Radio Control Helicopters - 2004/06

134 MODEL AVIATION
HAVE YOU EVER flown helicopters out
in the snow? You can watch the blade
wash in the ground effect, and watch it
carry the snow up over the model, through
the blades, and down into the mechanics.
Nice. Nice mess.
It is the end of January as I am writing
this, and we’ve had one heck of a winter
here in central New York so far. It’s not
even half over. Now, I like to go out and
play in the snow (I’m a snowmobile
addict) as much as anybody, but this is
getting a little ridiculous. It will be June,
after this issue is published, before it
completely melts. It makes for long nights
sitting in front of the simulator.
Last month I wrote about doing a basic
aerobatic setup for your helicopter and the
transmitter program. After the lengthy
discussion, I went through the basic
mechanics of a roll. This month I’m going
to take you through doing your first loop.
Don’t worry; this won’t take long. I’ve got
some other interesting stuff to write about,
so push ahead to that if you’ve been
through this before.
I won’t review the setup I detailed last
time; I don’t have enough space for all
that. Dig up the May 2004 issue and reread
it if you need to. What I will go over again
is the necessity of being comfortable
flying around in Idle Up mode, where low
stick is no longer low throttle.
You’ll find that when you try to come
out of forward flight in Idle Up, you may
get an engine overspeed condition. As the
helicopter’s momentum tends to speed up
the blades with the negative pitch at less
than one-quarter stick, it can carry the
engine speed up along with it. It’s just
Dan Williams, 27 Treeline Dr., Liverpool NY 13090; E-mail: [email protected]
RADIO CONTROL HELICOPTERS
The new CSM SL560 Micro gyro looks lost
in the box. It comes with all the PC
interface hardware and software.
The GWS tail-rotor motor/speed controller
on the Hornet.
On the underside of the Hornet you can see the CSM SL560
Micro gyro and the Thunder Power Li-Poly batteries. Vigor Fat Boy (90-size machine) and Lil’ Boy (Hornet).
something of which you should be aware.
You probably want to switch back to
Normal mode for getting back into a
hover. Also, you want to be comfortable
flying around in rather high-speed flight at
a healthy altitude and be able to maintain a
straight track as you make a pass in front
of you.
Doing a loop requires much the same
left stick movement as the roll does. As
the helicopter gets vertical pointing up, the
left stick will be at approximately onequarter,
or 0 pitch. As the helicopter goes
inverted, the left stick goes toward low
stick, giving some negative pitch to assist
the helicopter in staying up while inverted
in the top of the loop.
Once the helicopter comes down the
backside of the loop, vertical pointing to
the ground, the left stick will again be at
roughly one-quarter—approximately 0
pitch. Rounding out the loop at the bottom
will require the left stick to be at roughly
the same position as during forward flight:
slightly less than half stick, or below hover
point.
The right stick movement can make or
break the looks of the loop. If you pull
06sig5QXD 3/24/04 11:44 am Page 134
back too fast and too much, you’ll risk just
doing a really small loop or a back flip.
Apply smooth back elevator to get the
helicopter to loop without making it so big
that the model stops forward motion. If
you make the loop so big that you stop the
helicopter while vertical going up, use the
rudder and do a stall turn. That’s a good
bail-out move for that situation when
starting new.
If the helicopter stops while inverted,
continue applying back elevator to get it
moving again. It can be unnerving to have
that happen. It has happened to me plenty
of times. Once you’re in that position,
there’s really nothing else to do except
continue through and finish the loop.
If you’re not using a heading-hold gyro
or are not flying in heading-hold mode and
the tail seems to want to do strange things
while inverted, you have the tail-rotor
compensation incorrect. Check to make
sure that the tail-rotor compensation
causes the tail pitch to increase again as
the left stick approaches low stick, or
negative pitch.
I used to get my helicopter inverted at
the top of the loop and have it do a partial
pirouette while up there. I even crashed
once because of it as I was learning loops.
The best thing I can recommend is to seek
help if you’re unsure. It’s cheaper that
way.
Learning to manage the right stick
while performing the loop will increase the
pleasing look of a proper loop. After the
helicopter starts to come out of the
inverted portion, use the right stick to
round out the last half of the loop.
You’ll find that as the helicopter tends
to slow down in portions of the loop, you
need less elevator to keep the maneuver
looking good but enough to keep the
model moving. That’s really one of the
bigger differences between flying an
airplane and a helicopter: management of
attitude control and airspeed.
In case you haven’t figured it out by
now, you’ll soon see that if your model is
moving forward fast enough when
beginning the loop and has enough
altitude, you could basically just yank back
on the right stick without really doing
anything with the left stick.
It won’t be pretty, and the model will
do a big, ol’ “figure 9,” but you can ease
your mind about panicking and trying to
remember what to do when as long as the
setup is correct. Your helicopter will come
out of the loop significantly lower in
altitude than when it entered, but, as I
airplane and a helicopter: management of
attitude control and airspeed.
In case you haven’t figured it out by
now, you’ll soon see that if your model is
moving forward fast enough when
beginning the loop and has enough
altitude, you could basically just yank back
on the right stick without really doing
anything with the left stick.
It won’t be pretty, and the model will
do a big, ol’ “figure 9,” but you can ease
your mind about panicking and trying to
remember what to do when as long as the
setup is correct. Your helicopter will come
out of the loop significantly lower in
altitude than when it entered, but, as I
mentioned before, altitude is your friend.
Please be careful with yanking the stick
back, though. Try to use all the left stick
movements as well. I have seen loops go
awry and end up in the ground (a true
figure 9) if the setup on the helicopter is
incorrect.
Go ahead and try some aerobatics. If
you’re uncomfortable with the mechanics
of the stick movements, use your
simulator. Get the stick movements
committed to “muscle memory” and make
the reactions instinctive. When panic sets
in while performing your first real loops,
your instincts will take over and you just
have to worry about your nerves. If you’re
not sure your machine is set up correctly
and capable of these basic aerobatics, seek
help.
A bunch of us have been flying CSM
gyros since their beginning. Seeing Bob
Johnston and the boys doing their thing
with the CSM 360 was simply amazing. I
think everybody had to have one then. I
still have a 360 kicking around in a
helicopter. Some people had drifting
issues, but others would be fine. You just
learned to deal with it because of the
awesome holding power in heading-hold
mode. One felt “connected” with the gyro.
Then the CSM 540 came along. The
set-up programming was cool. You could
play with all sorts of parameters through
the PC interface. The drift problem was
eliminated. There are some differences in
opinion about whether it flew better or
worse than the 360. I liked the 540 in my
machines, but I don’t fly competition so
there might have been some issues with
those people.
We’ve flown JR and Futaba gyros.
The Futaba GY-401 became a favorite of
mine because of its nice feel and
simplicity of setup, and it was cheaper
than its big brother, the GY-601. The
GY-401 also had that “connected”
feeling. It was the only gyro to settle my
gasser from the vibrations involved with
the gasoline engine.
Len Sabato recently let us try the new
CSM SL560 Micro gyro. Too small to fit
all the features of the CSM 560, you say?
Nope! It’s approximately a 1-inch cube
and weighs 11 grams! It was placed in a
Raptor which flew with a standard 560.
A JR 8700G super servo was used for the
tail control and remained for the SL560
Micro’s trial.
Because of its small size, the gyro fit
up inside the canopy instead of at the
back of the helicopter in the standard
gyro location. That’s nice because it
keeps the garbage away from the gyro.
The CSM SL560 Micro has the same
easy automatic set-up routine as its big
brother, takes all of five minutes to run
through, and is ready to fly.
The first flight was great! No trim
changes were necessary, and the SL560
had a nice, solid feel. It had rock-solid
holding power through tail slides, flips,
loops, and rolls. It flew every bit as well
as the Futaba GY-601 in the larger
machines. It never had a tendency to drift
or break loose.
Later flights made in temperature
extremes and swings (a wintertime hazard
in upstate New York) caused no drifting
tendencies. It looks as though the “father
of heading hold” has done it again.
Go to www.bartolo.worldonline.
co.uk/Practheory/Colin Mill-1&2.htm to
read about Colin Mill—who invented all
the CSM gyros—and there’s a great
write-up about theory and workings of the
gyros.
Len Sabato’s site at www.rcmodel
sports.com features an excellent piece
about the setup requirements for the
helicopter as well as the gyro. There’s a
great deal of cool information there.
Len’s new company RC Model Sports is
the importer for all the CSM products, as
well as NHP and KSJ. Check out the Web
page.
The CSM SL560 and the SL560 Micro
come with a PC interface, but it wasn’t
necessary to use in either case. Colin Mill
did his homework, and default settings
with the auto setup routine work out fine
for all except those who like to tinker
with every little thing. We’d rather fly.
The next experiment was to install the
CSM SL560 Micro in a Hornet that had
been causing fits—especially the tail. The
tail had to be calmed before there was
June 2004 137
even a chance of getting the rest sorted out.
It was a huge power drain and it just wasn’t
effective.
The best thing for us to do was dump the
mechanical tail completely and use a GWS
motor/GWS speed controller to run the tail.
Let the SL560 Micro drive the speed
controller: an idea from Ron Osinski. Go to
www.gws.com.tw/ for more information
about GWS products.
The red power wire from the speed
controller receiver connector was removed
and plugged directly into the main power
source. The remaining two wires, signal and
ground, were left in the connector, and the
connector was plugged into the servo port
of the gyro. That was the extent of the
modifications.
On power-up, let the gyro stabilize for a
moment. If you bump the rudder stick, the
tail rotor starts up. Left rudder had to be
held initially until the head speed came up,
but mixing some throttle to rudder
eliminates that problem. Now both of the
motors come up simultaneously.
The Hornet turned into a smooth,
predictable helicopter with plenty of power.
The original mechanical setup was dragging
it down. It’s kind of strange to hear the
GWS motor buzzing from the gyro input.
In all, the changes worked well and the
SL560 Micro performed flawlessly. With
11 grams of weight, it’s perfect for this
application. Go to MS Composit at
www.mscomposit-usa.com for more
information about the Hornet.
After the Hornet got a new lease on life,
some upgrades were in order. A hollow
main shaft, carbon-fiber radio tray, and
Vigor-style canopy came from DeeTee
Enterprises at www.deeteeenterprises.com.
Dennis, the owner, will give you all the
information you need.
Ray Stacy has offered his E-mail
address for anyone who wants to know
more about the Hornet and setup; you can
contact him at [email protected].
He’s running Li-Poly batteries and all the
latest cool stuff for small electric
helicopters. He gave me a few pictures of
the Hornet and the installation, and I have
included them here.
One more thing about the pictures:
check out John Dennis’s custom-painted
canopy for his Vigor from CanopyFX!
That’s too cool. I hate painting canopies.
Check them out at www.canopyfx.com.
That’s pretty much it for this month. I
hope the shows coming up will have many
cool helicopters and accessories; I’ll try to
stuff all the information into this column.
Until then, don’t stuff your tail rotor into
the snow. MA