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HELP DIRECTORY -
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NOTE :
THE HELP TOPICS
The help topics consist of links and Help Topics
accumulated over the years.
Many of them were from RCM Model magazine that is now defunct.
Please review these help topics.
If we have a topic or LINK listed and you are the author and do not want
this published in this E-book,
Just notify us and it will be promptly removed.
gwhite4432@aol.com
SELECT YOUR TOPIC BELOW :
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TOPIC LISTINGS :
Laminar Flow
Laminar separation
Bubbles
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Landing Gear Tips
POLISHING
You will need the following
materials:
400 to 600 grit Wet-or-Dry Sand Paper
Emery Cloth
Twinkler Silver Polish
Aluminum "Mag Wheel" Polish
Wet sand the aluminum (sound a little strange, but this goes pretty
quickly). Keep your sanding strokes long and lengthwise along the gear.
After most of the scratches are gone, the next step is to go over the
landing gear with the Emery Cloth (don't wet sand with Emery Cloth, use it
dry!). Just as you did earlier, keep your sanding strokes long and
lengthwise along the gear. Now wipe down the gear to remove all the dust and
crud. After that, apply the Twinkle silver polish and buff. Don't try to get
the gear to shine at this point, that will come after the next step.
Go over the gear with the Emery Cloth lightly, this will bring the aluminum
to it's optimum sheen
Lastly go over the gear with the Mag Wheel Polish to protect the luster of
the aluminum.
REINFORCEMENT
What do you do if your landing gear seems to get weaker and
weaker? Just remove the gear from the airframe and remove all the hardware
from the gear wire (i.e. - the wheels, collars, pants, etc). Preheat your
kitchen oven to 450 F degrees. Place the wire on a cookie sheet in the oven
for one hour. Turn off the oven and let the gear and the oven cool down
together. Don't try to speed up the cooling process! What you have just done
is to re-temper the music wire and
you should have put new life into that old gear. Note that soldered joints
should not be harmed as solder doesn't melt until about 700 F degrees. This
tip assumes you have used a high temp solder (silver solder or other low
lead solders will melt at low temperatures and possibly leave lead deposits.
The Snap Link: These wonderful
little devices are heavily used, and rightfully so. They come in metal
solder-on, and nylon and metal screw-on forms, and can very easily be
connected or taken loose. The screw-on types, of course, provide for easy
linkage adjustment. So where's the problem? For one thing, the lead-in from
the control rod must stay pretty close to the plane of rotation of the
control or servo arm; while they rotate nicely IN their little holes, any
bending in other directions tend to make them self-disconnect. And they can
also cause binding if they are overrotated up against the servo or control
horns. The nylon types can break, the metal screw-on types can vibrate on
the threads, causing radio glitches or even thread failure.
The Snap Link with Keeper: There are
several ways to keep the snap link from being wrenched open and off, ranging
from a piece of fuel tube slipped over it to some neat little springs that
do the same thing. Perhaps the best, though, is the "golden link" which has
a metal clip that will keep the link positively closed until YOU want to
open it. For positive peace of mind, these are worth the money!
Snap Keepers: These are nylon clips that
will (hopefully) keep an L-bended wire onto its control or servo arm. They
snap on the wire on both sides of the arm, and in a low-stress installation
may be useful. NOT recommended for critical flight controls.
The Quik Link: Perhaps the easiest of
all to install, these are indeed quick - just insert into a hole in the
servo or control arm, snap on a nylon keeper, and thread thru the wire or
cable, and tighten the screw down where you want it. But these links have
some pitfalls which may cost you a plane if used on flight controls. First,
the nylon keeper "button" that holds the unit on the control or servo arm
may come off , allowing the whole thing to disconnect - this is especially
true if there is any wrenching or twisting involved. And under those
conditions, they may not want to rotate properly, causing binding. Also,
especially when used with music wire, the screw can slip. Quik Links are
quite often included as kit hardware, but a lot of careful flyers will only
use them on throttle cables, if at all.
The Ball Joint: These cost a bit more
than other links, and are quite often worth it. A ball joint has it all -
positive no slop control, no binding with moderate wrenching or twisting,
easily adjusted, and hardly any way they will disconnect themselves. In any
situation where the control arm must be free to swing in more than one
direction, this is the way to go - the connection to the servo on a strip
aileron installation is an obvious example.
NOTE: Almost all the above hardware comes in
two popular sizes - 2-56 and 4-40. These figures refer to the wire and
thread sizes involved, the 4-40 hardware being much heavier and stronger
than the 2-56 versions. The heavier gear should be used in any plane above
.60 size, and should even be considered for a fast .60, especially on
aileron and elevator control systems.
Landing Gear
Engineering - - Where, when and how to beef up
the gear.
Toe-In
- Help your plane track straight.
Case for
Camber
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Linkage Topics
LINKS
Of all the considerable number of little items that cause us problems flying
RC, one has continued to stay with us - the link between our control rods
and the control horn or servo arm. Despite constant upgrading in the
hardware available to us, despite the considerable number of new items in
the hobby shop, we still have linkage failures now and then. We may be lucky
- only a disconnected throttle - or we may lose a plane if a control link
fails.
Linkage problems can come from any one or a combination of 3 basic areas -
the hardware itself, the modelers (or designers) installation, or from wear
and tear over a number of flights. In this article, we'll look at some of
the typical types of links and examine good and not so good features of
each. See diagram.
The Z-Bend: Used right from the
inception of escapements and servos, the z-bended piece of music wire WORKS,
and has negligible chance of disconnecting. They're easy, cheap, totally
reliable. So why not use them everywhere? First, there is no way to adjust a
z-bend; you're stuck with it once installed. They're relatively hard to
connect and disconnect, they usually require drilling out the holes on
standard servo and control horns, and have a tendency to self-enlarge those
holes over time, causing slop. But they're still very useful in some
installations - an example would be the connections on an aileron bellcrank
hidden in the wing, where you can't see to inspect or get in to adjust
anyway. Here the reliability of the z-bend overshadows any other
considerations.
Drag of
Linkages with Pushrods
LINKS
- Clevis Types and Setup
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Locating Engine Mounting Holes
Engine thrust angle can be affected by small errors in
the location of the mounting holes. To ensure the mounting holes are
properly located on the engine mount, the
most important task is marking
the holes to match the engine case lugs. One good way to mark these
holes is with a machine screw of just the right size to pass through
the
hole in the mounting lug. Cut the screw so it is just a few thousandths
of and inch longer than the thickness of the lug, and, cut it on an
angle so there is a sharp
edge which extends just through the lug. Now,
use two small pieces of double sided tape to hold the engine temporarily
in place while you rotate the cutoff screw in
each of the four mounting
lug holes. This will leave a mark which is the exact diameter of, and in
the proper location for, the mounting screws.
The next part is to get a true center mark for this mounting hole. If
you have an automatic center punch, you may be aware that some of them
come with replaceable
tips. Buy an extra tip or two and grind them so
they just fit through the mounting lugs and use them to center punch the
holes.
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Log Books
Keep your flight log on your Palm. Allows you to record facts about
every flight you make with a number of aircraft on your Palm OS handheld.
By Bill Bardon.
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