HOBBY INDUSTRY.
•HAVE YOU EVER RACED ON A
MAIL ORDER TRACK?
•REMEMBER WHO GOT YOU
STARTED IN R/C?
LOOK FOR YOUR LOCAL
NRHSA HOBBY SHOP
ULTRA BRITE LITES
NEW
NEED
MORE
INFO?
See your hobby retailer or send a #10 S.A.S.E. to
229 E. Rollins Rd. Round Lake Beach, IL 60073
847-740-8726 Fax 847-740-8727
www.RamRCandRamTrack.com
• W h i t e L E D ’ s
•Br i g h t e r • Tougher
• 5 X B a t t e r y L i f e
Flashing Navigation, (3) Lites,
Adj. rate, to 96”, 9V.......................RAM 121 $44.95
“Strobe” Lite, Adj. rate, 9V...............RAM 122 29.95
Landing Lites, (2) w/switch, 9V.......RAM 123 29.95
Giant Scale Nav., (3) to 168”, 9V...RAM 124 39.95
Non Flash Nav., (3) to 96”, 9V.......RAM 125 34.95
Park Flyer Nav., (3) to 48”,
6 grams, 5-8 cells .........................RAM 132 24.95
OWN A MACHINE SHOP
1-800-476-4849
O r V i s i t u s a t w w w.smithy.com
GUARANTEED To pay for itself! FREE!
Info Kit
FREE!
Info Kit
Call
Today!
“I can fix ‘most anything. I don’t know how I lived
without my Smithy. It paid for itself in no time.”
• Easy to use – No
experience
required.
• Versatile – Fix or
make almost anything.
• Affordalbe-- 6
models starting
at $995.
• CNC Compatible
Do It Yourself on a Smithy Lathe•Mill•Drill!
09sig4.QXD 6/23/04 1:00 pm Page 106
Edition: Model Aviation - 2004/09
Page Numbers: 102,103,104,106
Edition: Model Aviation - 2004/09
Page Numbers: 102,103,104,106
102 MODEL AVIATION
THIS COLUMN OFFERS one meet
announcement, an Electric Connection
Service (ECS) follow-up, two E-suppliers
of interest, a follow-up on Dump’r and
other electronic projects, clarification of the
April/May noise-testing discussion, an
answer to an often-asked battery question,
and a gleeful “I told ya so.”
Don McGillivray (13371 Sylvan Ave., Fort
Myers FL 33919; Tel.: [239] 481-0063) has
announced the fifth annual Electric Fly-In
and Gathering of E-Flyers scheduled for
October 2-3 in Cape Coral, Florida.
The meet is sponsored by the Cape
Coral R/Sea Hawks, and you can check out
the club’s Web site at www.rseahawks.org.
You can also get more info from Don, and
do be sure to tell him Bob sent ya!
The April column offered one ECS request
from the then-forming Rocky Mountain
Electric Flyers. The ECS encouraged any
interested people to visit that flying site
located at a sports complex in Denver. And
it worked!
According to club Vice President Ron
Evans (1262 Elizabeth St. #204, Denver CO
80206), “Several newbies saw the column
and came out to join us.” The club has since
obtained its AMA charter and has a Web
site—www.rmeflyers.org—that includes
directions to the field, photos, etc.
Something that caught my interest is the
club’s plan to form an electric “exhibition
team.” Its intent is to visit area (read: gas)
flying sites and demonstrate E-everything
from micro/park flyers to hotliners, Scale
models, 3-D aircraft, etc. This sounds like a
good plan that perhaps other E-groups
could execute as well.
The ECS is a column service that is free
to individuals and clubs seeking to connect
with E-others nearby. Send me the
information and I’ll share it with everyone
in a future column. As herein, it works!
A zillion or so electric suppliers have
popped up in recent years—a true testimony
to the amazing growth of E-power interest
and participation. Having been deeply
involved with Electrics since the early
1970s, I’ve seen the industry go from nearly
no E-vendors to the present-day
overwhelming number with an even more
overwhelming array of E-products to offer.
A part of the current vast range of
electric interest is in the amazingly popular
small electric specialty, broadly covered by
terms such as “park,” “backyard,” and
“indoor” flying. These aircraft include all
kinds of subjects, from simple/sport to
detailed scale. This pursuit is so popular
that it supports its own specialty magazines.
Hal Stewart (8198 Speach Dr.,
Baldwinsville NY 13027) has a plans
service that fits into this category; he offers
a catalog of plans for smaller airplanes,
covering Old-Timer, sport, Scale, and other
designs, many of which are E-dedicated or
Bob Kopski, 25 West End Dr., Lansdale PA 19446
RADIO CONTROL ELECTRICS
6
5.5
5
4.5
4
Volts
Minutes
0 20 40 60 80
Discharge curve of typical 500 mAh Ni-Cd receiver pack using Dump’r as 500 mA load and computer interface DVM to record data.
09sig4.QXD 6/23/04 12:55 pm Page 102
otherwise could be E-powered. Other
designs include wet-power specialties such
as 1⁄2A Texaco. For $1.50 you get the
catalog, which gets you a whole lot of fun!
Hobby Lobby International was one of
the earliest vendors on the electric scene,
and the company continues with an everamazing,
ever-expanding catalog largely of
E-stuff. I have catalog 43 on hand, and this
colorful, appetizing, and even artful
presentation begs to be browsed. Those who
have seen this catalog mature throughout
the years will recognize its continuous
growth and expansion of E-product variety.
You can get your own copy for a wellworth-
it $3 by calling Hobby Lobby at
(615) 373-1444 or visiting www.hobbylobby.
com. The downside is that there’s so
much appealing E-stuff that it can be hard
to make a selection—so do be prepared to
suffer this kind of anguish!
Dump’r—a battery discharger presented as
a feature article in the October 2003 MA—
continues to be a reader favorite. (Also see
the December 2003 “Letters to the Editor”
section regarding some errata.) Dump’r is a
safe, effective device designed for packs of
four to 18 Ni-Cd/NiMH cells. Many readers
have built Dump’r, and of those, many have
built more than one.
Every so often I receive one in the mail
to troubleshoot. As I wrote in that article,
I’ll fix any Dump’r free of charge except
postage. Of the roughly 18 Dump’rs I have
received, every one had some assembly
error; a few had multiple such errors. But
all of them worked perfectly after a little
fix-up. If you have a problematic Dump’r,
please send it to me and I’ll help.
In fact, if you have any problematic
September 2004 103
Test setup measures, records battery terminal voltage during
discharge. Curve shape is typical for Ni-Cd, NiMH packs.
Battery, Dump’r, and DVM hookup. Serial cable connector at DVM
interfaces with PC. RadioShack sells similar meters.
09sig4.QXD 6/23/04 12:55 pm Page 103
electronic projects that I have had
published, write to me (with an SASE) and
describe the situation. If I can’t be of help
this way, I’ll invite you to send the offender
to me. The same offer holds: a free fix
except postage. That offer is hard to beat,
wouldn’t you say?
However, there is fine print; my offer of
free help applies to projects built in
accordance with the associated article. If
you do your own thing, deviating from the
published design, I may not be able to help
easily.
I’m not referring to cosmetic/mechanical
creativity, but liberties taken with the
electronic (circuit) design and makeup. If
you have gone this route with your project,
I can still try to help—but only if you send
me accurate, complete, detailed
documentation clearly showing what was
done and how it deviates from the original.
Also, if you’ve done your own thing
incorporating alternate parts, I probably
won’t have them on hand for my otherwise
free fix.
I think my policy of free repair is unique
within aeromodeling, but please appreciate
that it’s based on my confidence with
known designs that are already proven to
work.
The April and May columns included
extensive discussion about power-systeminduced
“noise” problems in Electrics. As
part of this offering, I described an “inshop”
methodology for determining if there
is a problem and even how severe it may
be.
One would normally do a classic range
test on the field to see if noise is a threat to
his or her model. Some reader questions
suggest a need for clarification.
The familiar range test is performed by
distance-checking with the motor off, and
then again with the motor on at partial
power. The question is whether or not the
operating power system produces such
noise interference that range is reduced, and
if so, by how much? The in-shop test
attempts to accomplish what that long field
walk would do, but in a more convenient
setting.
It’s really best to review those April and
May columns, and the August one, before
continuing. To expand on and clarify the athome
test, turning the transmitter off as
described is not to simulate a flyaway
condition, but to give any power-system
noise problems an opportunity to manifest
on the bench.
Power-system noise problems normally
show up under conditions of weak to very
weak signal such as at range limits or more
commonly as the airplane flies through
signal nulls (signal dropouts). The idea
behind turning the transmitter off is to
roughly simulate the latter in-flight
circumstance.
Thus on the bench, with your throttle at
a partial power setting, observing what
happens to the servos and the motor speed
when the transmitter is turned off is one
information input. This observation is then
compared with the same indicators when
the transmitter is turned off without the
motor running.
The desire is for the servo response (any
twitches) and motor response (any sputters
or burps) to be the same for both conditions.
If there is noticeably more servo and motor
reaction to turning the transmitter off at
partial (or higher) throttle, you are
extremely likely to have noise problems.
If this is the case, please give the
recommendations in the April, May, and
August columns a try. There is an excellent
chance that you will see a dramatic
improvement using the recommended
“chokes” solution.
Batteries continue to be a subject of
unceasing reader inquiry. Questions cover
motor packs and often receiver/transmitter
packs as well. A common reader question is
how low the receiver voltage can drop and
still fly safely. As with so many other
things in aeromodeling and life in general,
opinions vary. However, I have some
thoughts to help you decide for yourself.
The accompanying graphic illustrates a
discharge curve for a typical four-cell 500
mAh receiver pack. This curve is from actual
data on such a pack, but the same general
shape typically holds for any Ni-Cd or NiMH
pack of any capacity and any cell count.
104 MODEL AVIATION
Visit the AMA Education Committee
Web site at www.buildandfly.com.
Spo
09sig4.QXD 6/23/04 12:57 pm Page 104
That is, for a given application condition
(discharge condition), the pack terminal
voltage starts “high” following charge and
gradually declines to “low” during use
(discharge). But at what point is the pack
“dead”? Or for a receiver pack, at what
point is it no longer safe to fly?
For receiver packs, I’ve seen answers
ranging from roughly 4.4 volts to as high as
5.0 volts. Looking at several commercially
made expanded scale voltmeters, I find that
the “red” scale can begin at approximately
4.8 volts with variability downward among
brands. My Ace SmarTest uses 4.4 volts as
cutoff. Also, many ESC BECs cut off
somewhere less than 5.0 volts, and 4.5 volts
is common, so clearly the radio stuff is
presumed workable at this level.
No matter the instrument or test method,
the voltage value only has meaning for
packs “under load”; a dedicated test
instrument will typically apply a load
current to the pack that is being tested. If an
ordinary voltmeter were used to read a
pack, some movement of one or more
servos during the test would simulate inflight
conditions.
My choice—when I use receiver packs
at all, which is not often anymore—is
roughly 4.5 volts. I would not stop at 5.0
volts because, judging from the graph, half
or more of the pack capacity remains.
Furthermore, if the pack is prone to
“memory effect” (a classic topic of
considerable debate in which I don’t care to
partake), this is a sure way to cause it!
This has been my take on the subject.
Hopefully it will give you some insight to
help you make your decision.
Returning briefly to the subject of the
amazing growth of Electrics, is it really
“amazing”? For me it’s more like
expected, but the best part for me is that I
told ya so!
Longtime readers know that I’ve always
promoted Electrics with deep and
sometimes forceful conviction—even
through those earlier, leaner years of
minimal interest, if not mockery. To me,
electric power always made sense despite
some beginning marginal or even “powered
sink” flights. I always knew in my heart that
eventually “it had to be.”
Now E-power has enormous industry
support (it’s where the money is) and
enormous participation, but it also goes
head to head with the world-class power
performers. (Please see “2003 NEAT Fair”
in the March 2004 MA.)
For those historically of the “Electric
doesn’t this, that, and the other thing”
belief, it’s time to go silent—with such
thoughts and words and in the pursuit of
aeromodeling; it’s time to go fly an
Electric!
And lest you forget, I told ya so! (Boy,
does that feel good!)
Please enclose an SASE with any
correspondence for which you’d like a
reply. Happy E-landings, everyone! MA
106 MODEL AVIATION
•ON SITE EXPERT ADVICE AND INFORMATION.
•QUALITY MODELING PRODUCTS.
•WE’RE THERE WHEN YOU NEED US.
(WHERE ELSE CAN YOU GET THAT GLOW PLUG ON A SATURDAY MORNING?)
• AMA NEW MEMBERSHIPS & RENEWALS AT PARTICIPATING NRHSA STORES.
•LOCAL CLUB NEWS AND
HAPPENINGS.
•PART OF A NATIONWIDE
ORGANIZATION WORKING FOR
THE BETTERMENT OF THE
HOBBY INDUSTRY.
•HAVE YOU EVER RACED ON A
MAIL ORDER TRACK?
•REMEMBER WHO GOT YOU
STARTED IN R/C?
LOOK FOR YOUR LOCAL
NRHSA HOBBY SHOP
ULTRA BRITE LITES
NEW
NEED
MORE
INFO?
See your hobby retailer or send a #10 S.A.S.E. to
229 E. Rollins Rd. Round Lake Beach, IL 60073
847-740-8726 Fax 847-740-8727
www.RamRCandRamTrack.com
• W h i t e L E D ’ s
•Br i g h t e r • Tougher
• 5 X B a t t e r y L i f e
Flashing Navigation, (3) Lites,
Adj. rate, to 96”, 9V.......................RAM 121 $44.95
“Strobe” Lite, Adj. rate, 9V...............RAM 122 29.95
Landing Lites, (2) w/switch, 9V.......RAM 123 29.95
Giant Scale Nav., (3) to 168”, 9V...RAM 124 39.95
Non Flash Nav., (3) to 96”, 9V.......RAM 125 34.95
Park Flyer Nav., (3) to 48”,
6 grams, 5-8 cells .........................RAM 132 24.95
OWN A MACHINE SHOP
1-800-476-4849
O r V i s i t u s a t w w w.smithy.com
GUARANTEED To pay for itself! FREE!
Info Kit
FREE!
Info Kit
Call
Today!
“I can fix ‘most anything. I don’t know how I lived
without my Smithy. It paid for itself in no time.”
• Easy to use – No
experience
required.
• Versatile – Fix or
make almost anything.
• Affordalbe-- 6
models starting
at $995.
• CNC Compatible
Do It Yourself on a Smithy Lathe•Mill•Drill!
09sig4.QXD 6/23/04 1:00 pm Page 106
Edition: Model Aviation - 2004/09
Page Numbers: 102,103,104,106
102 MODEL AVIATION
THIS COLUMN OFFERS one meet
announcement, an Electric Connection
Service (ECS) follow-up, two E-suppliers
of interest, a follow-up on Dump’r and
other electronic projects, clarification of the
April/May noise-testing discussion, an
answer to an often-asked battery question,
and a gleeful “I told ya so.”
Don McGillivray (13371 Sylvan Ave., Fort
Myers FL 33919; Tel.: [239] 481-0063) has
announced the fifth annual Electric Fly-In
and Gathering of E-Flyers scheduled for
October 2-3 in Cape Coral, Florida.
The meet is sponsored by the Cape
Coral R/Sea Hawks, and you can check out
the club’s Web site at www.rseahawks.org.
You can also get more info from Don, and
do be sure to tell him Bob sent ya!
The April column offered one ECS request
from the then-forming Rocky Mountain
Electric Flyers. The ECS encouraged any
interested people to visit that flying site
located at a sports complex in Denver. And
it worked!
According to club Vice President Ron
Evans (1262 Elizabeth St. #204, Denver CO
80206), “Several newbies saw the column
and came out to join us.” The club has since
obtained its AMA charter and has a Web
site—www.rmeflyers.org—that includes
directions to the field, photos, etc.
Something that caught my interest is the
club’s plan to form an electric “exhibition
team.” Its intent is to visit area (read: gas)
flying sites and demonstrate E-everything
from micro/park flyers to hotliners, Scale
models, 3-D aircraft, etc. This sounds like a
good plan that perhaps other E-groups
could execute as well.
The ECS is a column service that is free
to individuals and clubs seeking to connect
with E-others nearby. Send me the
information and I’ll share it with everyone
in a future column. As herein, it works!
A zillion or so electric suppliers have
popped up in recent years—a true testimony
to the amazing growth of E-power interest
and participation. Having been deeply
involved with Electrics since the early
1970s, I’ve seen the industry go from nearly
no E-vendors to the present-day
overwhelming number with an even more
overwhelming array of E-products to offer.
A part of the current vast range of
electric interest is in the amazingly popular
small electric specialty, broadly covered by
terms such as “park,” “backyard,” and
“indoor” flying. These aircraft include all
kinds of subjects, from simple/sport to
detailed scale. This pursuit is so popular
that it supports its own specialty magazines.
Hal Stewart (8198 Speach Dr.,
Baldwinsville NY 13027) has a plans
service that fits into this category; he offers
a catalog of plans for smaller airplanes,
covering Old-Timer, sport, Scale, and other
designs, many of which are E-dedicated or
Bob Kopski, 25 West End Dr., Lansdale PA 19446
RADIO CONTROL ELECTRICS
6
5.5
5
4.5
4
Volts
Minutes
0 20 40 60 80
Discharge curve of typical 500 mAh Ni-Cd receiver pack using Dump’r as 500 mA load and computer interface DVM to record data.
09sig4.QXD 6/23/04 12:55 pm Page 102
otherwise could be E-powered. Other
designs include wet-power specialties such
as 1⁄2A Texaco. For $1.50 you get the
catalog, which gets you a whole lot of fun!
Hobby Lobby International was one of
the earliest vendors on the electric scene,
and the company continues with an everamazing,
ever-expanding catalog largely of
E-stuff. I have catalog 43 on hand, and this
colorful, appetizing, and even artful
presentation begs to be browsed. Those who
have seen this catalog mature throughout
the years will recognize its continuous
growth and expansion of E-product variety.
You can get your own copy for a wellworth-
it $3 by calling Hobby Lobby at
(615) 373-1444 or visiting www.hobbylobby.
com. The downside is that there’s so
much appealing E-stuff that it can be hard
to make a selection—so do be prepared to
suffer this kind of anguish!
Dump’r—a battery discharger presented as
a feature article in the October 2003 MA—
continues to be a reader favorite. (Also see
the December 2003 “Letters to the Editor”
section regarding some errata.) Dump’r is a
safe, effective device designed for packs of
four to 18 Ni-Cd/NiMH cells. Many readers
have built Dump’r, and of those, many have
built more than one.
Every so often I receive one in the mail
to troubleshoot. As I wrote in that article,
I’ll fix any Dump’r free of charge except
postage. Of the roughly 18 Dump’rs I have
received, every one had some assembly
error; a few had multiple such errors. But
all of them worked perfectly after a little
fix-up. If you have a problematic Dump’r,
please send it to me and I’ll help.
In fact, if you have any problematic
September 2004 103
Test setup measures, records battery terminal voltage during
discharge. Curve shape is typical for Ni-Cd, NiMH packs.
Battery, Dump’r, and DVM hookup. Serial cable connector at DVM
interfaces with PC. RadioShack sells similar meters.
09sig4.QXD 6/23/04 12:55 pm Page 103
electronic projects that I have had
published, write to me (with an SASE) and
describe the situation. If I can’t be of help
this way, I’ll invite you to send the offender
to me. The same offer holds: a free fix
except postage. That offer is hard to beat,
wouldn’t you say?
However, there is fine print; my offer of
free help applies to projects built in
accordance with the associated article. If
you do your own thing, deviating from the
published design, I may not be able to help
easily.
I’m not referring to cosmetic/mechanical
creativity, but liberties taken with the
electronic (circuit) design and makeup. If
you have gone this route with your project,
I can still try to help—but only if you send
me accurate, complete, detailed
documentation clearly showing what was
done and how it deviates from the original.
Also, if you’ve done your own thing
incorporating alternate parts, I probably
won’t have them on hand for my otherwise
free fix.
I think my policy of free repair is unique
within aeromodeling, but please appreciate
that it’s based on my confidence with
known designs that are already proven to
work.
The April and May columns included
extensive discussion about power-systeminduced
“noise” problems in Electrics. As
part of this offering, I described an “inshop”
methodology for determining if there
is a problem and even how severe it may
be.
One would normally do a classic range
test on the field to see if noise is a threat to
his or her model. Some reader questions
suggest a need for clarification.
The familiar range test is performed by
distance-checking with the motor off, and
then again with the motor on at partial
power. The question is whether or not the
operating power system produces such
noise interference that range is reduced, and
if so, by how much? The in-shop test
attempts to accomplish what that long field
walk would do, but in a more convenient
setting.
It’s really best to review those April and
May columns, and the August one, before
continuing. To expand on and clarify the athome
test, turning the transmitter off as
described is not to simulate a flyaway
condition, but to give any power-system
noise problems an opportunity to manifest
on the bench.
Power-system noise problems normally
show up under conditions of weak to very
weak signal such as at range limits or more
commonly as the airplane flies through
signal nulls (signal dropouts). The idea
behind turning the transmitter off is to
roughly simulate the latter in-flight
circumstance.
Thus on the bench, with your throttle at
a partial power setting, observing what
happens to the servos and the motor speed
when the transmitter is turned off is one
information input. This observation is then
compared with the same indicators when
the transmitter is turned off without the
motor running.
The desire is for the servo response (any
twitches) and motor response (any sputters
or burps) to be the same for both conditions.
If there is noticeably more servo and motor
reaction to turning the transmitter off at
partial (or higher) throttle, you are
extremely likely to have noise problems.
If this is the case, please give the
recommendations in the April, May, and
August columns a try. There is an excellent
chance that you will see a dramatic
improvement using the recommended
“chokes” solution.
Batteries continue to be a subject of
unceasing reader inquiry. Questions cover
motor packs and often receiver/transmitter
packs as well. A common reader question is
how low the receiver voltage can drop and
still fly safely. As with so many other
things in aeromodeling and life in general,
opinions vary. However, I have some
thoughts to help you decide for yourself.
The accompanying graphic illustrates a
discharge curve for a typical four-cell 500
mAh receiver pack. This curve is from actual
data on such a pack, but the same general
shape typically holds for any Ni-Cd or NiMH
pack of any capacity and any cell count.
104 MODEL AVIATION
Visit the AMA Education Committee
Web site at www.buildandfly.com.
Spo
09sig4.QXD 6/23/04 12:57 pm Page 104
That is, for a given application condition
(discharge condition), the pack terminal
voltage starts “high” following charge and
gradually declines to “low” during use
(discharge). But at what point is the pack
“dead”? Or for a receiver pack, at what
point is it no longer safe to fly?
For receiver packs, I’ve seen answers
ranging from roughly 4.4 volts to as high as
5.0 volts. Looking at several commercially
made expanded scale voltmeters, I find that
the “red” scale can begin at approximately
4.8 volts with variability downward among
brands. My Ace SmarTest uses 4.4 volts as
cutoff. Also, many ESC BECs cut off
somewhere less than 5.0 volts, and 4.5 volts
is common, so clearly the radio stuff is
presumed workable at this level.
No matter the instrument or test method,
the voltage value only has meaning for
packs “under load”; a dedicated test
instrument will typically apply a load
current to the pack that is being tested. If an
ordinary voltmeter were used to read a
pack, some movement of one or more
servos during the test would simulate inflight
conditions.
My choice—when I use receiver packs
at all, which is not often anymore—is
roughly 4.5 volts. I would not stop at 5.0
volts because, judging from the graph, half
or more of the pack capacity remains.
Furthermore, if the pack is prone to
“memory effect” (a classic topic of
considerable debate in which I don’t care to
partake), this is a sure way to cause it!
This has been my take on the subject.
Hopefully it will give you some insight to
help you make your decision.
Returning briefly to the subject of the
amazing growth of Electrics, is it really
“amazing”? For me it’s more like
expected, but the best part for me is that I
told ya so!
Longtime readers know that I’ve always
promoted Electrics with deep and
sometimes forceful conviction—even
through those earlier, leaner years of
minimal interest, if not mockery. To me,
electric power always made sense despite
some beginning marginal or even “powered
sink” flights. I always knew in my heart that
eventually “it had to be.”
Now E-power has enormous industry
support (it’s where the money is) and
enormous participation, but it also goes
head to head with the world-class power
performers. (Please see “2003 NEAT Fair”
in the March 2004 MA.)
For those historically of the “Electric
doesn’t this, that, and the other thing”
belief, it’s time to go silent—with such
thoughts and words and in the pursuit of
aeromodeling; it’s time to go fly an
Electric!
And lest you forget, I told ya so! (Boy,
does that feel good!)
Please enclose an SASE with any
correspondence for which you’d like a
reply. Happy E-landings, everyone! MA
106 MODEL AVIATION
•ON SITE EXPERT ADVICE AND INFORMATION.
•QUALITY MODELING PRODUCTS.
•WE’RE THERE WHEN YOU NEED US.
(WHERE ELSE CAN YOU GET THAT GLOW PLUG ON A SATURDAY MORNING?)
• AMA NEW MEMBERSHIPS & RENEWALS AT PARTICIPATING NRHSA STORES.
•LOCAL CLUB NEWS AND
HAPPENINGS.
•PART OF A NATIONWIDE
ORGANIZATION WORKING FOR
THE BETTERMENT OF THE
HOBBY INDUSTRY.
•HAVE YOU EVER RACED ON A
MAIL ORDER TRACK?
•REMEMBER WHO GOT YOU
STARTED IN R/C?
LOOK FOR YOUR LOCAL
NRHSA HOBBY SHOP
ULTRA BRITE LITES
NEW
NEED
MORE
INFO?
See your hobby retailer or send a #10 S.A.S.E. to
229 E. Rollins Rd. Round Lake Beach, IL 60073
847-740-8726 Fax 847-740-8727
www.RamRCandRamTrack.com
• W h i t e L E D ’ s
•Br i g h t e r • Tougher
• 5 X B a t t e r y L i f e
Flashing Navigation, (3) Lites,
Adj. rate, to 96”, 9V.......................RAM 121 $44.95
“Strobe” Lite, Adj. rate, 9V...............RAM 122 29.95
Landing Lites, (2) w/switch, 9V.......RAM 123 29.95
Giant Scale Nav., (3) to 168”, 9V...RAM 124 39.95
Non Flash Nav., (3) to 96”, 9V.......RAM 125 34.95
Park Flyer Nav., (3) to 48”,
6 grams, 5-8 cells .........................RAM 132 24.95
OWN A MACHINE SHOP
1-800-476-4849
O r V i s i t u s a t w w w.smithy.com
GUARANTEED To pay for itself! FREE!
Info Kit
FREE!
Info Kit
Call
Today!
“I can fix ‘most anything. I don’t know how I lived
without my Smithy. It paid for itself in no time.”
• Easy to use – No
experience
required.
• Versatile – Fix or
make almost anything.
• Affordalbe-- 6
models starting
at $995.
• CNC Compatible
Do It Yourself on a Smithy Lathe•Mill•Drill!
09sig4.QXD 6/23/04 1:00 pm Page 106
Edition: Model Aviation - 2004/09
Page Numbers: 102,103,104,106
102 MODEL AVIATION
THIS COLUMN OFFERS one meet
announcement, an Electric Connection
Service (ECS) follow-up, two E-suppliers
of interest, a follow-up on Dump’r and
other electronic projects, clarification of the
April/May noise-testing discussion, an
answer to an often-asked battery question,
and a gleeful “I told ya so.”
Don McGillivray (13371 Sylvan Ave., Fort
Myers FL 33919; Tel.: [239] 481-0063) has
announced the fifth annual Electric Fly-In
and Gathering of E-Flyers scheduled for
October 2-3 in Cape Coral, Florida.
The meet is sponsored by the Cape
Coral R/Sea Hawks, and you can check out
the club’s Web site at www.rseahawks.org.
You can also get more info from Don, and
do be sure to tell him Bob sent ya!
The April column offered one ECS request
from the then-forming Rocky Mountain
Electric Flyers. The ECS encouraged any
interested people to visit that flying site
located at a sports complex in Denver. And
it worked!
According to club Vice President Ron
Evans (1262 Elizabeth St. #204, Denver CO
80206), “Several newbies saw the column
and came out to join us.” The club has since
obtained its AMA charter and has a Web
site—www.rmeflyers.org—that includes
directions to the field, photos, etc.
Something that caught my interest is the
club’s plan to form an electric “exhibition
team.” Its intent is to visit area (read: gas)
flying sites and demonstrate E-everything
from micro/park flyers to hotliners, Scale
models, 3-D aircraft, etc. This sounds like a
good plan that perhaps other E-groups
could execute as well.
The ECS is a column service that is free
to individuals and clubs seeking to connect
with E-others nearby. Send me the
information and I’ll share it with everyone
in a future column. As herein, it works!
A zillion or so electric suppliers have
popped up in recent years—a true testimony
to the amazing growth of E-power interest
and participation. Having been deeply
involved with Electrics since the early
1970s, I’ve seen the industry go from nearly
no E-vendors to the present-day
overwhelming number with an even more
overwhelming array of E-products to offer.
A part of the current vast range of
electric interest is in the amazingly popular
small electric specialty, broadly covered by
terms such as “park,” “backyard,” and
“indoor” flying. These aircraft include all
kinds of subjects, from simple/sport to
detailed scale. This pursuit is so popular
that it supports its own specialty magazines.
Hal Stewart (8198 Speach Dr.,
Baldwinsville NY 13027) has a plans
service that fits into this category; he offers
a catalog of plans for smaller airplanes,
covering Old-Timer, sport, Scale, and other
designs, many of which are E-dedicated or
Bob Kopski, 25 West End Dr., Lansdale PA 19446
RADIO CONTROL ELECTRICS
6
5.5
5
4.5
4
Volts
Minutes
0 20 40 60 80
Discharge curve of typical 500 mAh Ni-Cd receiver pack using Dump’r as 500 mA load and computer interface DVM to record data.
09sig4.QXD 6/23/04 12:55 pm Page 102
otherwise could be E-powered. Other
designs include wet-power specialties such
as 1⁄2A Texaco. For $1.50 you get the
catalog, which gets you a whole lot of fun!
Hobby Lobby International was one of
the earliest vendors on the electric scene,
and the company continues with an everamazing,
ever-expanding catalog largely of
E-stuff. I have catalog 43 on hand, and this
colorful, appetizing, and even artful
presentation begs to be browsed. Those who
have seen this catalog mature throughout
the years will recognize its continuous
growth and expansion of E-product variety.
You can get your own copy for a wellworth-
it $3 by calling Hobby Lobby at
(615) 373-1444 or visiting www.hobbylobby.
com. The downside is that there’s so
much appealing E-stuff that it can be hard
to make a selection—so do be prepared to
suffer this kind of anguish!
Dump’r—a battery discharger presented as
a feature article in the October 2003 MA—
continues to be a reader favorite. (Also see
the December 2003 “Letters to the Editor”
section regarding some errata.) Dump’r is a
safe, effective device designed for packs of
four to 18 Ni-Cd/NiMH cells. Many readers
have built Dump’r, and of those, many have
built more than one.
Every so often I receive one in the mail
to troubleshoot. As I wrote in that article,
I’ll fix any Dump’r free of charge except
postage. Of the roughly 18 Dump’rs I have
received, every one had some assembly
error; a few had multiple such errors. But
all of them worked perfectly after a little
fix-up. If you have a problematic Dump’r,
please send it to me and I’ll help.
In fact, if you have any problematic
September 2004 103
Test setup measures, records battery terminal voltage during
discharge. Curve shape is typical for Ni-Cd, NiMH packs.
Battery, Dump’r, and DVM hookup. Serial cable connector at DVM
interfaces with PC. RadioShack sells similar meters.
09sig4.QXD 6/23/04 12:55 pm Page 103
electronic projects that I have had
published, write to me (with an SASE) and
describe the situation. If I can’t be of help
this way, I’ll invite you to send the offender
to me. The same offer holds: a free fix
except postage. That offer is hard to beat,
wouldn’t you say?
However, there is fine print; my offer of
free help applies to projects built in
accordance with the associated article. If
you do your own thing, deviating from the
published design, I may not be able to help
easily.
I’m not referring to cosmetic/mechanical
creativity, but liberties taken with the
electronic (circuit) design and makeup. If
you have gone this route with your project,
I can still try to help—but only if you send
me accurate, complete, detailed
documentation clearly showing what was
done and how it deviates from the original.
Also, if you’ve done your own thing
incorporating alternate parts, I probably
won’t have them on hand for my otherwise
free fix.
I think my policy of free repair is unique
within aeromodeling, but please appreciate
that it’s based on my confidence with
known designs that are already proven to
work.
The April and May columns included
extensive discussion about power-systeminduced
“noise” problems in Electrics. As
part of this offering, I described an “inshop”
methodology for determining if there
is a problem and even how severe it may
be.
One would normally do a classic range
test on the field to see if noise is a threat to
his or her model. Some reader questions
suggest a need for clarification.
The familiar range test is performed by
distance-checking with the motor off, and
then again with the motor on at partial
power. The question is whether or not the
operating power system produces such
noise interference that range is reduced, and
if so, by how much? The in-shop test
attempts to accomplish what that long field
walk would do, but in a more convenient
setting.
It’s really best to review those April and
May columns, and the August one, before
continuing. To expand on and clarify the athome
test, turning the transmitter off as
described is not to simulate a flyaway
condition, but to give any power-system
noise problems an opportunity to manifest
on the bench.
Power-system noise problems normally
show up under conditions of weak to very
weak signal such as at range limits or more
commonly as the airplane flies through
signal nulls (signal dropouts). The idea
behind turning the transmitter off is to
roughly simulate the latter in-flight
circumstance.
Thus on the bench, with your throttle at
a partial power setting, observing what
happens to the servos and the motor speed
when the transmitter is turned off is one
information input. This observation is then
compared with the same indicators when
the transmitter is turned off without the
motor running.
The desire is for the servo response (any
twitches) and motor response (any sputters
or burps) to be the same for both conditions.
If there is noticeably more servo and motor
reaction to turning the transmitter off at
partial (or higher) throttle, you are
extremely likely to have noise problems.
If this is the case, please give the
recommendations in the April, May, and
August columns a try. There is an excellent
chance that you will see a dramatic
improvement using the recommended
“chokes” solution.
Batteries continue to be a subject of
unceasing reader inquiry. Questions cover
motor packs and often receiver/transmitter
packs as well. A common reader question is
how low the receiver voltage can drop and
still fly safely. As with so many other
things in aeromodeling and life in general,
opinions vary. However, I have some
thoughts to help you decide for yourself.
The accompanying graphic illustrates a
discharge curve for a typical four-cell 500
mAh receiver pack. This curve is from actual
data on such a pack, but the same general
shape typically holds for any Ni-Cd or NiMH
pack of any capacity and any cell count.
104 MODEL AVIATION
Visit the AMA Education Committee
Web site at www.buildandfly.com.
Spo
09sig4.QXD 6/23/04 12:57 pm Page 104
That is, for a given application condition
(discharge condition), the pack terminal
voltage starts “high” following charge and
gradually declines to “low” during use
(discharge). But at what point is the pack
“dead”? Or for a receiver pack, at what
point is it no longer safe to fly?
For receiver packs, I’ve seen answers
ranging from roughly 4.4 volts to as high as
5.0 volts. Looking at several commercially
made expanded scale voltmeters, I find that
the “red” scale can begin at approximately
4.8 volts with variability downward among
brands. My Ace SmarTest uses 4.4 volts as
cutoff. Also, many ESC BECs cut off
somewhere less than 5.0 volts, and 4.5 volts
is common, so clearly the radio stuff is
presumed workable at this level.
No matter the instrument or test method,
the voltage value only has meaning for
packs “under load”; a dedicated test
instrument will typically apply a load
current to the pack that is being tested. If an
ordinary voltmeter were used to read a
pack, some movement of one or more
servos during the test would simulate inflight
conditions.
My choice—when I use receiver packs
at all, which is not often anymore—is
roughly 4.5 volts. I would not stop at 5.0
volts because, judging from the graph, half
or more of the pack capacity remains.
Furthermore, if the pack is prone to
“memory effect” (a classic topic of
considerable debate in which I don’t care to
partake), this is a sure way to cause it!
This has been my take on the subject.
Hopefully it will give you some insight to
help you make your decision.
Returning briefly to the subject of the
amazing growth of Electrics, is it really
“amazing”? For me it’s more like
expected, but the best part for me is that I
told ya so!
Longtime readers know that I’ve always
promoted Electrics with deep and
sometimes forceful conviction—even
through those earlier, leaner years of
minimal interest, if not mockery. To me,
electric power always made sense despite
some beginning marginal or even “powered
sink” flights. I always knew in my heart that
eventually “it had to be.”
Now E-power has enormous industry
support (it’s where the money is) and
enormous participation, but it also goes
head to head with the world-class power
performers. (Please see “2003 NEAT Fair”
in the March 2004 MA.)
For those historically of the “Electric
doesn’t this, that, and the other thing”
belief, it’s time to go silent—with such
thoughts and words and in the pursuit of
aeromodeling; it’s time to go fly an
Electric!
And lest you forget, I told ya so! (Boy,
does that feel good!)
Please enclose an SASE with any
correspondence for which you’d like a
reply. Happy E-landings, everyone! MA
106 MODEL AVIATION
•ON SITE EXPERT ADVICE AND INFORMATION.
•QUALITY MODELING PRODUCTS.
•WE’RE THERE WHEN YOU NEED US.
(WHERE ELSE CAN YOU GET THAT GLOW PLUG ON A SATURDAY MORNING?)
• AMA NEW MEMBERSHIPS & RENEWALS AT PARTICIPATING NRHSA STORES.
•LOCAL CLUB NEWS AND
HAPPENINGS.
•PART OF A NATIONWIDE
ORGANIZATION WORKING FOR
THE BETTERMENT OF THE
HOBBY INDUSTRY.
•HAVE YOU EVER RACED ON A
MAIL ORDER TRACK?
•REMEMBER WHO GOT YOU
STARTED IN R/C?
LOOK FOR YOUR LOCAL
NRHSA HOBBY SHOP
ULTRA BRITE LITES
NEW
NEED
MORE
INFO?
See your hobby retailer or send a #10 S.A.S.E. to
229 E. Rollins Rd. Round Lake Beach, IL 60073
847-740-8726 Fax 847-740-8727
www.RamRCandRamTrack.com
• W h i t e L E D ’ s
•Br i g h t e r • Tougher
• 5 X B a t t e r y L i f e
Flashing Navigation, (3) Lites,
Adj. rate, to 96”, 9V.......................RAM 121 $44.95
“Strobe” Lite, Adj. rate, 9V...............RAM 122 29.95
Landing Lites, (2) w/switch, 9V.......RAM 123 29.95
Giant Scale Nav., (3) to 168”, 9V...RAM 124 39.95
Non Flash Nav., (3) to 96”, 9V.......RAM 125 34.95
Park Flyer Nav., (3) to 48”,
6 grams, 5-8 cells .........................RAM 132 24.95
OWN A MACHINE SHOP
1-800-476-4849
O r V i s i t u s a t w w w.smithy.com
GUARANTEED To pay for itself! FREE!
Info Kit
FREE!
Info Kit
Call
Today!
“I can fix ‘most anything. I don’t know how I lived
without my Smithy. It paid for itself in no time.”
• Easy to use – No
experience
required.
• Versatile – Fix or
make almost anything.
• Affordalbe-- 6
models starting
at $995.
• CNC Compatible
Do It Yourself on a Smithy Lathe•Mill•Drill!
09sig4.QXD 6/23/04 1:00 pm Page 106