Contributed by: Andrew Griffith | Published: March 2007 | Views: 238760 | Email this Article
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Review and photographs by: Andrew Griffith
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Thunder Tiger
Distributed in the US by:
Ace Hobby
26021 Commerce Center
Lake Forest CA 92630
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Low
Parts Count
Fast and Easy Construction
Stable Flying
Outstanding Parts Availability
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Tail
Rotor Hub
Clunk line deteriorates
Needs some modification for serious 3D
Manual Lacking for Beginners
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Thunder Tiger offers up the latest model in the extremely
popular Raptor line of R/C helicopters designed by Mr. Shigetada
Taya.
Mr. Taya also designed the line of Concept helicopters for
Kyosho, the model that made R/C helicopters affordable to the
masses and you didn't have to be a mechanical engineer to fly
them successfully.
This is part one
of a two part review and includes the Raptor 50 Titan built and
flown as the stock kit arrives on your doorstep. Part two
will show the installation and flight testing of several
upgrades available to increase the performance and visual appeal
of the Raptor.
I've been wanting to build a Titan since they were introduced
but the Chief of Domestic Relations where I reside has decided I
do not need another helicopter. My quandary was solved
when a flying buddy was over seas and mentioned he was ordering
one to build when he got back. Being the patriotic friend
that I am I advised him to go ahead and order it, have it
shipped to my house and I would have it ready for him when he
returned. What follows is my experience with building,
setting up and flying the Raptor 50 Titan.
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Kit
Name: Raptor 50 Titan
Price: MSRP $716.99 Street Price $420
Main Rotor Span: 1345mm (52.95") 1391 (54.75")
with 620 Blades
Flying Weight as tested: 7lbs 12oz
Blades Used: 620 mm NHP
Engine Used: OS 50SX-H Hyper
Gyro used: Futaba GY 401 w/ 9254 digital tail servo
Governor used: CSM Revlock 10
Radio equipment: JR 10x, JR 649 PCM Receiver, Hitec 5625MG
Servos,
Items
Required (more
on this later)
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Metric Allen Wrenches
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Metal Ruler with MM graduations
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Phillips or JIS screw driver.
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10 MM Socket Wrench
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Pliers
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30 Min Epoxy (If flying wood blades)
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Medium CA
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The Raptor line of helicopters go
together quickly and after building one or two you could put one
together in a matter of hours but if you take some extra care
during the assembly process you will be rewarded with as smooth
and precise a flying helicopter as many of the larger and higher
priced machines. One of the main appeals of the 50 class
of helicopters is that performance rivals that of the 60 sized
machines but with the ease of setup and parts cost of the 30
class machines and the Raptor 50 Titan is no different.
The Titan is more of a refinement to the Raptor 50 V2 than a
major new release and includes such amenities as adding
push/pull on the collective and elevator (a p/p elevator kit has
been available as an upgrade for the V2 for some time), a rear
mounted rudder servo, a longer tail boom and timing belt so the
Titan can swing 620 millimeter blades to help put the torque
produced by a modern 50 size engine to use, stainless steel
flybar and linkage rods, a beefier clutch bell with larger
bearing, and a new Titanium color on the tail boom and skids.
Thunder Tiger also added a body support for the front of the
canopy and introduced a hardened main shaft in the new kit.
The rather large box arrived on
my doorstep and appeared larger than the standard 9" x 10.5" x
28.5" box I had been expecting. Upon inspection of the
contents it became apparent that my friend had ordered enough
parts for an episode of "Pimp my Raptor" including a full metal
head, upgraded tail, skids and numerous other aluminum and
carbon parts. To be fair to those that plan on purchasing
a Raptor and assembling as they come from the factory we agreed
that this would be a two part review. This edition will
include nothing but the stock Raptor Titan as anyone would
purchase it to include the flight testing portion and a separate
review will be done detailing the installation of the upgrades
and a comparison between the flying characteristics of the stock
setup with the upgrades. |
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1. Tools Used
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2. Clunk Line with keepers
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3. Pinion bearing installed with green locktite
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Photo
1 shows the tools I have on hand. You don't necessarily "need"
all these tools but most of them make life easier and if you are
going to be at this hobby for a while decent tools are a worthwhile
investment. I'll cover the individual uses as we go along
but a quick over view of the tools I used throughout the build include
a bearing greaser, silicon dielectric grease, ball link pliers,
snap ring pliers, a delrin OS crank lock, calipers with Vario pushrod
nubs, paddle gauges, a custom made fan tool and a
Hanger 9 inline amp meter. With a clean workspace and
tools at the ready it was time to get started. Also used but
not pictured is blue and green Locktite and Tri Flow oil.
Locktite is a must for any metal to metal fasteners in any helicopter
and should be standard fare in your tool kit or field box. Tri Flow
is available in most bicycle and hardware stores and is great for
lubricating the sliding swash plate on the main shaft and the tail
pitch change slider.
The first order of business was
to read through the instruction manual which is helpfully available
from the Ace
website if you wish to browse it before your purchase or read
it covertly at work. This is one area where I find lacking
in many kits and the Raptor Titan is no exception. If you've
built a few helicopters the diagrams and notes in the manual are
fine and it will go together painlessly. If its your first
kit however there's some things that if done in the wrong order
result in some disassembly and reassemble which can be somewhat
of a chore. This is where the work of Mike Prewitt comes
in handy, Mikes website Raptor
Technique bridges the gap between a person entering the hobby
with no experience and the Thunder Tiger instruction manual.
After we get through browsing the
book its time to assemble the tank. Most of the steps in
the instructions are accomplished with a given bag of parts however
you have to have an idea what you are looking for. It would
be helpful if Thunder Tiger labeled the bags with the step number
in the instruction booklet as I have seen some other manufacturers
do. Its a small thing but would save some modeler's time
sorting through bags of parts to find the correct bag for the
step they are working on. I'm not going to try to reprint
entire manual or replace the excellent build guide on Raptor Technique,
just cover some areas I think need that special attention that
make the difference between a smooth flying helicopter and one
that has been slapped together.
The fuel tank assembly is step 1 in
the instructions and this is where I made the first deviation with
two small changes. The clunk line in many kits breaks down
quickly so while the stock line is serviceable for a few gallons it
will become brittle and collapse on itself and cause the engine to
run lean. This is mainly due to muffler pressure from high
nitro fuels and the way to combat it is to replace the stock clunk
line with a high quality line such as the Hayes line I used in photo
two. Also notice I cut 2 short sections of standard fuel line
to slip over the connection to use as a keeper, this is a nearly
bullet proof tank setup. Step 2 is the pinion and bearing
installation. The photo in the manual shows the clutch liner
being installed but this comes installed from the factory and the
beefed up clutch bell bearing is already pressed in for you.
Before putting the bearing onto the pinion I put a thin film of
green locktite (photo 3) on the pinion where the bearing will go.
Don't over do it, you don't want locktite in the bearing but you
want to make sure the inner race of the bearing is secured to the
pinion. What can happen is the pinion is made of a softer
material and the harder inner bearing race can wear away the pinion
causing play, the locktite should ensure it stays put. This is
the only instance we will use the green locktite so you can cap it
and set it aside, any reference to locktite from now on will be the
medium strength blue unless specified. Also the manual shows
locktite on the pinion where it screws into the clutch bell but its
really not needed as the engine rotation will keep it tight and
locktite will make it harder to remove later if you need to replace
the clutch bell. |
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4. Frame with stock spacers installed.
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5. Frames with after market spacers.
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6. The greaser ready to grease a bearing.
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Now its time to lay out the frame
and install the spacers. The 4 metal spacers supplied with
the kits and hex head screws surround the main shaft bearings.
This is a modification that appeared in the later runs of the V2
kits and is a nice addition. This was one of two areas
where a decision was made to go with the after market items my
friend purchased. I didn't feel the spacers would impact
the flight portion of the review and to change them for the
Maverikk machined spacer kit would have required complete
disassembly of the helicopter and frames so in went the metal
spacers (photo 5). If you are using the stock plastic spacers
and self tapping screws be sure not to use locktite, if you feel
the need you can put a drop of medium CA on the screw but I have
never found this to be needed unless you disassemble the frames
several times and then its just as easy to replace the spacers.
Another area of note during the frame assembly is that most kits
assembled overseas do not use standard phillips head screws they
use something called JIS or Japanese Industrial Standard.
A phillips screw driver will work but JIS screw drivers
available from many tool and model helicopter retailers are a
much better fit and won't strip the screw heads nearly as
easily.
Notice that the main and start
shaft bearings appear to have required a blood sacrifice (photo
5). In reality that's bearing grease and brings me to the
use of my next neat tool. This is called the bearing greaser
or "The Greaser" and is available from Petes
Hobbies and is shown in Photo 6. Simply place the bearing
in the cup and push down with the plunger and it forces grease
into the shield (Photo 7). If you are working on an existing
bearing push until the old grease is forced out and the new grease
starts to appear around the shield. This simple process
during assembly makes bearings last much longer especially if
you fly in dusty environments. After this is done to the
4 bearings install the spacers and assemble as per step 3 of the
manual.
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7. The greaser in use.
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8. Its starting to take shape.
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9. Sanding the main gear.
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It's time to put together the
autorotation bearing and main gear. One of the problems
that the Raptor has been plagued with for some time is a problem
with the auto rotation clutch occasionally locking up.
There is some steps we can take here to prevent or mitigate such
problems, doing so has resulted in my Raptors rarely locking up
an auto hub and even then its usually because I have neglected
my maintenance. The first thing to do is take the autorotation
hub (item 3 step 4) and lubricate the rollers with TriFlow.
Thunder Tiger recommends a one way bearing grease they sell and I
have never personally used it but any grease usually causes the
torrington rollers not to function correctly and I've never had
an issue with TriFlow. Before assembling the white tail drive
gear take some 220 grit sand paper to the inside as shown in
photo 9. Don't get carried away but you should be able to
take the center hub that you just lubricated and spin it
smoothly inside the tail drive gear. Now assemble as per
the instructions and if you have the small snap ring pliers I
mentioned earlier (photo 10) this will go quickly and pain free.
If you try it with needle nose pliers or hemostats I suggest one
of two methods. Put the whole thing in a large bag so when
(I didn't say IF) the snap ring goes flying it will be retained
in the bag or alternatively tie a foot long piece of
monofilament fishing line or dental floss to the snap
ring to make it easier to spot when it goes sailing away. |
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10. Snap ring installation
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11. Washout arms. (see text)
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12. Quick UK Pushrod Tool
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Step 5 shows the assembly of the
washout arms. Notice in photo 11 that there is two holes
which you can install the balls that effect the amount of pitch
change in the fly bar for a given cyclic input. The inner
hole means less throw of the paddles and makes the machine feel
more stable and the outer hole is for 3D type flying. Start
with the inner holes and once you get used to the machine give
them a try on the outer hole, you may find the helicopter is twitchy
in cyclic or pitches up or down in forward flight. Any misalignment
between the paddles or the effects of the center of gravity not
being correct will be amplified by using the outer holes, something
you should be aware of but if you follow along the CG and paddle
alignment should be correct.
Step 6 is where I ran into the
second place I wanted to install an aftermarket part to avoid
problems later on. He had purchased an upgraded elevator
A arm and rocker set so I thought I would go ahead and install
it at this time. The problem is the after market part is
quite a bit wider than the stock one because of its design and
needs to be installed when the frames are split, since I didn't
want to bother with that again, and the stock parts work fine
on my Raptors I set it aside and went to work on the rest of the
frame assembly. During the installation of the A arms another
potential problem can be avoided. Thunder Tiger links are
unidirectional and are designed to snap on the ball one way, on
the push rod linkages this is a simple matter of snapping them
on so the logo goes to the outside.
On the flybar control rods and
the A arms however there's no marking so you need to take
a moment to orient them correctly and mark the outside, I use
a silver sharpie. Set the A arm link over a ball on the
swash plate without snapping it on and take note of how much of
the ball is covered by the link, now flip it over and do it again.
One way will cover more of the ball, that is the correct way to
snap on the linkage, mark the outside and take note to build and
install the control rocker so that they snap on correctly.
The pins (item 3 step 6-1) are a friction fit in the rocker
(item 1) this would have been a nice area for Thunder Tiger to
supply C clips so do yourself a favor and take a look at the pins
prior to the first flight of the day.
During this step (or earlier if
you follow Raptor Technique) you will need to build and install
the intermediate elevator pushrod so I'm going to take this opportunity
to introduce you to more time saving tools. Out came my
Quick UK
ball link tools (photo 12 and 13) which save a LOT of wear and
tear on the finger tips and make short work of assembling the
many push rods in an R/C helicopter. I picked up some inexpensive
calipers from
Harbor Freight they have both dial and digital, I use dial
and I don't have to worry about the battery. Photo 14 and
15 show how to measure pushrods according to the manual.
You can get more expensive caliper sets but they don't really
have to be super accurate just consistent. I also purchased
the Vario pushrod tool, a set of nubs that attach to calipers
and are used to make identical pushrods, photo 16. Finish
the frame assembly in steps 6 and 7 in the manual and at this
point we are ready to put the engine together.
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13. Ball link tool at work.
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14. Pushrod measurements
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15. Setting linkage length, this works but see 16
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16. The easy accurate way
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17. OS 50SX-H Hyper
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18. Check carb is seated, aligned and tight.
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The engine to power the Raptor
Titan was an easy choice, the OS 50SX-H Hyper. Sporting
an enlarged heat sink for improved cooling and a larger throat
carb than its older brother, the venerable OS 50SX-H, the Hyper
produces more power and the new carb solves the midrange leaning
issue that some people had with the original 50. I have
found that OS engines are highly reliable, produce excellent power
and are very consistent. If you are starting out on a budget
and don't need the extra power the Thunder Tiger 50 is a good
motor and is more economical to run in terms of initial purchase
price and fuel economy. Take some time to inspect the motor
as I found the carb misalligned so check the head bolts, make
sure the carb is pressed down, the index marks align (photo 18)
and when you remove the backplate to install the fan look for
machining debris.
It came time to make another decision
in regards to after market parts installation. My friend
had ordered a CNC cooling fan and again I decided to go ahead
and install it now so a major over haul wasn't required later,
this is an amenity and the stock fan will work fine. Careful
inspection on the aftermarket fan on the left of photo 19 will
show two relieved areas for the clutch shoes, if you install a
fan with these areas there is no need to install the shim on the
clutch (photo 20), if you install the shim be sure to orient it
as shown in photo 20. Here is another area which you could
probably skip and get away with but I like to mount the clutch
and fan along with the governor magnet if you are going to use
one and balance it as a unit, mine was right on (photo 21).
You are going to have to remove the clutch to install the fan
so mark it and the fan so you put them back together the same
way.
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19. Aftermarket fan on the left, stock fan on the right.
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20. Clutch and shim.
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21. Balance fan and clutch
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There
are some differing opinions on how to properly install the fan and
prop nut on a helicopter engine but the best way I have found is
with the OS delrin crank lock tool sold for such purposes.
I would definitely NOT use the old piston lock method where a lock
is screwed into the glow plug hole, you don't want to stick anything
in the exhaust port and while removing the carb and jamming the
crank with a tooth brush works I often find that it just shears
off the tooth brush and the spouse does not appreciate her tooth
brush tasting like nitro methane (why use yours?) Photo 22
shows the crank lock tool in action, this is the way OS recommends
you install the fan as well. Set the washer that comes with
your engine aside, put some blue locktite on the threads and screw
a fan on, you can use a towel to hold on to the fan or make a simple
fan tool (photo 23) and two old bolts to snug it up, you want it
tight, any play will loosen the fan and nut during starting and
jam the clutch against the top of the bell. Put some locktite
on the threads again and install the prop nut using a socket wrench.
If you are in a hurry to go flying it might be best to do this step
first as locktite takes 24 hours or so to completely cure, failure
to do so will usually result in dropping the engine and re-tightening
the fan and nut and waiting for the locktite to dry again, do it
right the first time and let it sit over night before trying to
start the engine. |
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22. Delrin crank lock tool
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23. Fan tool
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24. Completed engine ready to install in the frames.
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When installing the engine
loosely mount the motor to the motor mount and install the
entire assembly into the main frames. Mount the motor
mount to the frame and tighten the 4 frame to mount bolts (if
you are using a remote glow wire, a good idea unless you want to
remove the canopy each start, install it now to the lower motor
mount bolt on the right side). While spinning the start
shaft backwards with your finger tighten each motor mount bolt
until you feel resistance and back off a 1/4 turn.
Continue this process until all 4 motor mount bolts are tight
and there is very little resistance in the start shaft, this
will ensure nearly perfect clutch to start shaft alignment.
While you are working the motor mount bolts be sure to align and
set the gap for the governor sensor, there should be about 1 to
2 mm clearance between the magnet and the sensor.
Its time to
assemble the rotor head. This isn't overly complicated but
there's a few things to be aware of. The first is that there is
a correct and wrong way to assemble the thrust bearings, do one
at a time so as not to mix up the bearing races. Doing this
correctly will go a long way in preventing blade woof or the
blades going out of track in a hover or maneuver. Slip both
washers over the spindle, one will rock side to side more than
the other, the one that rocks more goes towards the main rotor
hub. Something else to watch for is to orient the flybar
control rods (hoops) correctly, follow the diagram on page 12
and notice the short link goes towards the top of the rotor
head. Also remember the elevator A arms? The hoops are the
same way, sit one over a ball to determine the correct direction
to snap it on as these are also brittle and can crack if pushed
over the ball the wrong way. You also want to put some silicon
dielectric grease on the spindle (item 7 step 11) where it goes
through the rubber flap dampeners (item 9) or the rubber will
grab the spindle as it pivots and will result in nodding during
a hover and forward flight. Also put some grease on the balls
and races from the thrust bearings when you install them. I
like to run a spindle bolt in and out to make sure none of the
dampener grease is in the threads then locktite these bolts, you
will need an extra allen wrench for this step. |
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25. Ball link reaming tool
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26. Ball link reaming tool
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27. Flybar paddles need help
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Step
12 involves they flybar assembly. Care should be taken to
align and center the flybar carefully. There should be 158mm
of flybar sticking out of either side of the head assembly before
the paddles are installed. The short double links that go
from the washout arms to the main blade grip are installed during
this step and you should take care to install them the correct
direction, use your silver sharpie to mark them. Its time
to introduce another helpful tool, the ball link reamer.
Most of the ball links from the factory are fairly tight, most
of them in the head will loosen up after a few flights but the
links in the control system and A arms wont. I test fit
all the links before I install them and if needed give them a
few twists of the reamer. (Photos 25 and 26) Don't do too
much at a time, you can always take more material off, you can't
put any back on. If your links are too tight your servos will
have trouble returning to center and you will be constantly chasing
the helicopter and keeping it in trim.
When
installing the upper mast bolt make sure its snug but don't over
torque it, this bolt can break if over tightened and when that
happens the head comes off in flight, the resulting landing is
usually less than visually appealing. Screw the paddles
on until the fly bar just starts to show in the small cut out
in the paddle, install the set screws in the paddle but don't
tighten them down just yet. You can align the flybar paddles
by eye and most of the time get pretty close but a set of paddle
alignment gauges allow you to get perfect alignment every time.
As you progress in your flying and start using lighter paddles
like we will in the upgrade segment alignment becomes critical.
Photo 27 shows the use of the gauges and the paddles out of alignment,
tweak the paddles and get them perfect as photo 28 shows.
The paddles should be aligned to the head and each other.
Photo 28 shows the paddles in alignment (top of each gauge parallel
to each other) so you can tighten the set screw, just snug it
you don't want to strip the plastic and leave the gauges on so
you can verify alignment when everything is tight.
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28. Paddles ready to fly
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29. Correct orientation of tail pulley.
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30. Incorrect orientation of tail pulley.
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At
this point the helicopter should really be taking shape but its
time to give it that final piece, the tail and tail rotor assembly.
I built the Titan for its initial flight testing stock but I highly
recommend replacing the tail rotor hub and grub screw arrangement
with Thunder Tiger part number PV0499, its a one piece machined
assembly that is much more robust, the tail case and tail rotor
will be replaced in the upgrade phase of our Titan so I felt the
stock assembly would be adequate. Take care not to over
torque the grub screws (step 14 item3) as this will contribute
to early tail rotor failure. When installing the tail pitch
change fork (item 13) tighten it while spinning the slider assembly
(item 14 step 14) until you feel the bearings start to bind then
back it off 1/4 turn so the bearings run smooth, if you over tighten
this and bind the bearings they will get VERY hot in flight. Photos
29 and 30 show the red tail pulley, the edges are beveled and
it should be assembled as in photo 29, if you get this backwards
you will have 2 or 3 mm of side to side play in the tail rotor
output shaft and your gyro will always feel mushy and the tail
won't give you that "locked in" feeling.
Two
things of note while assembling the tail case, make sure the washer
for the bell crank goes between the bell crank and the tail case
I have found some binding where the builder used the washer next
to the bolt head. Be sure to keep an eye on the ball on
the pitch change slider and the bell crank, this area can pick
up a lot of grit and it acts like a lapping compound and wears
the ball down and makes for a loose fit on the bell crank, the
result will be tail kicking. Another area of note is the
belt installation. Poor tail performance can often be tracked
to the belt being twisted more than 1/4 turn. When you install
the tail boom and loop the belt over the spur gear when the main
rotor head is turned clockwise the tail rotor should turn counter
clockwise when viewing the right side of the helicopter, another
easy way to remember is if the tail rotor hits the dirt it should
always throw dirt towards the front of the helicopter. This
ensures the advancing blade is moving up and into the main rotor
wash and makes the tail rotor more efficient.
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31. Tail assembly
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32. It looks like a helicopter now!
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33. Setting up throttle linkage
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We are on the
home stretch now and its time to install and setup the servos.
I wont go into individual radio setup because everyone has their
favorite radio brand and Raptor Technique covers many popular
radios but I will give you some tips to get your mechanical setup
right. We start by choosing servos and my personal philosophy
is get good servos from the start. Some people think this
is a good place to save money but you are just cheating yourself
as you will either want to upgrade later and you end up buying
twice. Also the cost of a crash due to failed or stripped
servo will generally meet or exceed the cost of buying decent
servos to begin with. All of my Raptors use the popular
Futaba 9252 servos and these are on the high end of what required
on a 50 but they hold up very well and are fast and powerful,
I have never had a 9252 fail in flight on me.
My friend chose
to go with the Hitec 5625MG metal geared servos rated at a whopping
110oz of torque at 4.8 volts and a respectable speed of .17 for
a reasonable $55 dollars each. When servo plates are used
as supplied in the Raptor kits I leave out the brass collets especially
on the collective servo so you don't get any movement of the servos
during hard maneuvers. Also since we are using metal geared
servos don't forget to locktite the servo arm screws, ensure you
do not locktite nylon or karbonite geared servo screws because
as before, locktite will attack the plastic and make it brittle.
Photo 33 shows the how to achieve perfect pushrod length as the
numbers in the guide are close but different servos can vary those
settings. For a simple linkage like the throttle just measure
from the center of the throttle arm screw to the center of the
servo arm screw and build your pushrod to match that measurement,
the Vario pushrod nubs and a caliper make tweaking later a thing
of the past. Don't forget to size the links so everything
operates smoothly.
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34. 9254 servo drawing .11 amps, nearly stalled
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35. Tweaking the limit pot current draw comes down
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36. Max throw with minimum current draw.
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A handy tool I mentioned earlier
is the Hanger 9 inline amp meter. If you plug a servo into
one side and plug the other side into the receiver its almost
painfully simple to ensure that your control system is free of
binding. This is especially important with digital servos
as they can sap battery power at an alarming rate if the servo
is stalled. Photos 34, 35 and 36 show me adjusting the
limit pot on the 401 gyro to ensure no binding. As you can
see we started out with .1 amps, not bad but a little tweaking
and we are right in there. A stalled digital servo can
pull upwards of half and amp or more, this is especially
important when setting up the throttle linkage and the push pull
linkages.
Speaking of push pull linkages the
Titan sports push pull on all 3 major controls now including the
elevator and collective. If you prefer to use a canopy
mounted rudder servo the push pull collective assembly can be
left out, this is personal preference item. The chief
advantage of the push pull setup is the side loads on the servo
are lessened but top pilots have been flying Raptors for a long
time with a single collective rod. The chief advantage of
a canopy mounted rudder servo is less oil on the servo, less
vibration transmitted directly to the servo gear train (this is
worse with the upgraded carbon rods) and better protection in a
crash. If you choose to stick with push pull then when
building the collective push pull rods make sure you use the
short shouldered ball link ends and get the pushrod measurements
as close to perfect as you can.
According to Futaba the 401 should
be set by adjusting the linkage so that there is no drift in
rate mode, on the Raptor this is quickly accomplished by setting
the tail pitch slider so that there is 4.5 mm between the brass
slider and the tail case, in each case this has worked out
perfectly so we set the Titan there this time as well.
Our test Titan was setup for -10
and +12 degrees pitch mechanically. Normal flight mode was
set for -5 to +10 with 0 at mid stick and 1650 head speed.
Idle up 1 was enabled and set for a linear pitch curve of -10 to
+10 and a governed head speed of 2000 rpm which puts the hyper
in its happy spot of 17,000 rpm. Throttle hold was set for
-6 to +12 and we decided to revisit that later. Most
helicopters have a happy spot for doing auto rotations that
depend on blade weight, design and overall weight of the
helicopter and I have found that somewhere between -4 and -6
gets the most bang for the buck as far as maintaining blade
speed. Not enough negative pitch and you loose blade
speed, too much and it merely falls faster without increasing
the head speed. As you will see in the flight testing the
Titan autoed more like my 90 size Avant than my Raptor 50 V2. |
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It
was hard to enter the flight testing phase without any preconceived
notions as myself and Randy the owner have 10 Raptors between
us. When the weather and our work schedules finally cooperated
there were no more excuses and it was time to put her in the air.
The hyper was set to 2 1/2 turns with Cool Power 15 percent fuel
and fired up and allowed to sit at a high idle for a few minutes.
Modern engines to not need extended break ins but I knew from
prior experience with these engines they benefited from gentle
treatment for a few tanks. After the engine warmed up a
bit we did some basic hovering and the Raptor hovered just a slight
amount of right trim. This is to be expected from a clockwise
rotation main rotor and is called translating tendency and is
caused by the tail rotor blowing the helicopter to the side.
The
Raptor settled into a smooth hover but the tail was kicking and
the engine sounded very rich so we turned the needle in 4 clicks
and the hyper started to smooth out. A few tanks of hovering
and flying circuits and the backplate was getting cooler to the
touch indicating the ring was seating and the engine was breaking
in nicely. After we had the top end setting close we performed
the pinch test and had to lean the low end slightly to get 4 seconds
of smooth idle before the motor started to speed up.
With engine break in and trimming completed we put the Raptor
through its paces. We found the Titan to be very stable
but a bit slow in cyclic response. This was to be expected
with the heavier black paddles, soft blue dampeners and longer
blades. Tail performance even with the stock tail blades was
fast and crisp. Auto rotations were smooth and predictable
with plenty of energy at the bottom to enter a hover and land.
When the local expert Wayne Clarke flew the Titan he landed,
took off, did a piro and landed all in throttle hold, very nice!
While the longer blades and heavy paddles detract from the 3D
performance they make a very stable training platform and should
serve anyone from a beginner to intermediate flyer very well.
Hirobo paddles are weighted and as you progress you simply
remove the weights and adjust the linkages and that is why in
misses I've listed that you need to upgrade some components for
serious stick banging such as paddles, dampeners and a metal
head block (optional but the plastic head block can wear quickly
at higher head speeds).
See
the Raptor 50 Titan in action!

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Thunder Tiger has another winner
on their hands. The Titan continues the successful pedigree
of the Raptor line and its enhancements though subtle are worthwhile
especially the ability to swing 620 mm blades as it lets the pilot
put more of the torque of the 50 Hyper engine to the blades.
Even in the stock form the Titan easily performed loops, rolls,
upright and inverted funnels, elevator and aileron tic-tocs with
ease and grace. It was very stable in the hover and will take
a beginner pilot from basic training through intermediate 3D in
a moderately priced package that is easy to assemble and maintain.
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Thunder Tiger Titan
Retail and Sold in the US by:

HeliProz.com
Phone:(877)
435-4776
Thunder Tiger
Distributed in the US by:
Ace Hobby
26021 Commercecentre
Lake Forest CA 92630
Phone:(949)
833-0088
Futaba & OS
Distributed in North America by
Great Planes Model
Distributors
P.O. Box 9021
Champaign, IL 61826-9021
Website:
http://www.futabarc.com
http://www.osengines.com
Products used: OS 50SX-H Hyper Futaba
GY-401, Futaba 9254 Servo
CSM
Distributed in the US by
Advantage Hobby
PO Box 6988
Champaign, IL 61826 USA
Phone:
(217 867-2300
Web Site: http://www.advantagehobby.com
E-mail: ihelp@advantagehobby.com
product used: CSM Revlock 10
Hitec
Hitec RCD USA, Inc.
12115 Paine St.
Poway CA, 92064
Phone: 858.748.6948
Website
http://www.hitecrcd.com
Product used: 5625MG Servos
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The comments, observations and conclusions made in this review are solely with respect to the particular item the editor reviewed and may not apply generally to similar products by the manufacturer. We cannot be responsible for any manufacturer defects in workmanship or other deficiencies in products like the one featured in the review. |
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