PROFESSIONALLY
DESIGNED BLADE PLANFORMS
FULLY
ADJUSTABLE PITCH
SIMPLE
ASSEMBLY WITH THE APEX SPEED SET (U.S. patent pending) HUB
INNOVATIVE
APEX
2, 3, 4, & 5
BLADED HUBS
- highest quality Propeller Hubs!
SUPERIOR CARBON-FIBER COMPOSITE STRUCTURE
VERY
LOW INERTIAL MASS
IDEAL FOR AIRCRAFT USING A CLUTCH
BEAUTIFUL
HIGH GLOSS FINISH
INTER-CHANGEABLE BLADES
- our construction consistency allows for easy blade replacement
EXCEPTIONAL
WARRANTY
ORDERING
POWERFIN PRODUCTS
There
are a few companies out there trying to make one blade planform work on
everything from a Rotax 277 to a Rotax 912 by trimming the diameter,
varying the pitch, or adding blades. Their propellers may be efficient on
some applications but cannot be efficient on all of them. Each type of
application requires a specific design to maximize efficiency. POWERFIN
has commissioned the services of professional aerodynamic engineers in
order to produce a number of specific designs. For instance, a Powered Parachute
requires a very specific design to maximize static thrust. The other
flight configurations of climb and cruise are basically irrelevant for
these types of vehicles. We have a propeller specifically designed for
these types of vehicles, which produces 398 pounds of static thrust on a
Rotax 582 with a 2.58 reduction ratio. That's about 50 pounds more than
the other manufacturers have produced. There won't always be that much
difference between the competition's propellers and ours but there is
always some difference due to the professional engineering of specific,
targeted designs.
The
above paragraph highlights the reasons why it is necessary to have a
specific design for your application. Even when that is done however,
there is usually some imperfection to the design. In other words, if you
were to order a fixed pitch wood prop and the person making it was the
best in the business, the variables that must be accounted for are so
numerous and uncontrollable that rarely can the propeller maker make a
blade absolutely perfect for your application. This is especially true in
the Ultralight/LSA category where small two-stroke engines can vary widely
in horsepower and torque from engine to engine of the same make and model.
The result of these variables is frequently a propeller that loads your
engine slightly too much or too little and prevents you from
throttling your engine's RPM exactly where you need, in order to use
all available horsepower. With a fixed pitch prop you are stuck with what
you have. With a fully adjustable pitch prop you can set the blades such
that you load your engine to whatever RPM you choose. This also gives you
the luxury of choosing whether you'd like to have better cruise or climb
performance - something you can't do with a fixed pitch propeller. All POWERFIN
propellers are fully pitch adjustable.
Assembling
the POWERFIN
propeller
and setting the pitch is no more difficult than putting the blades in the
Hub's bottom half, placing the Hub's top half on, putting the hardware
(bolts) in, selecting a proper feeler thickness (we give you a chart for a
starting reference), and turning the blade solidly against the feelers. We
call this our Speed Set (U.S. patent pending) Hub. The
objective of our design was to eliminate ANY requirement of finesse or
feel or ground leveling when setting the pitch. We did it and we can
proudly boast that a ham-fisted-guy can do this in high winds with his
eyes closed - and get it within a half of a degree on the first try!
Another feature of the Hubs that simplifies the setup process is the fact
that it takes only a single (Allen) wrench to do the job. There is no
fumbling or fooling around with backing nuts in this design. One wrench
and socket does the whole thing. The final feature worth noting about this
innovative Hub is that you cannot set the pitch at all if the blades are
backwards in the hub. This design precludes the possibility of many errors
that could be committed in the course of assembling and mounting a
propeller. See pictures of the assembly process here.
The
new & innovative Apex series, fully ground adjustable Hubs are the
finest crafted Hubs available to the Ultralight and LSA (Light Sport
Aircraft) markets. Made in-house on our new Haas VF4
& VF2 CNC
vertical milling station, these Hubs offer features that are unavailable
on other hubs. By nature of the fact that we own the machine, we can take
the time to pack features into our Hubs that we couldn’t afford to buy
from an outside vendor. They are highly sculpted solid 6061-T6 aluminum
and are made to the finest
CNC
machining tolerances in the industry. In fact, we specifically designed
the machining process to insure a perfectly balanced Propeller Hub. The Hubs
can be anodized to a luxurious Gold or Black finish that you will be proud
to display. It takes longer to make Apex Hubs, it’s true, but currently
no other hub rises to our Hub's quality - hence, we believe that the extra
American craftsmanship is well worth it!
The
multi-blade configurations (2, 3, 4 & 5 blade options) offered with
our Apex Hubs allow us to take advantage of the large reduction ratios
offered by Rotax and Hirth in their gearboxes. Also, more horsepower can
be loaded into more blades so this may be a solution to some applications
that have limited room to turn a propeller. See pictures of the Apex
series hubs here.
The
goal of those who design aerospace parts with carbon-fiber composite materials is to
create a part that approximates metal in strength yet remains very light.
In order to accomplish this the optimal fiber to resin ratio of the chosen
fiber must be controlled so that the published mechanical properties of
that fiber can be relied upon. If this ratio isn’t controlled, the
strength, weight, and consistency of the part will be suspect. High-tech
aerospace companies normally use PRE-PREG composite materials to
help them do this. PRE-PREG means that the fiber manufacturer lays the
resin into the fiber mechanically. The fiber to resin ratio is controlled
perfectly. It comes to our factory frozen so it will not cure. Our factory
will then cut the PRE-PREG into specific shapes and lay those shapes into
the mold cavity. With specific pressure and heat settings, the molds are
cured to produce beautifully uniform parts. The result of this level of
control is the elimination of the use of more material than is necessary
to do the job and therefore, forego useless propeller weight. Our designed
fiber placement is perfectly controlled. Fiber to resin ratio is perfectly
controlled. Void content is perfectly controlled. Weight and strength is
perfectly controlled. POWERFIN is the FIRST and ONLY propeller
manufacturer in the
USA
to make propellers for Ultralight and LSA (Light Sport Aircraft) using PRE-PREG
materials and pressure in the molding process. All the others use cruder
techniques that result in blades that are weaker or much, much heavier.
Another
aspect to our design is the high compressive strength foam core used in
our structure. The only purpose the inside of any bending structure serves
is to keep the two outside layers apart under load. Aerospace engineers
have found that high compressive strength foam can do that job without
adding much weight to the structure. One added benefit to using foam in a
high vibration environment is that it is an excellent dampener. POWERFIN
propellers use high compressive strength foam as a core material. This is
one of the reasons POWERFIN propellers have such a smooth operation and
why they have such beneficial low weight and inertial mass.
Few
things are as underrated and misunderstood about small aircraft propellers
than MOMENT-OF-INERTIA. Low moment of inertia is critical to the safe,
smooth, and long lasting operation of your two-stroke engine and reduction
unit. Inertia, by definition, is the reluctance of a mass to accept
changes in velocity. When your engine is idling the pulse tries to
accelerate the prop and the compression tries to decelerate it. High
inertial loads in this situation increase compression and hinder the
stroke causing many engines to idle poorly. Most people fiddling with
timing and fuel mixture trying to solve this problem never suspect high
MOMENT-OF-INERTIA to be the culprit. High MOMENT-OF-INERTIA in a propeller
is also bad because the propeller becomes a more effective gyroscope with
a higher tendency to remain fixed in space.
This
has three effects.
-
It
puts more pressure on the bearings in the final stages of your
reduction unit as you turn your aircraft in flight.
-
It
causes more adverse turning tendencies due to gyroscopic precession.
-
It
reflects vibration that can be felt by the pilot instead of absorbing
and dissipating it.
Low
MOMENT-OF-INERTIA in a propeller also means faster access to your
available horsepower, reducing spool-up time when you hit the throttle. In
the right flying situation a POWERFIN Propeller can pull you out of a jam
faster than a propeller with high inertia.
Low
MOMENT-OF-INERTIA in a propeller means faster spool-DOWN time, letting a CLUTCHed prop stop sooner!
Rotax
has set a limit for how much inertial mass is allowable on the B, C &
E Gearboxes. On the A/B-box they want propellers with no more than 3,000
kg/cm2. A 72" – 3-blade Ivoprop Ultralight propeller is about 4,500
kg/cm2. The same
Warp Drive
is over 10,000 kg/cm2. POWERFIN Propellers are 2,500 kg/cm2 for a big
three-blade model and 1,800 kg/cm2 for a two- blade model. POWERFIN is the
only
U.S.
manufacturer to have addressed this issue and met the challenge of
designing a very durable, low inertia propeller for the Rotax gearboxes.
The
blade finish of POWERFIN
Propellers rivals anything this industry has yet
produced. There are UV inhibitors mixed into the materials that we use so
your propeller will stay shiny for years. We also include instructions for
maintaining the finish against deterioration. Every POWERFIN blade leaves
the factory with urethane leading edge tape applied to it. This is
standard equipment and is easily replaceable if it becomes worn. The tapes
are available from POWERFIN or other aircraft suppliers at a very
reasonable cost. See
pictures of POWERFIN
blades here.
Every
aspect of POWERFIN Propellers exemplifies a precision made product. The
use of PRE-PREG carbon fiber and e-glass results in blades that are all
molded to within 5-grams total weight of each other. Due to this extremely
tight process, POWERFIN can easily match the balance of a needed
replacement blade
by referencing the number scribed onto each blade's root. This eliminates a
great deal of hassle for the customer - who already has enough to deal
with...
We
are proud of our Propeller process and the end product and hence we have structured
a warranty to prove that. So, if you purchase a POWERFIN propeller and are not
satisfied with it for ANY reason, please return it in the same condition
as it was shipped from the factory back to POWERFIN
within 30-days of purchase and we will refund your full payment. We also
offer a year warranty for free replacement of any part containing a defect
in materials or craftsmanship. Our goal is to never have a customer who is
unhappy with the POWERFIN
Propeller. Being humans of this planet, we may make mistakes at times and recommend the wrong propeller
diameter or style but we will never be complacent in the face of a
dissatisfied customer. Please let us know when you have any concern with
your purchased from POWERFIN so we can make it right.
POWERFIN
accepts both Visa and MasterCard.
Checks and
money orders will be accepted for pre-paid orders.
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