Micro-Flying - 2004/06

GREETINGS, FRIENDS. Despite the
cover date, I am writing this in January
while looking out the window at deep
frozen snow. The wind is blowing, and I am
extremely grateful for a warm house.
I am going to diverge this month from
my usual format and take a look at a new
charger that came my way. I normally leave
reviews up to someone else, but this piece
of equipment has enough features that
many of us would benefit from it.
I am referring to the Orbit
MICROLADER V6.3 battery charger.
Mine came from ICARE at www.icarerc.
com/. They are accommodating people.
The charger is physically well made with
an excellent finish, and the literature—a 38-
page binder booklet with a plastic cover—is
quite complete.
The MICROLADER is furnished with a
set of sturdy leads on the input side, and
they have nice, large clips on the ends. The
output side is a pair of banana jacks, and
you furnish the plugs and leads. I found
what I needed at the RadioShack store—
except for the battery connector, which I
mated to the plug on my pack. I made
several sets of leads, including one for my
transmitter to take advantage of the features
this neat charger offers.
Any time you have plug-in leads there is
the possibility of reverse polarity. The
literature states that the charger is
protected, but I did not test this feature!
I have included the table of
specifications; this may give some
appreciation of the features.
I hope you can see that this is a capable
device! There are several charging modes,
one charge-discharge mode, and one
discharge mode. Five different cell
chemistries are accommodated: Ni-Cd,
NiMH, lead-acid, Li-Poly, and Tadiran.
The first charge mode that appears at
turn-on is rapid automatic charging of Ni-
Cd or NiMH cells. There are two peak
detection values for Ni-Cd and two for
NiMH. The current is not adjustable in this
mode; the charger is designed to detect the
battery parameters and set itself
accordingly.
The next mode is reflex charging with soft
start. This mode is designed for partially
charged Ni-Cd or NiMH cells and avoids the
memory effect possible in Ni-Cds.
The next is discharging with automatic
switch-off/current reducing capacity
measurement (Ni-Cd or NiMH only).
The next mode is format/regeneration of
Ni-Cd or NiMH cells. This mode is
designed for new or rarely used (old)
Dave Robelen
M i c r o - F l y i n g
Route 4, Box 369, Farmville VA 23901; E-mail: [email protected]
The Orbit MICROLADER V6.3 charger has numerous features including several different
charging modes, one charge-discharge mode, and one discharge mode.
Power supply: 11-14VDC (car battery, minimum 55 Ah, or
power adaptor, 13.8V/20 A)
Operating current: Minimum 200 mA, maximum 20 A-12.5VDC
Low/high switch-off voltage: 10-12V/15.0V
Pole confusion protected: Yes (operation disabled)
Connection cables: Highly flexible 2.5mm, with pole clips in red and
black
Charging power: Step-up maximum 180W
Charging current: 50 mA-6.0 A (see appendix)
Charging voltage: 0.5-50V, suitable for 1-50 Ni-Cd cells
@ 1.65V/cell
Discharging power: Maximum 30W (Without cooling fan!)
Discharging current: 50 mA-6.0 A (see appendix)
Discharging voltage: 0.5-45V = 1-30 Ni-Cd cells
Battery pole
confusion protection: Yes (mode won’t start)
Battery connectors: 4mm sockets, red and black
Calibration: via software/EEPROM
Display: LCD, 2 x 16 Characters Volt (V), Ampere (A),
time (hh:mm:ss), charge (mAh)
Operation: Menu-controlled with on/set (double function)
and up and down keys
Message from device: Optical and acoustic
Accessories: PC (RS232) interface 9600/8/1 including PC
software (purchase separately)
Weight (with cables): Approximately 1,200 grams
Dimensions: 160 wide x 50 high x 140 deep (mm)
batteries to prepare them for high-current
use.
The next mode is easy charging with
adjustable current (constant current). This
mode is for the user who wants to set the
current and have automatic peak detection.
(The charger automatically shuts off after
14 hours.) This mode is for Ni-Cd or NiMH
cells only.
The next mode is for lead (Pb) batteries
with adjustable current. It is for batteries
from 1 Ah to 65 Ah offering constant
current, constant voltage limitation
(2.45V/cell), and automatic switch-off after
14 hours.
The next mode is charging of Lithium-
Ion/Polymer-/Tadiran batteries with
adjustable current for Lithium/Tadiran #1-6
cells, Lithium/Polymer #1-6 cells. It
charges with constant current, constant
voltage limitation (3.45 or 4.2V/cell
respectively), and automatic switch-off after
14 hours.
Along with all these processing
programs, there is a plug to connect the
charger to a PC with Windows and a serial
port to get graphic displays of the processes.
As mentioned, this is an optional accessory.
How well does it work? The manual is a
great help in learning how to access the
various processing programs, which are
largely intuitive and well thought out. My
shop power supply is a 12V, 12.5 A
switching supply that I purchased over the
Internet. The charger worked fine with this
supply. After charging/discharging half of
the batteries in my shop, I have a few
observations on the functions.
In general, the various programs are
easily accessible, and each appears to
perform as advertised. I would have
preferred an internal cooling fan; that would
have allowed higher discharge rates to
better simulate electric-drive currents. I was
able to get a maximum of 3.0A with a
seven-cell pack of NiMH cells.
With so much discussion about the safe
charging of Li-Poly cells, I charged several
packs of different capacities and various
levels of charge. In each case, the pack
stayed cool and the peak detection cut off
properly.
When using the automatic charge mode,
the current was somewhat high (3.5 A for a
seven-cell 950 mAh NiMH pack) and the
battery was warmer than normal at the end
of the charge. Not a big deal; I switched to
using the manual mode where I could preset
the current. This charger can handle all sorts
of situations.
My 50 mAh Ni-Cd pack gained capacity
after using the format mode, which was a
good thing.
Overall, the MICROLADER 6.3 is not
the least expensive choice in chargers, but it
is nicely made and presented, and has an
impressive array of options that should fit a
user’s needs for years to come.
I am going to write about models too! My
latest project is a unique micro that I call
the Medley. Basically, it is a medley of
June 2004 89
design shapes that I enjoyed looking at in
the early FF models before RC became
dominant. If you feel you see a particular
model in the lines, that is purely
coincidental.
The wingspan is 22 inches, the area 72
square inches, and it weighs 28.5 grams.
The drive is a KP-00 motor with 6:1
gearing and a 5 x 4 propeller. The battery is
a single 170 mAh Li-Poly and the
receiver/ESC is the JMP narrow-band unit.
The actuators are DWE units from
www.smallrc.com/. In fact, all of the
equipment came from this fine company.
Check out their ever-growing line.
The Medley is a sweetheart to fly. It
cruises at roughly 8-10 mph and can stay
inside of a small gym with ease or ride the
gentle thermals found around the cul-desac
in the evening.
Since I used a design method that
might be of interest, I will share what I
did. In essence, I made a scale model from
sheet balsa, matching the desired outlines,
dihedral, weight, and CG. Gliding this
model around the shop gave me a great
deal of insight on the best CG, the most
suitable dihedral, and the fin size to
match.
To make a scale model such as this
useful, several relationships need to be
observed. You need to decide on a scale
ratio. My Medley was already small, so I
chose 1⁄2 scale. I could have chosen to scale
the area, in which case the square root of
the smaller area would be the scale ratio.
Matching the weight of the anticipated
model in the miniature is helpful to achieve
useful results. In this case it would be the
cube of the chosen scale divided into the
anticipated weight of the larger model. In
my case, 2 cubed = 8, so my test model
should weigh approximately 1⁄8 ounce when
balanced.
It is practical to build the test model
from light material and add weight with
clay, lead, etc. to get the desired value. This
process is called “dynamic scaling” and is
handy in dealing with unknown values in a
new model.
After tossing the “baby” Medley around
my shop and adjusting the incidence angles
and CG, and trimming the fin area, I could
proceed with confidence in building the
larger model.
Try it and you will like it. Simple flat
sheet flying surfaces work fine, and unless
the fuselage of your desired model is really
chunky, a thick profile fuselage is
adequate. Be careful; you might get caught
up having too much fun with the “baby.”
See you at the field when it gets warmer! MA