cowl is now fully "dressed" with the official
RCU logo made by RC Graphics Zone
Note the "Danger High Voltage" label to
keep my glow-powered buddies at bay
Parallel Connector Modules have been re-fitted to
allow a spare plug on each bank, 6s and 4s, for easy
charging. After the hatch is removed, you simply pull
the ESC connector and then plug into the 4s module
for charging and the 6s module for charging. The packs
up front are secured on both sides by Velcro so I
can adjust the CG as needed for testing the 1/4lb
heavier AXI 5330 motor. Additionally, the 2.1AH cell
packs can be easily swapped with newer SKYVOLTS packs
from FMA Direct when they become available.
5330 = 23oz
40 = 19oz
power guru, Steve Neu, published information in his
"Power On" column in the March 2005 issue
of Quiet Flyer magazine which plots the AXI 5330 and
the Actro 60 motor power curves. (see page 60) Both
motors had efficiencies around 87% at 50amps on a
10s Lithium voltage under load of 35 volts. This provides
an output power to the prop of 1522 watts with an
input power of just 1750 watts. Note that Steve's
50amp (1700 watt) limit was likely due to the Jeti
77-amp ESC on a 10s Lithium voltage of 35v (been there,
done that in Part 1). He suggested that the AXI motor
can likely handle higher currents if you keep an eye
on motor cooling.
reading Steve's column, I was now convinced that the
AXI 5330 motor is the correct choice for my Edge 540
conversion. For only $249 at Hobby
Lobby, including several prop adapters, this motor
will be hard to beat for reducing the cost of giant
scale conversions to electric power. The AXI 5330
motor runs at 87% efficiency for just under 2000 watts.
This means that little power is being lost as heat.
I expect to easily have 3000 watt burst power levels
which will provide 150 watts/lb. on my Edge 540. I
selected the 5330/18 because it will have thicker
wires to handle more burst current.
my conversion project, the theme is about lower cost
and the AXI 5330 at $250 U.S. is much lower in price
than even the smaller Actro 40 motor at $350 U.S.
The Actro 60 is even more costly at $480 US at Hobby
for the Plane:
help protect my 1/3 scale Edge 540 during transport
or even when moving it through doorways, I used
the Wing and Tail Cover Set (HAN6010)
from Horizon Hobby. Each set includes nylon padded
bags for two wing halves, the horizontal stabilizers
and the vertical stabilizer. The wing bags comes
with a Velcro strap for a secure fit that won't
let the bag slip off. An additional strap is used
to help carry the bag. Big models are a big investment
and Hangar 9's wing bag set is a handy way to
help protect that investment while still looking
for the Packs:
lithium packs can be risky. You risk damaging the
pack in the event of a crash which reduces your investment
security at the same time as it increases the risk
of fire. I still crash on occasion so my plan for
protecting the exposed packs is to wrap them in a
super impact absorber from FMA
Direct called IMPAD. It is packaged in 12"
x 6" sheets and can protect an egg from cracking
when dropped at four feet off the ground.
pack heat is not an issue (e.g. you are not stressing
the pack in the application), the pack can be wrapped
in an IMPAD pouch using a simple Velcro strap to hold
the pack inside the pouch. When pack heat is an issue,
IMPAD end-caps can be made to allow air flow through
the cells in the pack while protecting it from a blunt
force. For either technique, I used clear shipping
tape to form the pouch or caps.
mount my AXI 5330 motor, I took my usual trip to the
local home improvement store. I found that 4" PVC
caps (Schedule D) were flat on the ends. If I connected
two caps to a custom cut section of 4" PVC pipe,
I could extend the motor to the required 5-3/4"
needed for the spinner backplate when using an AXI 5330
concept was simple, light, solid, adjustable in length,
and most of all, very inexpensive!
AXI 5330 motor comes with a sticky back template for
mounting. I simply placed the decal on a 4" cap
after first sanding the lettering on the surface flat.
some added support, I used two small metal strips
in addition to using washers with my M4 screws. Locktite
was used on all threaded surfaces. I pulled as hard
as I could on the motor and it would not budge. I
felt confident in the ruggedness of my PCV mount.
mounted the other end cap to the firewall using the
same 1/4-20 t-nuts from my original mounting scheme
but with some short screws and washers instead of
the long bolts. I didn't glue the PVC pipe to the
end cap because the fit is so tight that it must be
tapped with a hammer to be fully inserted. I did,
however, secure it with four #8 sheet metal screws,
one in each quadrant.
that the mount may not look centered but the thrust angle
built into the plywood motor box makes the prop adapter
come out centered through the cowl.
finished mounting the AXI 5330 motor by tapping the 4"
PVC end cap onto the pipe with a hammer. I then added
the four #8 sheet metal screws to keep it secure. The
alignment to the cowl was perfect but I needed to open
the holes on my red CBA 4" spinner aluminum backplate
and APC 20x11 prop to the wider 12mm shaft on the prop
adapter. This will require using a drill press or lathe
to keep the holes centered. Since the AXI prop adapters
are already tapped for a M4 spinner cap , so no adapter
is needed. To drill out the perfect size center hole in
my prop, I used a 15/16" drill bit for my 12mm adapter.
A key piece of my lower cost power system for giant-scale
conversions is now sold through Hobby Lobby. The new Jeti
Advance 90 PLUS ESC is a solid 4oz controller that should
handle continuous power levels up to 4200 watts with little
the other Jeti Advance PLUS ESCs, the 90-amp ESC comes without
shrinkwrap for superior heat release and mounting tabs with
my Kokam 10s3p 6.3AH Lithium pack is also rated for 4200
watts continuous (35v * 120a), the weak link in the power
system is now the AXI 5330 motor. By weak, I mean that the
motor will handle 2000 watts continuous and probably up
to 3000 watts peak based upon reports from competitors in
Europe. The overall result will provide a power level of
150w/lb to my 1/3-scale Edge 540 at an unprecedented lower
set out the components for my power system and started preparing
the ESC by soldering the mating connectors for the AXI motor
and a Dean's Ultra connector for the battery. The ESC mounted
easily with some servo tape and a screw through one of the
grommets into the wooden motor box. The wires were not long
enough to use the other eyelets and I felt that they were
not needed. The ESC was now positioned directly in the air
flow through the cowl.
6s and 4s battery packs mounted as before except this time
I used some Velcro straps to secure the outer packs. I had
an additional 8oz up front over my last power system due
to the heavier AXI motor and Jeti ESC. This could only help
move the CG toward the recommended spot as I was a bit tail
heavy with my old setup.
new Jeti Advance PLUS ESC was easy to set up with the compact
Jeti Programming Card. You simply set the jumpers, connect
the control cable, and power up the ESC for 1 second until
you hear a beep. The credit card size programming device
can be easily stored in your field box for future changes.
used the following settings.
Timing for Outrunners
made up some EPP foam caps to cover the extra connector
pins when not recharging the Lithium packs. My 10s3p 6.3AH
Lithium pack is split into a 4s section and a 6s section
which requires two chargers to recharge the pack. This same
setup can be used when I switch to the newer Skyvolts packs
from FMA Direct with taps for cell balancing. One advantage
of using the 4s/6s split configuration is that I can supply
power to my FMA Power Force regulator to test the servos
without arming the powerful motor. This level of safety
is required for indoor testing of the control surfaces.
aluminum backplate and prop fit perfectly after boring them
to 12mm (15/16") for the AXI shaft. I discovered that
the center of the shaft is tapped for an M4 x .7 screw.
To mount my large 4" diameter CB/Tatone spinner, I
would need an M4 screw about 90mm long!
a 90mm long M4 screw proved too difficult in the U.S. I
gave up after only finding a 70mm length and changed my
technique to use a #10-32 screw. The length needed is 3-1/4"
long but 3-1/2" long will work also. I decided that
re-tapping the M4 threaded hole in the AXI 5330 prop adapter
is not all that unreasonable. A size #10 is the next larger
American size from an M4 thread. The adapter was easily
re-tapped to the American standard size #10.
connected my wattmeter and it appeared that my APC 20x11
prop was a reasonable choice after all. I measured 2700
watts at 86amps consistently on four 10 second bursts of
full throttle. I was ready for my maiden flight with the
new power system!