Swash Plate: MIA Micro-FLIGHT Bumble Bee - 2008/02

MORE THAN 30 years ago, Du-Bro
Products Inc. (founder Dewey Broberg)
developed a radio-controlled helicopter
powered by an Ohlsson & Rice chain saw
engine. It was based on a Hughes 300-style
body and controlled by a fixed-pitch rotor
system.
Only a few years before that, Dieter
Schlüter flew the first commercially feasible
radio-controlled helicopter. Since then,
many improvements have made modern
helicopters capable of performing magic in
the air.
That Hughes 300 was my introduction to
RC helicopters. It was big, heavy,
underpowered, and difficult to fly.
Frustration was all too common when just
trying to hold the beast in a hover. The word
“fun” was rarely used with that model.
I never lost the ambition to have fun with
a helicopter, though. As the years passed
and technology moved forward I tried a few
more helicopters, but the fun factor was still
missing—until the Bumble Bee.
I was hooked the first time I saw this
little marvel flown in a small room. Mario I.
Arguello (of MIA Micro-FLIGHT)
designed, developed, and manufactured the
model in Mesa, Arizona. It flew smoothly
and was always under complete control—plenty good enough to do touch-n-gos on a
table and actually climb the stairs.
It reminded me of the way a bee visits a
flower and then goes off to visit another.
Maybe that is where the Bumble Bee got its
name.
I didn’t ask to try to fly it since I still fly
Mode 1, which is throttle on the right
transmitter stick. However, I had to have a
Bumble Bee. I arrived home with a
surprisingly small box full of cool little
goodies, and I was eager to build this 15-
inch-rotor-span helicopter.
Construction: This model’s packaging is
superb; the small parts are grouped in bags
for each assembly step. Some of the parts
are small and do require care not to lose
them. You do not want to have to look for a
00-90 screw on the floor. Open a parts bag
only as necessary.
Included is a precision CNC-milled sheet
of black G-10 fiberglass containing several
parts that should also be handled carefully.
The milling is extremely clean and accurate,
and it produces parts that fit together nicely.
The assembly booklet is well thought out
and guides the reader through the steps to
build a successful model. The construction
drawings are professionally CAD drawn and
are clear and logical. The designer clearly
has an engineering and manufacturing
background.
A major part of the fun factor was
assembling all the frames and bearings and
all the things that make this helicopter fly so
well. It takes some time to build this kit—
not because it is particularly difficult, but
because it is fun to play with the small
assemblies as they go together.
Building a kit, whether it is an airplane, a
boat, or a helicopter, gives one a much
better understanding of how these models
work. I have nothing against “buy-andfly,”
but people are missing out on a large
part of the fun of our hobby by not
spending time at the workbench. Enjoy the
hobby and start building your Bumble Bee.
Read the instruction manual all the way
through to see the whole picture rather than
just separate assembly steps. Prepare the G-
10 parts as described, and the process is on
the way.
The main-frame assembly step seemed to
be the most critical. I spent quite a bit of
time aligning, clamping, and measuring
before any glue touched the structure.
I aligned the top and bottom bearing
blocks, with bearings installed, using the
main rotor shaft before final gluing. I used
medium cyanoacrylate, which worked fine
on the G-10 parts.
Building the tail-rotor gearbox went fine
because I kept the sides aligned with the
carbon shaft before gluing. Next were the
boom assembly to the tail gearbox and themain-frame assembly. With the addition of
the cool landing-gear skids, the Bumble Bee
started to look like a helicopter.
All the little mechanical subassemblies
are in the next steps. Study the drawings
before working on the parts, and pay
attention to all the notes surrounding each
step. This, in a way, parallels the standard
caution carpenters remind themselves of:
measure twice and cut once. The same goes
here. Then things can be spun around for fun
and the builder can make pretend helicopter
noises.
The instructions for the electrical
connections are great. Make sure to test all
connections for the radio, ESC, and gyro
before installation. Now is a good time to
sort out mixing throttle to tail rotor (rudder).
Both the throttle and tail-rotor ESCs must
arm with the throttle stick and trim in the
low position. This way neither motor will
start at a high speed, which would definitely
be bad. The tail rotor and main rotor motors
start at a low speed and increase in speed as
throttle is increased.
Install the radio equipment, making sure
to correctly align the roll and pitch servo
outputs to the swashplate per theinstructions. Check to make sure that the
main and tail-rotor motors run in the correct
direction after all the RC equipment is
installed. Also ensure that the swashplate
movement is correct.
Finish the main blades and balance them
carefully. Extra care with this step will
reduce vibration and increase the Bumble
Bee’s life expectancy. Install the blades to
the rotor head. Press-fit the tail rotor onto the
shaft, and then all that’s left is the canopy.
MIA’s Web site lists a link to a micro
helicopter group, which can be a big help in
the new world of these tiny machines. There
are some great ideas for finishing the canopy
in the picture links. I painted the inside of
my canopy yellow and used MonoKote Trim
Sheets for the decorations per the model on
the kit box.
Now is another good time to go over
every assembly from the beginning to make
sure nothing binds and things move in the
right direction. The preflight preparation step
is crucial!
Now is a good time to tell you not to hold
onto the helicopter by the skids when
running up the motor. The skids only snap
on; remember that. It is safe to hold onto the
main frame aft of the rotor shaft, being
careful not to grind down your fingers on the
main gear. Even the gyro function can be
tested with this method.
With my limited amount of helicopterflying
experience, none within the last 10
years, I was slightly nervous as excuses to
make the first flight ran out. I did all the
preflight checks again, and everything
seemed to be running nicely. I had made a
slight tracking adjustment to one of the
blades, and there was no vibration in the
little Bee.
Flying: Early in the morning, when there
was absolutely no wind, I headed off to a
small, secluded parking lot that was
surrounded by bushes, which would help
keep any breeze to a minimum. With no
more excuses I plugged in the battery and let
the gyro set itself (when the blinking stops),
and then I slowly advanced the throttle until
the Bumble Bee got light on its skids.
There was a definite tendency to spin a
little to the right, and a rudder (tail rotor)-
trim change sorted out that problem easily. I
learned a long time ago that little can be
learned about trim when sliding around on
the ground.
I advanced the throttle a bit more and
the Bumble Bee was flying. There were
more trim adjustments to be made, but
before the first battery pack was exhausted
I had achieved a nearly stable hover.
That’s when I realized I was having fun.
I didn’t get nervous when the model
did a 360 because I knew it wasn’t going
to chop me into little pieces if I lost
control. This little marvel is what I had
been looking for. After more than 15
flights so far, there have been no major
breakages and I have explored forward
flight with a few (planned) figure eights.
Since this is a fixed-pitch helicopter there
are changes to tail-rotor trim when throttle is
changed, but the gyro adjustments smooth
this out nicely, and when in forward flight
little compensation seems needed. Flying
isn’t difficult after some practice.
There are some scratches on the rotor tips
and some readjustments have been made, but
the Bee still looks good. I still fly outdoors
because the weather has been nice, but here
in Phoenix I will have to move indoors soon
and see if I can do touch-n-gos on the
kitchen table.
I highly recommend the Bumble Bee to
anyone who has some RC flying experience
and would like to participate in the building
experience too. This project has certainly
been fun and has brought back some selfconfidence
that left me after my last attempt
at being an RC helicopter pilot. Order a
model from the Web site and have a ball.
Fly safely and have fun! MA
John H. Patton
[email protected]
Manufacturer/Distributor:
MIA Micro-FLIGHT
1626 N. Rowen Cir.
Mesa AZ 85207
(480) 218-6334
www.micro-flight.com