Here is a series of modifications and upgrades that can be done to the Raptor. Some will give benefits others are just for looks. It is up to the user to determine the aceptability and consequenses of installing any of the below mentioned items. Listed are the reasons for the upgrade/mod and the cost.
46/50 Engine
The quest for power is neverending. So there are engine mounts and fans available
to install an OS46FXH, OS50SXH or any equivalent sized engine. There is a
substantial increase in power and a subsequent decrease in flying time because of the small fueltank. More
power also places heli components at higher stress resulting in a shorter
lifespan. The stock blades are not big enough for the 46 power. Even with maximum pitch of +/- 10 deg the engine may overspeed. Some pilots run max throttle of 80% and add cyclic to throttle mixing for additional power during manouvers. A longer boom
and belt will allow the installation of 600mm blades, ideal for the 46. Maximum
blade length with the stock boom is 560mm. The OS46FXH also suffers from a
inferior carburator that causes engine rpm surges during low pitch conditions. This is also refered to as the 'wah wahs' for the sound the engine makes.
OS46 / OS50 / Other 46 U$ 100.00 to U$ 200.00
Muffler for the bigger engine - see muffler section
Long boom and belt U$ 40.00
600mm blades U$ 50.00 to U$ 150.00
Engine mount and Fan U$ 50.00
TT Muffler Baffle installation.
The factory muffler has no internal baffles and provides minimal pressure
to the fuel tank. Open the muffler by unscrewing the long bolt. Take a 3/4
in diameter washer and install it with two 3 mm lock nuts on the long bolt
aft of the pressure fitting. Reassemble muffler. Lean the main needle about
1/2 turn to compensate for the additional pressure.
You will need a bigass washer and some 3mm nuts. About U$ 2.00
Century 3033A Muffler
This is Centurys' 46 size CN3033A muffler. Made for 46 engines it's bigger
size gives the 30 size engines more room to breathe. It requires a small mod
to one of the screw holes to line up the screws coming out of the 30 size
engines. Since it's the same cost as the CN3033 30 size muffler going bigger
is free. Other excellent mufflers are the KSJ, ARK and Hatori.
Century Helicopter World U$ 40.00
KSJ30 or 46 U$ 85.00 to U$ 95.00
ARK30 or 46 U$ 45.00 to U$ 65.00
Hatori 30 or 46 U$ 100.00 to U$ 140.00
Clutch Modification
There have been many reports of early clutch failure with the Raptor. One
of the cause is the excessive clutch to clutch liner gap which causes the
clutch arms to spring out to far, fatiqueing the metal and finally breaking
it at the flex point. The fix is to glue thin cardstock like a business card
between the liner and the bell. The clutch should just slightly drag at idle
when first installed. After a gallon or so the wear will make the gap perfect.
Other causes are inaccurate engine/clutch/clutchbell/startshaft alignment.
Slightly opening up the holes in the frame for the engine mount screws will
allow the engine/mount/clutch package to be positioned for optimum alignment.
The clutch itself has a design flaw. The clutch shoes that move out due to
centrifucal force to engage the line may hang up on top of the fan hub. Filing
away the section under the shoes or installing a shim between the clutch and
fanhub will provide adequate clearance. (see pics).
Clutch liners U$ 7.00
Business card U$ free
Fan hub/clutch shim U$ 6.00
Tail Boom servo mount
A lot of pilots prefer to mount the tailrotor servo on the boom to eliminate
the long pushrod. It also eliminates the need for a servo extension if the
Gyro os mounted behing the mainshaft (as in the pictures). Several kits are
available. The cheap version shown utilizes the cut down original wire pushrod.
The fancy ones include a carbon fiber pushrod.
KSJ Servo tailboom mount U$ 15.00
NHP Servo tailboom mount with pushrod U$ 35.00
KSJ flybar paddles
For high cyclic rates as used in extreme aerobatics the stock black flybar
paddles are too heavy. KSJ makes a set just extreme applications. Comes in
pink or yellow. For some pilots the aggressive paddles cause pitch control
problems in forward flight. For a bit tamer response cut off 1/8 to 1/4 (3
to 5mm) of the sharp leading edge of the paddle and round off the cut. A little
weight like the old wheelcollars as shown in the picture will increase stability
in hover.
KSJ Paddles U$ 10.00
ATS Carbon mainblades
The stock wooden blades supplied with the kit are excellent for most flight
regimes. For better aerobatics and autorotations carbon fiber blades are avialable.
There are many manufacturers and a variety of blade lengths, weights and airfoils.
The ATS 550 blades shown are semisymmetrical making for excellent upright
and autorotation performance. They are not recommended for inverted flight.
ATS Carbon 550 semi U$ 65.00
Vic's Blades 550 sym U$ 100.00
Century Hurrican 550 sym or semi U$ 85
NHP carbon 550 sym U$ 80.
KSJ Tailblades
The stock tailblades are adequate but the KSJ's are an inexpensive upgrade.
They come in hot pink or screaming yellow.
KSJ tailblades U$ 9.00
Header Tank
A header tank is nothing more than a bubbletrap. During hard aerobatics the
clunk in the maintank may suck air momentarily. The airbubble is trapped in
the header tank where fuel is picked up in the center of the tank away from
the air. The Header tank will NOT affect the mixture and it's location relative
to the carburator is unimportant. It is a fat piece of fuelline. Only when
the main tank is empty and fuel is drawn soley from the header will the mixture
change. A good indicator to land and refuel.
Hayes 2oz tank and brass mounting strap U$ 8.00
T&T 2oz header tank with metal stopper U$ 30.00
Voltage Monitor
This is a vital piece of equipment that no heli or airplane should be without.
This one is taped to the header tank. The LEDs indicate present battery voltage.
Indicators are available for 4.8 and 6V systems. Another version, the BC-6
Glitch Counter, records the lowest voltage that occured during flight and
any radio interference the radio received. This is extremely important with
a PCM receiver that can mask small interference glitches.
Voltwatch U$ 15.00
BC-6 Glitch Counter and Battery Monitor U$ 40.00
Cooling Shroud extension
The molded in cooling shroud is fairly adequate for most needs and the extra
size is convenient when installing the big 46 size engines. However when a
30 size motor is installed, the is a large gap around the engine head cooling
fins. The airflow from the fan will seek the path of least resistance and
flow around the fins and the engine may overheat. This is particularly true
when the ambient air temperature exceeds 90 deg F like in most southern states.
It is simple to fashion a 1/2 inch (10mm) piece of balsawood, fuelproof it
with thin CA and then use Goop or CA to glue it to ONE SIDE of the frame inside
the cooling duct. The glowplug has to be removed for this so the wood can
slide up close to the cooling fins. Mark the location of the glowplug and
cut a 1/2 inch (10mm) hole to insert the glowplug after the wood has been
glued to the frame.
Balsa wood scrap U$ 1.00