Trimming must be done
with little or no wind. Make multiple tests before making adjustments.
Start at the beginning of the list and work down the list for best
results. If any changes are made recheck and adjust previous settings.
CHANGE ONLY ONE THING AT A TIME!!
Control Centering: Fly
straight and level. Use transmitter trims for hands off straight and
level flight. Adjust clevis to center transmitter trims, or reset
computer trims.
Control throws: Fly model
and apply full deflection of each control in turn. Check response of
each control: Aileron hi-rate: 3 rolls in 4 seconds, low rate: 3 rolls
in 6 seconds, Elevator high rate: to give a good and smooth corner, low
rate: to give a loop of approx. 130 foot in diameter, Rudder high rate:
30-35 degrees for stall turns, low rate: to maintain knife edge.
Decalage: Power off vertical
dive, cross wind (if any). Release controls when model is vertical
(elevator trim mush be neutral).
A: Model continues straight down; no adjustment.
B: Model starts to pull nosw up; Reduce wing incidence.
C: Model starts to pull nose down; Increase wing incidence.
Center of gravity:
Method 1: Roll into a near vertically banked turn.
-A: Nose drops; Add tail weight.
-B: Tail drops; Add nose weight.
Method 2: (Simple) Roll inverted.
-A: Lots of down elevator required to maintain level flight. Add tail
weight.
-B: Now down elevator required or plane climbs; Add nose weight.
Tip weight: (course
adjustment) Fly straight and level upright. Adjust aileron trim for
level flight. Roll inverted, level wings and release stick.
A: Model does not drop a wing; No adjustment.
B: Left wing drops; Add weight to right tip.
C: Right wing drops; Add weight to left tip.
Side thrust: Fly away from
you, into any wind and pull vertical.
A: Model continues straight up; No adjustment.
B: Model veers left; Add right thrust.
C: Model veers right; Reduce right thrust.
Up/Down thrust: Fly normal
path into wind, parallel to you, approx 100 yards from you. Elevator
trim should be neutral per test 3. Pull vertical and release elevator.
A: Model continues straight up; No adjustment.
B: Model pitches nose up; Add down thrust.
C: Model pitches nose down; Reduce down thrust.
Tip weight: (fine
adjustment)
Method 1: Fly model as per test 7, and pull into a small loop (1 only)
Method 2: Fly model as per test 7, and push into a small outside loop (1
only)
-A: Model comes out with wings level; No adjustment.
-B: Model comes out with right wing low; Add weight to left tip.
-C: Model comes out with left wing low; Add weight to right tip.
Aileron differential:
Method 1: Fly towards you and pull into a vertical climb. Release
controls, then do a half roll.
-A: No heading changes; No adjustment.
-B: Heading changes to opposite of roll command (veer left after right
roll); Increase differential.
-C: Heading changes in direction of roll command; Reduce differential.
Method 2: Fly model on a normal pass and do three or more rolls.
-A: Roll axis on model center line; No adjustment.
-B: Roll axis off same direction as roll command (right roll, roll axis
off right wing tip); Increase differential.
-C: Roll axis opposite of command; Reduce differential.
A: Model holds knife edge; No adjustment needed.
B: Model rolls in direction of rudder; Reduce dihedral.
C: Model rolls opposite direction of rudder; Add dihedral.
All
about GLOW PLUGS
Written by Brian
Gardiner, and Central Coast Model Aero Club Inc.
Submitted by Wayne Beasley
_________
How Does A Glow Plug Work?
Contrary to what many have
previously been lead to believe the following is
an explanation of how a glow plug functions in a motor. The plug is initially
heated by applying a voltage (typically 1.5 volts) to it. This is to cause it to
glow so as to ignite the fuel at compression and start the internal combustion
cycle.
Once the cycle has started, the power source can be disconnected, as with the
heat generated at combustion the CATALYTIC Reaction generated between \
the methanol and platinum in the plug coils becomes sufficient to keep the
process going. The catalytic reaction is a reaction whereby platinum will glow
in the presence of methyl alcohol vapor. This will happen without any external
power source being applied.
How do you select the correct PLUG
for your application, and why?
To do this you need to understand a little more of the theory behind the
process. In glow fuel the catalytic reaction is generated between the methanol
and platinum only. Castor oil, synthetic oil, nitro methane, etc do not generate
a catalytic reaction with the
platinum.
Next you need to understand that a certain surface area of platinum is
required to generate a sufficient catalytic reaction to keep the internal
combustion process going. Also it is necessary to allow extra surface area for
the reaction to be great enough when it diminishes with the available methanol
dropping as in the case at motor idle. Simply put, cold plugs are manufactured
using a thicker wire to give greater surface area to facilitate a greater
reaction and thus the required catalytic reaction where less methanol is
present in the fuel mixture.
So! More nitro means less methanol which in turn means a greater surface
area to platinum will be required to generate a sufficient catalytic reaction.
Suddenly it all makes sense! To work out which temperature plug to use, you
need to know how much methanol is in
your fuel, not how much nitro or oil.
As a rough rule of thumb;
· 80% methanol or above, use a hot plug.
· 70%-75% use a medium plug.
· 60%-75% use a cold plug.
· 65% or less use a very cold
plug.
Idle Bars and Other Stuff
Again, contrary to what many believe, the idle bar on a glow plug is not
necessarily what its name would suggest. It is in fact to stop any fuel not
vaporized from dousing the platinum coil of the glow plug by dispersing it
away from the coil.
Why are plated coils not as good as
platinum alloy coils?
Plated coils suffer from very quick degeneration as the plating breaks down
under operating conditions. As bits of plating come off, the plug is effectively
becoming a hotter and hotter unit until in a comparatively short time it is
no longer able to perform its function. Conversely, a platinum alloy coil will
still degenerate, but as it is platinum alloy throughout, the surface remains as
platinum alloy and the plug continues giving much the same characteristics for
quite a long time.
Plated coils are very poor value when compared to platinum alloy coiled glow
plugs.
Courtesy, Warringah Radio
Control Society Incorporated
A recent magazine had
a tip by a modeler on how to protect fuel tank lines from the protruding
bolts coming through the firewall from the engine mount. His solution
was to glue in a dowel where each bolt will go, and then just tap the
dowel for the bolts. The dowels then covered up the bolts and protected
the fuel lines.
Here's a solution that may be just a bit easier! Go ahead and mount the
engine mount in your usual way, with blind nuts. The protruding bolt
ends may be "padded" by slipping on a short piece of fuel tubing over
each. ...Clay
