Transcript Switching From Glow to Gas

Switching From Glow to
Gas
My thought process involved in making a major
change in the hobby.
A. Zalner
1/26/2011
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Increasing cost of glow fuel
Glow fuel mess ruins airplanes
Glow engines require more field
equipment (i.e. glow drivers, starters)
Bigger planes fly better
New gas engines cost less than large glow
engines
Why Switch to Gas?
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Until recently you needed to go with a
50cc size engine for decent performance
These engines were very expensive (DLA,
BME, Brison, 3W)
50cc size airplanes require larger, more
expensive servos
The 50cc size airplanes are quite
expensive
50cc size airplanes are quite large (81”
wingspan)
What size engine to go with?
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Quarter scale has been around for a long
time
Reasonable size – 72” wingspan
Power typically was from large (fuel
gulping) glow engines
Gas engines for quarter scale were heavy
and lacked power (Zenoah G-26)
Aircraft performance was limited
Don’t need a second mortgage to buy
servos
Is quarter scale a viable option?
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The DLE-30 has created a revolution in
quarter scale power
We now have an engine that can deliver
unlimited performance under $300
Will swing a 19-8 prop at 8000 RPM
There has been an explosion of new
airplanes designed for this power plant
That sealed the deal for me; my new
aerobatic planes would be DLE-30
powered quarter scale
New quarter scale power option
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Wild Hare Hobbies have recognized the need for model aircraft that are
less expensive to build and fly. They have announced the availability of
four excellent aircraft in the quarter-scale size.
Their new 30cc size Edge 540 is a totally new design replacing the older
baby Edge 540T. This new plane features an all new approach to aircraft
in this size range. They are designed to be as light as is possible, flying
weight is under 10 pounds with a DLE-30 gas engine making these the
lightest planes in their class. While the main structure is build light, it's
not too light for a gas engine which means 15 minute flights on 20 cents
worth of pump gasoline.
A new DLE-30 is more than enough power for rocketing pullout from a
hover, and great 3d performance.
These planes feature built-up wings and all wood fuselage construction.
They still retain the features of larger planes with removable wings and
stabs mounted on carbon-fiber tubes. A new design phenolic control
horns and semi-finished CA hinging means that you can complete hinging
and control horn installation in just a few minutes, two of the most time
consuming steps in building a plane.
The planes are beautifully finished and covered in Ultracote, and have
fiberglass cowl and wheel pants, lightweight aluminum landing gears.
They are packaged in a single box to keep shipping costs low.
Wild Hare
Wild Hare Package
The 30cc size Edge 540 is
one of the best 3D planes
made while retaining such
gentle flight characteristics
that it could easily be used as
a flight trainer.
Wingspan
73"
Length
68"
Weight approx.
10 lbs
Hardware
included
Price
$399.00
With DLE-30
$699.00
With digital
servos, prop,
spinner,servo extensions,
A123 battery pack and
switches
$899.00
Mounting the Engine
The engine is mounted to the
firewall using the supplied
aluminum stand-offs.
Wild Hare provides a template
for drilling the mounting holes
for the DLE-30 engine.
I reinforced the firewall with
1/8” wood dowel pins.
The engine is attached with
10-32 socket head cap screws.
I had to rotate the carb 180
deg. from that shown for
better access to throttle arm.
Phenolic horns epoxied into
control surfaces.
Dubro 4-40 swivel ball links on
servo arms.
Heavy duty Dubro servo arms
used on all controls except
rudder.
Carbon fiber rod with titanium
rod ends used on elevators
and ailerons.
Horizontal stab is removable
and is attached with 4-40
bolts.
Control Linkage
Control
Surface
No. of Servo Mfg.
Servos
RDS8000
Channel
Torque @
6 volts
Elevator
2
Hitec HS-5485HB
Digital (Karbonite
Gears)
1 and 7
89 oz.-in.
Aileron
2
Hitec HS-5485HB
Digital (Karbonite
Gears)
2
89 oz.-in.
Rudder
1
Hitec HS-645MG
Analog
4
133 oz.-in.
Throttle
1
Hitec HS-425BB
Analog
3
57 oz.-in.
Ignition
1
Tech Aero Ignition
Battery Eliminator
Circuit (IBEC)
5
N.A.
Control Set-up
"Ultra IBEC" Ignition
Battery Eliminator Circuit
Eliminates the need for a
separate ignition battery and
mechanical on/off switch
Compatible
with the power
requirements of any CDI ignition
module via jumper selectable
voltage output.
 Enhanced flexibility and safety
via transmitter controlled on/off
control of CDI ignition power
from a spare receiver auxiliary
channel.
Tech-Aero
exclusive 4 stage
filtering blocks interference from
CDI ignition noise in the wiring
path to the receiver.
A
high precision, very low
dropout power regulator design
further assures power receiver
bus
isolation
with
superior
performance during peak current
demand.
One
IBEC
model
fits
all:
compatible with any battery
technology commonly used for
radio control use, with a usable
input voltage range from 4.8V to
12V.
Bright 3mm LED CDI power
on/off indicator.
Tank Arrangement
The tank is a 10 oz. Dubro
fitted with a gas stopper.
You can see the filter in the
upper left hand corner.
There is a “tee” in the line
between the tank and filter
which goes to a fuel dot on
the right for re-filling.
The vent line wraps around
the top of the tank to prevent
spillage when plane is in a
nose down attitude.
The yellow tubing is Tygon.
Servo arm is aluminum
from Mpi.
Note A123 battery in the
foreground. May have to
move this around later for
balance.
Pull-Pull Arrangement
Here is a better view of the
layout up front.
You can see the fuel dot on
the right and fuel filter on the
left.
Sitting directly under the “tee”
and to the left of the throttle
servo is the IBEC.
Wires coming out of the switch
and charging jack are in the
lower left foreground.
The ignition module is in the
very top of the picture.
Forward Arrangement
Throttle & choke arrangement
The forward arm is the
throttle and the rear arm is
the choke.
I decided to go with a manual
choke on this plane.
The choke control rod has a Ubend behind the firewall and
exits out back toward the
front.
Ball links are used on both
choke and throttle.
The cable in front is the
connection from the Hall
sensor to ignition module.
Engine Front View
The aluminum bracket on the
left is my homemade choke
control rod support. Note the
rubber grommet to eliminate
metal to metal contact.
The two red Nyrod tubes on
the side are to allow tuning
the carburetor with the cowl
on.
Note the location of the Hall
sensor.
A Pitts style muffler is available, but I ran out of
funding due to my other Winter project – the
Sukhoi-26.
I don’t particularly care for the
4-bolt (metric) prop mounting
arrangement, but you can’t
always get what you want.
Cowl Arrangement
The
cowl
mounting
arrangement is slicker than
snot on a brass doorknob. It
uses two 4-40 socket head
cap
screws
behind
the
bulkhead.
No holes or
exposed hardware.
That’s a 3” Dave Brown
spinner and a 19-8 prop.
Getting Close
I just weighed this baby and it
came in at an incredible 9.3
lbs.
That means that the flying
weight will be less than 10 lbs.
Woohoo!
Ailerons
Elevators
Rudder
High Rate
(3D)
Low Rate
23 deg.
40+ deg.
45 deg.
15 deg.
12 deg.
25 deg.
Recommended Control Throws
Homemade Deflection Meter
Since the recommended
control throws were given in
degrees rather than in inches,
I made my own homemade
deflection meter to set up the
control throws.
Balancing
The plane balanced out
perfectly right on the wing
tube. Did not have to add any
weights fore and aft or move
the battery around.
Checked the lateral balance
and it checked out fine as
well.
It’s ready to go!