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Below are ideas and products I've used that are
especially creative or useful and thus might be noteworthy to other RV-8
builders and pilots.
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IDEA:
Navaid installation
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I agonized for months about where to
put the Navaid servo and associated hardware. Most builders locate them
under the rear passenger footwells which is really under the pilot's seat.
This is logical and would work well but doesn't provide for easy access when
making adjustments or troubleshooting the servo. Since the servo is a
mechanical widget with lots of gears and electronics it just made sense to
me that I'd need to get at fairly frequently. Accessing the floor area is a
real hassle: you must remove about 30 screws, the crotchbelt which is cotter
keyed, the seat back, and the front floor assembly. While agonizing I
stumbled across RV-8 builder Ray Lynn's installation... forward of the main
spar carry-through. (http://vondane.com/rv8a/tt&i/index.htm#navaid)
Nope, I can't take credit for this concept. With the
servo located forward of the F-804 main spar you can get it after just
removing the right cabin console cover. BTW, if you use this technique make
sure you trim the console cover so that it does not mount under that little
triangular right front seat pan bracket. I manufactured the servo mount from
scrap pieces of .063" aluminum and .063" angle — very handy
stuff. The servo much be raised a bit so clear the screws on the bottom, so
I included mounting rails on each end to raise it up. Note that one vertical
side must be shorter than the other to compensate for the lower longeron
it's mounted to. Since you can't get in there to buck driven rivets, the two
vertical sides are attached to the floor with blind rivets. I used Pop
rivets on the inboard side and CherryMax on the outboard side. The only
reason I used the CherryMax is that I need a longer reach to go through the
longeron and the Pop rivets I had on hand did not have enough grip range. I
attached the control rod to the main control yoke with a special piece my
buddy Randy Griffin made from stainless steel. you could easily make one
from 1/8" aluminum though.
In all this installation works
very well. I was able to quickly do the set-up adjustments, which require
access to the inside of the box, while sitting in the pilot's seat. If I
ever need to go back in it's only six screws away. BTW, if you're
considering NOT installing the Navaid I highly suggest you reconsider. For
$1,450 you get a single axis autopilot that will track whatever signal
you feed it (VOR, GPS, Loran), a wing leveler, and a turn coordinator. The
first time you set a course in your GPS, push the Smart Coupler to
"course" and get the green LED, and feel the Navaid lock in on the
course you will think it's magic. It will even make the turns for you at
your waypoints!
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IDEA:
Baggage Door Prop
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After contemplating how to solve a
relatively easy problem (how to keep the darn baggage door open) for at
least six months, I finally came up with something I'm happy with. Actually
RV-8 builder Jeff Ludwig gets credit for it. When I saw it on his plane I
immediately said "that's it!". It's
simply a "door prop" purchased from Lowe's for $1.97. I bought it
while on a business trip and didn't know if I'd find them again so I bought
three and gave two of them to Jeff and Randy, my builder buddies. The upper
end is blind riveted into the door and the bottom pivots on a bolt that was
already there to mount the LASAR brain on the firewall. I replaced the AN
bolt with a hardware store cad-plated grade 8 and used a nylok nut to let it
hinge freely. The nylon washers are just there for good measure. With the
center locking detent this thing works great! If you try it for your plane
be careful of the geometry. It is possible to locate in a way that will
prevent the baggage door from closing. As with anything else in building
these planes, measure twice, drill once.
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IDEA: Improved cabin heat system |
RV-8s are very comfortable for the person in the back seat. Having flown
back there for five hours during my checkout I think it is actually more
comfortable than the front seat (although I still prefer the front!). One
bad thing about the back though is that it can be very cold. I don't have
the problem of air coming in from the back of the canopy and hitting the
back of the passenger's neck, but there are other factors contributing to a
cold back seat. Van's plans call for the cabin heat to penetrate the
firewall and then just blast the pilot's feet from wherever you choose to
make that firewall penetration. While flying the pilot's lower extremities
will be warm, but his/her torso will be relatively cool, and the passenger
will be completely unheated. Thus began the thought process for improvement.
Improved cabin heat distribution has been
considered by many builders improved by few. The primary reason for this is
that to duct warm air to the rear one needs to penetrate both the gear
towers and the main wing spar carrythrough with at least a 2" hole. Since
both of these assemblies are structural, Van's has specifically advised
against this type of penetration. Still, there had to be something better
than simply dumping the heat out of the firewall.
I began my improvement by having an aluminum
elbow made that could be mounted to a 2" ducted flange that I had riveted to
my heat box. My heat box was first modified by moving the actuator arm from
the inside to the outside, easily done by drilling out a few rivets. I then
routed the cable through a firewall eyeball and fabricated a standoff to
give the cable proper geometry. The 2" ducted flange was riveted to the box
and the box was re-installed. The elbow (seen in the pic) was then secured
with a simple screw to the duct.
I then used 2" scat tubing to bring the air
back near the gear tower area. I flew several times experimenting with the
exit point by simply using zip ties to secure the scat. In the end I found
that terminating the scat with a standard Van's plastic eyeball vent on the
front corner of the gear tower gave me the most flexibility in directing the
air: it was far enough back to direct a blast of warm air down the left side
of the pilot into the passenger's torso area. It was also far enough forward
to redirect toward the pilot when there was no rear seat occupant.
This improvement works well: it blows air
down the left side into passenger torso area, or can be directed via the
ball vent toward pilot's torso. When solo I've found it is still better to
leave it blowing down the side though to warm the cabin more evenly. I'm
using one standard Robbins heat muff which seems to be adequate for this
part of the country. It will provide heat down to about 25 degrees, below
that it's more like lukewarm air.
Even with this improvement there is one
remaining problem: the passenger's feet. Consistently my passengers report
that even with the nice warm air blast their feel get quite cold from being
down in the footwells beside the pilot. At this point I am still advising an
extra pair of socks for winter use, any better ideas would be welcomed.
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IDEA: Rudder Pedal Extensions |

The RV-8 uses a different rudder
pedal system than any other RV model and it has an inherent problem with the
geometry. Due to the relationship of the pedal pivots to where the pilot
applies any pressure to the pedal, it is impossible to apply any rudder
without also applying at least a small amount of brake. Even if you just
push your toes on the small flat section at the bottom of the pedal you will
notice brakes being applied, whether taxiing or during your landing rollout.
I noticed this phenomena and while scratching my head trying to come up with
a solution fellow RV-8 builder Jeff Jasinsky designed these rudder pedal
extensions for his not yet flying plane. I shamelessly copied his design and
put them to the test... they work perfectly! They are made from .125"
aluminum, bent in a vice to around 40° and attached to the rudder pedals
with #8 countersunk screws. (All parts were re-painted black before
installation) You use them in two different ways: when taxiing where no
brakes will be needed you put the ball of your foot in the pocket created by
the extension and the bottom of the pedal. Because the center of pressure is
now below the pivot the pedal is tilted back thus pulling the master
cylinder instead of pushing on it and applying brakes. When landing you can
put the balls of your feet in the normal place and your heels naturally rest
on the extensions. By pushing with your heels this lets you make rudder
inputs with no brakes yet have your feet on the pedals where you can make a
quick stab at the brake should things get squirrelly in that crosswind
landing rollout. Feel free to copy, thanks to Jeff!
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IDEA: Tailwheel dragger |
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Having owned a Cessna I had an extra
152/172 tow bar laying around from when I sold my 150. Gee, it just happens
to fit over the bolt and nut of the tailwheel of my RV-8, great! While I
don't carry it around with me in the interest of not increasing weight, I
use it every time I pull the plane into or out of the hangar. The bar in the
picture is a "Bogy Bar" but any tow bar designed for the nosewheel of a
small Cessna should work.
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PRODUCT:
Meyer Aviation Headsets
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Through
a friend I found out about a guy in Michigan that takes David Clark
headphone parts and assembles them into a unique headset solution. If you're
looking for a true linear frequency response high-fidelity headset, and
one that also
provides the most passive noise reduction available, then look no further. John
Meyer (Meyer Aviation) can offer you two paths. First, he can take your standard David Clark's and convert them
to true hi-fi by replacing the drivers. For this he charges $50 for mono
sets and $75 for stereo sets. But the real treat is the second option: get a
set of his custom headsets. His specialty is to begin with David Clark's
H10-56 helicopter cups and frame, and build up the best
in every respect. What most folks don't
realize is that the DC helicopter headsets begin with a larger (and heavier)
headset cup with more sound absorbing insulation. Regular DC models, with
the gel seals, provide 23 db of passive noise reduction whereas the helicopter
models provide 27. Now that may not sound like much but remember that sound
pressure levels require a doubling of energy for a 3 db increase. Or
conversely, for a 3 db reduction you need to cut the acoustic energy in
half. Anyway, the custom headsets feature the helicopter cups, his
high-fidelity drivers, his own electret mic element (the standard H10-56s
have a dynamic mic), and all the usual comfort goodies such as the gel
seals. For this he charges around $300, a bargain in my opinion. These are the best headsets I've ever used. Not only do they come
close to comparing to home hi-fi headphones fidelity-wise, but I don't even notice the
extra weight. And the extra quiet provided by the superior passive noise
reduction is immediately apparent — just put them on and you'll notice it
right away. I recently installed a PS Engineering PCD7100 intercom with CD
player and the fidelity is fabulous. There really is no comparable product
available, all the current offerings from Lightspeed for example do not have
true linear frequency response. Check the specs for the frequency response
of their drivers and you'll see it's rolled off in the bottom and top ends
to optimize voice reproduction - not what you want for high fidelity
reproduction. David Clark's normal products do the same thing.
By the way, if you call David Clark
and talk to any of the product managers they are fully aware of John and
what he is doing. Actually they unofficially refer people to him and
recommend his solution for those interested in what he has to offer. See his web site for further info...
www.dipple.com/jmeyer
or call him at 616-896-9858.
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PRODUCT: King
Antenna Adapter
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Many of us carry a handheld com radio as a backup
in case our electrical system goes down or our com goes out. What most
pilots don't have however is a way to quickly and easily get access to their
external antenna. The rubber ducky antenna on most handheld coms just
doesn't provide much range for either send or receive. Simply coupling it to
an external antenna will let it perform nearly as well as your in-panel
unit. In designing my electrical system, and searching for a way to quickly
and easily access my belly mounted com antenna, I started asking questions.
One obvious strategy is to install a simple antenna cable splitter. Then, in
the event of a panel com failure, just connect a piece of coax cable with
BNC connectors both the the splitter box and the antenna connector on the
radio. The problem with this however is that whenever you split an
electrical signal you lose 3 db which is 50% of the power/energy. This loss
would be present all of the time whether the handheld was connected or not.
Hmm, not good. In spite of poring over all the avionics supply catalogs I
just could not come up with a better solution.
When the time came to buy my
avionics I asked Dewey at Pacific Coast Avionics what the best solution was.
He said "Oh, you need a King KX-99 antenna adapter". Okay. Turns
out it's a little box that interrupts
the antenna cable whenever a plug is inserted and connects your
handheld. Perfect! This little device, while not cheap at around $75,
is a little box and a special cable. The small lightweight cable has a
1/8" mini-plug on one end, which goes into the box, and a BNC on the
other that connects to your handheld unit. When the mini-plug is inserted it
disconnects the main com radio and connects the handheld... voila, no signal
loss. All you need to do is mount this in a reachable location while in
flight and keep your handheld radio and the special cord within reach. Note
the part number on the picture and just order it from your local avionics
supplier. Thanks Dewey!
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PRODUCT:
Aircraft Spruce A-600 Brake Reservoirs
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Normally
RV-8 brake master cylinders are supplied fluid from an aluminum reservoir
mounted on the firewall, which feeds fluid through plastic low-pressure
line. This low-pressure system leaks terribly. I had to fool with mine three
times, re-purging the system of air each time... a horribly messy task.
Fellow RV-8 builder Randy Griffin then discovered these in the Aircraft
Spruce catalog. They have an NPT fitting that screws right into the master
cylinders. Voila, no more leaks, less tubing hanging around... a clean and
simple solution that I highly recommend.
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PRODUCT:
Skybolt cowl fasteners
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Although
I've covered this fairly thoroughly on the Cowl page, I wanted to mention
Skybolt's cowl fasteners here because they really do work well. Using them
for your entire firewall perimeter with Van's hinge on the horizontal
parting line is what I ended up with as the best of both and highly
recommend it. Several other RV builders have taken this advice and are
unanimously glad they did. See the Cowl
& plenum page for more info.
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PRODUCT: RV/Rocket
Steering Link |
For
the first hundred hours or so I flew my plane I heard this constant rattling
while taxiing coming from the aft end of the plane. I figured it was the
"screen door chain" tailwheel steering link that Van's provides but didn't
know for sure. Finally, after the winter moisture started rusting my springs
& chains, I ordered one of Terry Jantzi's Steering Link. As you can see in
the pics it's a much more elegant solution... lighter, aerodynamically
cleaner, and infinitely tricker. No more rattling or rust either. It does
steer quicker but you get used to it very quickly. To order yours go to...
www.iwantarocket.com |
PRODUCT: Tail-Mate |
Here's something I saw an ad for
while thumbing through an aviation magazine that I use all the time... the
Tail-Mate. It slides right under the tailwheel and let's you jack the plane
all the way up to flight attitude in seconds. You don't even need to pick up
the tailwheel, just give it a sharp shove as long as your mainwheels are
chocked and it slides right in, then jack it up to clean your belly or bring
the nose down to more easily work on your engine. Sometimes you need the
plane in flight attitude to make some adjustment, no problem. I really wish
I had had this thing while I was building, but I still use it continually as
it is... a must have! Check it out at...
www.tail-mate.com
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PRODUCT: Aero
Assembly Automation front stick |
Those
of you who have piloted an RV-8 know that the ergonomics of the front stick
are a bit wanting — the stick is too far forward and too low. RV-8 builder
Todd Rudberg has attempted to solve the problem by putting some strategic
bends in the standard stick. (bends in the pic have since been changed a
bit)Installation of the stick requires
a small adjustment of the rod end bearing in order for it to not contact the
front edge of the seat pan when pulled full aft. The bends in the stick
provide for 1.5" of setback of which probably .5" is given back in
adjustments. Still, it puts the handle about 1.0" aft of it's original
position. In my case I also left the stick as long as possible so that as it
goes under the panel the PTT button barely clears. (unless you have inverted
fuel and oil systems you will never use that much forward stick deflection)
In all, while a small improvement, it has improved the pilot's ergonomics.
Todd has come up with several good idea products
for the RV-8 so you might want to check his web site...
www.rvwoody.com.
If I were building my plane again I would definitely use his modular panel!
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