Lots
of high quality aluminum and red anodized parts.
Improved clutch and new beefier tail rotor hub.
Carbon stacked frames and torque tube drive tail rotor.
While very attractive, the canopy is hard to see on all but
bright sunny days.
Servo installation sequence in manual isn't optimal.
Replacement frame cost. (note that the canopy break away
pieces are designed to prevent damage to the frames in all but
the worst crashes)
JR
Helicopters has released their NEXt generation 50 size nitro
helicopter; the Vibe 50NEX.
In
June of 2008 I had the pleasure of building and reviewing the
original
JR Vibe 50 for RCUniverse and was impressed with both the
design and flying qualities of the new (at the time) kit.
At the time it was hard to find fault with the kit but as with
anything, over time some weaknesses were uncovered.
The tail rotor hub was easy to bend and the stock tail blades
weren't very robust. Of course, these issues took some
time to uncover but overall the Vibe 50 has been the most
reliable and solid performer I have owned over the years.
The NEX 50 however, has taken high quality and attention to
detail to a new level for 50 size helicopters. It's much
more like a shrunken down version of the 90SG (Scott Gray
design) than an evolution of the original Vibe. It sports
a new look with carbon fiber frames, a red and black painted fiberglass canopy, and
many red anodized aluminum parts that really make the NEX stand
out.
There are a lot of choices in the 50 size helicopter class so
lets get started and find out how the Vibe 50 NEX stacks up
against the competition.
Kit Name:
JR Vibe 50 NEX Price: $559.99 Main Rotor Span: 53.58" (1361mm)*
with 600mm blades Flying Weight as tested: 7lbs
12oz (3.4Kg) Engine Used: OS 50 Hyper w/
Hatori 522 Blades Used: RotorTech 610mm Battery used: 2S 2500Mah Voltz
LiPo Radio equipment used: JR 11X 2.4 Ghz, AR7100R
receiver, JR 8717 Servos on cyclic, JR 8311
servo on throttle, a JR G370 Gyro and MP-80G
brushless tail servo.
6 Channel (minimum) radio system with CCPM Helicopter mixing
and 4 servos.
Tail Gyro and servo
Receiver battery
50 class nitro engine and muffler
Glow plug extension
600mm main rotor blades
Nitro
starting equipment and 6mm start shaft
Thread locker, medium fuel line, and epoxy
Metric allen drivers or wrenches
JIS (better) or phillips screw drivers
Pitch gauge and swash plate leveling tool
Metric ruler
New arrival
Neat new logo
Nicely protected contents
My beloved Vibe 50 had met an
unfortunate and untimely demise so I was already looking for a
replacement when the Vibe 50 NEX came on the market. I
always knew that if something happened to it the question of
getting another Vibe wouldn't be a matter of if but when.
Once I received the Vibe 50 NEX though, I was glad I waited.
The brown aircraft delivery
vehicle left the Vibe at my front door intact and free of any
apparent shipping damage. About the only thing in a
helicopter kit that would readily be susceptible to rough
handling would be the fiberglass canopy and that was wrapped in
a protective material, bagged, and secured with packing paper.
All of the rest of the parts were in sealed bags and numbered to
match the steps in the instruction manual. There was no
hint of damage anywhere.
I opened things up, gave
everything a cursory inspection, retrieved the instruction manual and got
comfortable for some reading before I opened a single bag.
If you've ever built a helicopter kit from the ground up,
building the Vibe is straightforward. The manual assumes
some familiarity with building practices so the assembly instructions do not contain a
lot of spoon feeding. Be sure to read all the notes on
each step before doing any work; some things seem out of
sequence but everything comes together during final assembly.
This is especially true when it comes to fully tightening and applying thread locker
to the frame and engine mount bolts.
There are lots of line drawings
showing where things go with building notes for each step.
Also all of the hardware needed for a particular step is shown
in actual size. The radio installation and setup area of
the manual is both well written and comprehensive. I've
seen manuals with more step by step directions but if you study
the drawings and follow the notes for each step, you won't have
any problems building the NEX even if its your first nitro
helicopter.
SIMILARITIES
Like its older
brother, the NEX is a stacked frame design that uses a bearing
supported aluminum torque
tube driven tail for maximum tail authority. Once set
up, the torque
tube tail needs no adjustment and has incredibly little drag for
maximum power transfer and
plenty of hang time during auto rotations. The main rotor head design
with the grip mounted mixing levers is also maintained. I
said in my previous review that the bearing blocks, swash, and
auto clutch wouldn't look out of place in a jewelry case and the NEX maintains that high quality while adding attractive looking
red anodized parts such as the swash, upper mixing arms, and
tail case parts.
The Vibe 50 NEX
contains all of the parts so you can assemble it using either
120 degree CCPM or the interaction free 140 degree CCPM (see
previous build article for full explanation of the
differences). In short, if your radio supports it, use
140, but if not don't bother with trying to work out the mixing,
we have both and its really hard to feel any significant
difference in the air.
The frame mounted
governor sensor is maintained in the new version as is the
vibration isolated fuel tank and intermediate bell crank rudder
pushrod. All connections to the swashplate are push/pull
through ball bearing supported bell cranks. When assembled
the control system is smooth as butter.
New clutch (R)
New tail hub (R)
Carbon side frames
DIFFERENCES
The differences we
noted were mostly refinements. The first thing that really
stands out is that all of the G10 fiberglass is gone. The NEX
sports 2mm thick carbon fiber main frames, fins, and a bottom
frame plate. Not only is it better looking, it seems quite
a bit stiffer as well. In addition, there are carbon side frame
stiffeners mounted inline with the clutch bell that make it look
like a smaller version of the 90SG. This should all add up
to a minimum of frame flex during even the most violent 3D
flying. The break away mounts for the canopy posts should
minimize damage to the carbon frames, I broke the ones of my
original Vibe 50 several times without damaging the G10 main frames.
The plastic main blade
grips have been replaced by machined black metal grips
that look quite stout. Gone though is the recessed area
for the nut so you need a driver and a wrench to change the
blades or remove the blade bolts. The NEX blade grip
assembly moves the thrust bearings to the outside of the radial
bearings.
The flybar paddles
included with the V50 were a somewhat conservative thickness and
included removable weights to adjust head responsiveness.
Most everyone I know removed the weights or replaced the paddles
with ultra light carbons. By comparison the NEX paddles
appear rather aggressive with a thin airfoil, sharp leading
edge, and no weight. I'm looking forward to trying these!
The collet style
fan mount which can be a bit of a nuisance and requires a fan
puller to remove has been banished from the NEX. The red
machined fan hub, which seems almost a shame to hide under a
cooling shroud, threads directly on to the engine crank shaft. The
start shaft is also larger and a bigger one way bearing occupies
the center of the new clutch.
At the rear of the
helicopter the metal tail case is beefed up and the tail output
shaft bearings are better supported. Also the tail rotor
hub is thicker and and less prone to "tweaking" on marginal
landings. As with the original Vibe, the tail rotor hub
design appears borrowed from its larger cousin so the tail disk
is quite large and blades in the 85 to 92 range are recommended.
In the little
details department the tail pushrod guides split so you can
remove them without pulling the boom. The old design had
that idea but there were teeth on them that would wear out,
these look better. The ball links also look similar but
feel completely different. Not once while building two
kits at the same time did we need to reach for the ball link
reamer. The links are a bit difficult to snap on or
remove, but once snapped on they seem perfectly sized with no
play or drag.
Last, they
advertise that the parts count is lower and while we didn't
count every screw and washer, the molded plastic radio mounting
tray alone easily saved over a dozen parts and twice that many
screws.
A TALE OF TWO
VIBES
Inspired by my
success with the original Vibe 50 my flying buddy, often
un-credited review helper, and room mate Frank Foti
bought his own V50. After having flew a few other designs,
his pattern flying background really meshed well with the smooth
flying Vibe. Inspired by the crash and near total
destruction of my V50 he totaled his about a week later as well.
So when the review kit arrived he looked mine over and placed
one on order for himself.
This affords us
the unique opportunity to build and fly two of these side by
side, one equipped with 140 degree CCPM and the other with a 120
degree setup. Mine is going to be guided by a JR 11X
linked to an AR7100R receiver and equipped with 8717 servos.
Franks radio duties are handled by a DX7/AR7000 combo. In
the flight shots, mine has the stock canopy while Franks is
adorned with the distinctive and brightly colored Canomod canopy. Powering both
models are OS-50Hyper engines with Hatori 522 mufflers.
Enough comparisons
already, the new kits are here so let's get started!
Numbered bags match manual
Canopy, stickers, and manual
Clutch bell and start shaft
Tail drive assembly
140 CCPM bellcrank assembly
Main gear and auto hub
Before you get started things will go much smoother if you have
everything you need handy when the instructions call for it. One of the
important things to note before getting started is that JR
labels their thread locking agent somewhat differently than what
we consider the norm. If you're not using JR's thread
locker than keep the following in mind. The icon's that
show "red" thread lock are medium strength or what is
commonly referred to as blue, and where they indicate "green"
that is what helicopter folks normally associate with red high
strength (takes heat to remove) thread locker.
There are a number of tools that we have for assembling and
maintaining model helicopters that can be split in to two
categories; essential, and nice to have.
In the essentials you should have a set of metric allen wrenches
or drivers (hardened type drivers work best), and a set of open
end metric wrenches. Phillips or even better, JIS screw
drivers, a metric ruler, pitch gauge, and ball link pliers all
will get regular use.
If you're going to stick with it, a dial or digital caliper and
Vario
pushrod tool, paddle gauges, a bearing greaser such as "The
Greaser", and a
Hanger 9 Inline Amp Meter will all be welcome additions to
your tool inventory. If you really become serious a dial
indicator and magnet base will become a fixture in your
workshop.
The first decision you have to make is whether you're going to
build your NEX with 120 or 140 degree CCPM. As I mentioned
before, if your radio supports 140 then go for it, if not, don't
bother tinkering with mixes. Several pages of the manual have
steps for both documented so make sure you're following the
correct drawings for your choice of control system. By
step 1-3 you start assembling components according to your
choice so you really do need to have that worked out before
starting.
I
like to emphasize in my articles that most helicopters today can
be either built or they can be assembled. Anyone that can
manage a Star Wars Lego set can "assemble" a modern nitro
helicopter. Once you fly one that has been "built" though,
you will know that the extra time and effort required is a
minimal price to pay for a silky smooth helicopter. Radio
components and bearings will last longer because vibration is
minimized as all rotating parts are dial indicated or balanced.
Red anodized swash
New fan hub
Anodized and machined parts
Frame up
Carbon frame stiffeners
Fuel tank installed
The Vibe 50NEX parts are bagged by step and clearly labeled.
As I said earlier, the instruction manual is excellent so it
would be of little value to regurgitate it here, I will just
throw a few notes in where I feel that clarification could be in
order.
The Vibe is built by first putting together a series of sub
assemblies and then when you get to the main frames things start
coming together quickly. While you're working with thread
locker, best results will be obtained if you take a few minutes
to clean the hardware you're working on with alcohol. We will be
using Omicron thread lockers from
Lynx Heli Innovations to build
our Vibes.
The first step is to assemble the clutch bell and start shaft.
This is also the first place you can start your attention to
details. If you're planning on running a governor, go
ahead and install the magnets now and balance the clutch bell.
One of the things I really like about the Vibes is that the
governor magnets mount on the clutch bell and the sensor has
it's own little spot on the frame. This means that if you
have to pull the motor, the sensor and wiring stays in the
helicopter.
Even though the AR7100R includes a rev-limiter, I've had such
great luck with the AeroSpire Mult-Gov governors that is what I
decided to stick with one on my NEX. I've flown the
included limiter and it works just fine and saves you some
weight and wiring so if I didn't have a Multi-Gov handy I would
use the built in rev-limiter without hesitation. In the
case of governors that use two magnets, stick the magnets
together, mark the outside faces with a Sharpee, and install the
magnets so that the black marks are either both facing the
clutch bell or both facing the up.
In step 1-3 Double check that you are assembling the bell cranks for your CCPM
control system of choice.
Step 1-5 We used light machine oil to lubricate the
autorotation bearing. Don't over torque the screws or you
can distort the tail drive gear. The gear is even marked
"up" to make sure you get the orientation correct.
Step 1-6
We made sure there was no mold flash around the tank inlet and flushed the
fuel tanks with alcohol prior to assembly. I don't want to
sound gross but natures best lubricant to get the rubber stopper
in place with the least amount of fuss is a dose of spit.
Step 1-7 just saved you at least 30 minutes compared to the
radio tray on the original Vibe.
Elevator alignment pins
Vibration isolated fuel tank
High quality bearing blocks
Aluminum engine mount
Carbon frame base plate
On its feet
Step 2-1 It's time to start on the main frames. Some
important notes in this step include noting that there is a left
and a right side frame, and not all the bolts get thread locker
or tightened down at this time. Here also we observed
another difference from the original V50 and that is that JR
went back two main shaft bearing blocks with the NEX where the
V50 had 3. We used a product called Epo-Grip epoxy to
install the elevator pivot pin bearings into the main frames
after scuffing up the flange on the bearing with a jewelers file
for best adhesion.
Step 2-4 I really like the frame brace, they borrowed this from
the 90SG and it looks great and I'm sure it will really stiffen
up the frame. This may be one of the reasons they omitted
the 3rd main shaft bearing block.
Step 2-5 shows one of those details that really made us say "wow
that's cool". JR provides two alignment pins that when put
in to place hold the elevator A arm perfectly square while the
set screws are tightened. This took a little bit of guess
work out of aligning the elevator linkage that I remembered
taking a bit of trial and error in the V50 build. Nice
touch. When everything is done, remove the pins, flying
with the elevator locked won't be any fun!
Step 2-6 Don't be alarmed if you have parts left over, spacers
are used depending on the control system you have chosen.
Study the line drawings carefully, the bell cranks mount in
different holes for 120 and 140 CCPM.
Step 2-7 If you're unfamiliar with the V50 the Vibe fuel tank
mount uses a simple system to isolate the fuel tank from the
frame to prevent transmitting vibration to the fuel. The
NEX continues that tradition and accomplishes it with less
screws. On both Vibe versions fuel tank removal is a quick
and painless task.
Step 2-8 Three cheers for the injection molded radio tray!
Step 2-9 JR provides a gyro mount if you want to mount your gyro
sensor behind the main shaft, we omitted this on both of ours
and mounted the sensor under the receiver on the flat spot on
the radio tray, so far both have worked fine. This is also
the step where you install the body mount plates on the rear of
the frame. If you're unfamiliar with these, they provide a
break away point for the rear canopy mounting post that is
designed to save both your frame and canopy from damage in the
event of a crash.
Fan/clutch balancing
Fan installation
Engine installed
Run out checking the fan
Head block and spindle
Rotor head assembly
Step 3-1 This is the step where you set the gear backlash and
tighten everything down. The main gear should be rotated
until you feel the most resistance, if there is a high spot from
the molding process this is where you want to set the gear mesh.
As the instructions note, insert a piece of notebook paper
between the gears and set the mesh. When you have everything
tight run the piece through the gears, it should come out
looking like a sharply folded accordion. If it comes out
wavy its too loose, if it comes out mangled, its way too tight.
Too loose and you risk stripping gears during high power
maneuvers, too tight and you generate heat and rob power from
the drive system. Before you tighten any of the bolts
holding the main shaft, test that the main shaft drops freely
through the bearing blocks before and after tightening.
Step 3-2 Since the engine is turning in the neighborhood
of 17K rpm this is one area where balancing and checking run out
will pay dividends. High frequency vibration generated by
an out of balance clutch/fan is an electronics killer and will
also cause fuel foaming making the engine run lean. We
used a magnetic prop balancer, and a dial indicator to get the
best possible setup in this area. You can adjust the run
out by rotating the fan 90 degrees at a time until you end up
with the least amount of run out, and then the entire assembly
is placed on a magnetic prop balancer. Small divots can be
drilled in the fan on the heavy side until the fan stops at
random spots when rotated. Our fans were installed using
the OS delrin plastic crank lock tool to tighten the fan and
then the prop nut. This might sound like a lot of
tinkering but trust me, its easier than the collet design and a
whole lot simpler to remove the fan when you have to service the
engine.
Step 3-3 When you tighten down the engine mounting bolts
use a 6mm start shaft to spin the start shaft backwards and
slowly nip up the bolts one by one until everything is tight.
If you feel resistance back off the bolt you're tightening and
move to another until they are all tight and the start shaft
rotates with the least amount of drag.
Step 3-4 Talk about the small touches that add up. Each
washer/retainer for the fan shroud has a rubber o-ring on it so
it stays snug without over tightening the self tapping screws
that are going into plastic. Should you strip out the
plastic, medium CA is the ticket, don't use thread locker on
plastic.
Now that the helicopter is framed up and sitting on its skids
it's time to add the main rotor head and the tail assemblies.
Step 4-1 The swashplate is an absolute work of art.
Neither of ours needed any adjustment but should slop develop
between the swashplate rings the set screws to adjust that out
are already supplied.
Flybar cage
Setting gear mesh
Link assembly
Precision link measurement
Main head block
Main rotor head and grips
Step 4-2 Enjoy the red anodized washout arms as you complete
this assembly. Double check that everything is built
correctly, the JR logo will be on the outside.
Steps 4-4 through 4-6 Lubricate the spindle with silicon
dielectric grease where it goes through the flap dampeners, just
don't get any grease in the threads where the spindle bolt goes.
The thrust bearings consist of two bearing races and a ball
cage. The ball races have a different ID or inside
diameter and must be assembled correctly with the larger ID race
on the inside towards the head block. The easy way to tell
the difference is to slip the races over the spindle and rock
them back and forth with your finger. One will hardly move
at all, and one will rock several degrees back and forth.
The one that rocks easily is the one that goes towards the head
block.
We built both of our Vibe 50 NEX's using
Lubriplate EMB small bearing grease to pack the ball cage on
the thrust bearings. The NEX moves the thrust bearings
outside the radial bearings instead of inside the grips between
the radial bearings. The Avro Blitz, which can be built
both ways, claim the outboard thrust bearings are better for 3D
where the inboard thrust bearing is recommended for FAI style
flying. I've asked around some of the top FAI pilots and
none felt it would make any difference.
Lubricate the main shaft where the washout base and swashplate
slide with light machine oil.
Step 4-7 through 4-8 A
metric ruler will come in handy in the next several steps.
This is an area that benefits from attention to detail.
Get the distances for the flybar centered perfectly and when
you're done use a set of paddle gauges to align the paddles to
the flybar cage and each other. The V50 had removable
weights, those are gone and though my gram scale has been
borrowed and not returned I estimate these to be in the 10 to 12
gram vicinity. The NEX flybar paddles are also thinner and
with a sharp leading edge, both design departures from the V50.
Step 4-9 Calipers are
your friend! All the linkages on the Vibe are built in
pairs with the exception of the throttle and rudder so getting
everything the same length is paramount. Dial or digital
calipers can be had relatively inexpensively and have a lot of
uses but they really shine when building push/pull control
systems.
Main grip and thrust bearings
High quality bearing blocks
Torque tube and bearing
Tail hub with thrust bearings
Improved tail case
Completed tail grips
Time to build the back end.
Step 5-1 through 5-3 The
Vibe 50 NEX features a bearing supported aluminum torque tube
drive for extremely positive tail control. We affixed the
bearing to the torque tube with Permatex green thread lock.
The tail case is beefed up a bit and the tail output shaft
bearings are both recessed. The kit includes shims to set
the tail gear mesh.
Steps 5-5 and 5-6 When
installing the tail pitch change fork watch out when tightening
it down, it needs to be snug but if you over tighten it, even
once, it will tear up the bearings in the slide ring. The
tail pitch control lever features a two point connection for
positive control and
when assembled with the supplied pins is free of the drag that I
have had to work out of some other similar designs.
Step 5-7 and 5-8 The new
and improved tail rotor hub is another NEX component borrowed
from a 90 size design. The tail hub sandwiches a thrust
bearing between two radial bearings. Not many 50 designs
incorporate a thrust bearing supported tail rotor. The
thrust bearings are assembled the same way as the main rotor
spindle thrust bearings. Find the larger ID bearing race,
put it towards the center hub, and lubricate the bearing cage
with Lubriplate EMB.
After a few weeks with the V50
I had some vibration issues with the tail rotor that were
getting worse by the day and none of the traditional culprits
seemed to be the source. I finally swapped tail blades and
the problem went away. Close inspection revealed that the bolt
holes in the plastic tail blade root had elongated and were the
cause of the problem. We always build our review models
stock but I'll be keeping a close eye on the tail blades.
Oil the tail rotor output shaft where the pitch slider moves
when you're done putting everything together.
Step 5-12 The tail rotor
pushrod guides on the V50 seemed rather clever at the time I
built my kit. They could be removed or installed without
taking the boom off of the helicopter and the distance between
the rod and the boom could be adjusted. The rod was
captured by serrated jaws and you could loosen the screw and
move it in and out. After some regular flying it turned out that
the design was a little too clever. The jaws would wear
out and I had few landings where the rod was hanging out of a
guide. With the NEX they went with the less is more
concept. The guides are still removable without pulling
the tail boom and the distance is still adjustable but the whole
thing is more solid and appears more reliable. Sight down
the rear of the boom and get the pushrod run as straight as
possible. The intermediate bell crank at the rear of the
main frame allows the servo to remain up front where it's safe
and out of the exhaust. The setup has the stiff and
positive control and straight control run of a tail mounted
servo while moving the weight of the tail servo ahead of the CG.
When you have completed the
tail boom assembly and installation, give the tail gear mesh
another check as you tighten everything down.
AR7100R reciever
Servo installation
MP80 Tail servo and 8717's
Radio
Equipment Installation
While the servo
installation sequence isn't spelled out, it is implied by the
order of the pictures that you start at the top and work your
way down. Life will be much easier if you start with the
rudder servo, then do the left swashplate servo before
installing the last two swashplate servos on top. The
throttle servo is well accessible and can be installed at any
time during the sequence. Doing the rudder servo first
will save you some colorful vocabulary.
My Vibe is getting
8717 servos on the swashplate, an 8311 throttle servo, and a
JR G370 3D Gyro and
MP-80G brushless servo on the tail. The 7100R receiver
will allow me to run the gyro and tail servo at 5 volts and
supply 8V to the servos. (Note: JR makes the 8717HV and
8917HV servos that are supported to run on 8V. While I have been
successful running my standard 8717s this way it is outside of
specs and if you choose to do so you are doing it at your own
risk)
The G370 3D gyro
functions and flys much the same as the 770 does but its about
half the height and protected by a nice aluminum case.
Mated to the quick .05 brushless MP-80G servo, it made for a
very solid combination that fit well in the nose under the
receiver. This served two purposes, first it makes the
wiring job easier and neater because every thing is up front and
second, it keeps weight where the NEX needs it, up front.
We really noticed
the new links supplied with the NEX when assembling our two
kits. Like the aforementioned tail rod guides, the V50
links were nice but these are both better and simpler.
They take a good bit of force to snap in to place or remove, to
the point I thought they were going to need a reamer, but once
snapped on the linkages are smooth as butter and slop free.
Unless you have really tough fingers though, ball link pliers
are a must for getting these off.
JR even improved
the canopy. Thumb screws replace the need for an allen
wrench for easy removal of the fiberglass canopy. Also
either control system has plenty of clearance, with the V50
using 140 CCPM I had to take a Dremel and sanding disk to the
canopy so that the control rods would clear without hitting.
The decals are attractive and easy to apply if you choose to use
them. I made up an 11X logo and cut it out of vinyl for
mine.
If you wish to
apply the decals wash the canopy and your hands with dish soap
to clean up any mold release and finger print oils. Then
cut out the decal and immerse it completely in a solution of
warm water with a few drops of dish soap. Place your
finger in the water and wet the area where the decal will go and
apply the decal wet to the surface. While its wet you can
slide it around and get it perfectly positioned. When you
have it where you want, take a paper towel on your finger tip
and starting from the center of the decal squeegee all of the
water from under the decal while burnishing it down. When
you're done let the canopy sit in the sun for an hour or so.
Just like your
choice of tires affects the way your car drives, main rotor
blades can have a major effect on how your helicopter flies.
Most pilots like to tune the way their helicopter handles by
their choice of main rotor blades so JR has left this choice to
the end user. Edge, Radix, SpinBlades, Mavrikk, SAB and
others all make wonderful carbon main rotor blades. SAB's
are usually heavier and good for smooth FAI style flying and
auto rotations. Radix stick bangers are light and great
for, well, stick banging 3D but they don't auto particularly
well. With this in mind, I like a middle of the road
blade, one that is light and snappy enough for aerobatics but
will hold rpm in an auto so my personal blade choice for the NEX
is the RotorTech 610mm main blades. I also flew the Edge
603mm flybar blades and really liked them but I had to put them
back on my friends helicopter when he noticed them missing.
To get the center
of gravity correct we had to add between 1.5 and 2.5 oz of
weight to our Vibes (mine took less because of the heavier 8717
servos) for proper balance. Both weighed in right at 7lbs
12 oz though.
Lets get the radio setup!
Governor sensor
G370 gyro
Volts 2S Receiver battery
140 CCPM selected
Pitch curve to 50's for
setup
Ready for a test flight!
The JR
11X is an extremely capable radio for helicopters and probably
does more than most helicopter pilots will ever need. This
includes support for just about every swashplate you might run
into so it was an easy choice to build my Vibe with 140 degree
CCPM.
After doing the servo installation we created a new model and
powered everything up with no linkages connected. Set up a
throttle a linear throttle curve in Stunt-1 from 0 to 100 and
set the pitch points to 50-50-50. The reason for this is
when centering and squaring your linkages you don't have to
worry about the stick getting bumped, no matter where the
throttle stick is the swashplate servos will be centered.
Now is also the time to enable EXP in the swashplate menu
or an electronic swashplate ring if you plan on using them (I
use both).
Using round servo wheels and a ruler against the main frame,
find the holes that give closest to perfect alignment. If
you do this step right you will find that you need from 0 to
just a few points of sub-trim to get the linkages perfectly
level. Removing the main rotor head for now and using a
swashplate leveling tool that slides over the main shaft will
really let you get things perfect.
Once you get all the servos moving in the same direction when
moving the collective stick by using servo reversing use the
swash mix to get everything moving in the correct direction.
Even though the NEX uses leading edge control on the main grips,
the swashplate moves up for positive pitch. Now you can
use the swashplate leveling tool and use the end points of the
individual servos to get everything perfectly level at the top
and bottom of the throw.
When you're done install the rotor head and use a pitch gauge to
set your final swash mixes for total throw. My NEX is set
up with 11 degrees positive and negative collective throw and 8
degrees of cyclic throw. I upped the collective to 12
degrees for the video flight because my test pilot likes a
little more pop than I do.
The JR 3703D gyro is a lot of gyro in a little bitty package.
The instructions include a setup for the Vibe 50 and when paired
with the new brushless tail rotor servo the combination worked
very well with their suggested settings. Pay attention to
the instruction sheet if you use this gyro, unlike other gyros
that have expo built it, the starting point for the 370 and 770
gyros is around 40 to 45 percent. Mine ended up at 50
percent to have a nice smooth feel around center stick as well
as preventing me from disturbing the tail during tic-tocs.
Unlike some of the JR and Spektrum radios, the 11X (and the
93/9503 series) support a tail lock mode that displays the
actual gain in use. The gyro was set to N or normal mode,
the limits set. Then I dialed up Tail Lock mode and set 70
percent gain as recommended in the 3703D manual. I knew
from experience that running a high dual rate on the rudder
channel would likely result in an alarming piro rate so I
started at 80 percent on the rudder channel (final adjustment
was 85 for a spirited but controllable piro rate).
Setting up the tail servo throw and the throttle servo stroke
are a perfect application for the Hangar 9 Inline Amp Meter.
When you plug the meter between the receiver and the servo you
can verify the loaded voltage the servo is seeing, and observe
how many amps that it's drawing. Run the end points up
until you see the current start to rise and you will be able to
set your servo limits exactly for full throw with no binding.
I
gave some thought to the cyclic expo, I usually run about 20 to
25 percent on the elevator and aileron. I decided to up
that to a starting point of 30 because I thought the paddles might be a bit more
spirited than the V50 and better safe than sorry.
MAIDEN TIME
At the field we did a final inspection,
fueled her up, had a little Red Bull to calm the nerves, and
fired up the engine for the maiden voyage. Since the
engine and pipe combination came out of my V50 I didn't have to
mess with breaking in a new engine so it was time to get to work
on the test flying.
Even without breaking in an
engine, I always take it easy for the first flight on a new
helicopter. I fueled the NEX up with Rotor Rage 30 percent
premium helicopter blend from Byrons fuels and fired up the
engine.
This is the time to make sure the
CG is ok, get a feel for the gyro and the cyclic response and
make any tuning adjustments. Everything went ok and
the only adjustments I made were to up the gyro gain little and
decrease the expo on the cyclics a bit. After the flight I
checked over the whole helicopter for any loose screws and the only ones
I could find were on the pilot so I fueled her back up and
turned it over to Jeremy Strickland to get the flight shots.
Aside from adding a bit of throw
to the collective (12 degrees total each way) and a bit more rudder travel
to get a faster piro rate,
he pronounced it ready to shoot some video. Watching
Jeremy fly any helicopter at our field and it becomes immediately obvious
that it's not what helicopter you fly or how many upgrades it
has, but how much you practice that determines how well you fly.
MILD
Flying the Vibe 50 NEX is a pleasure, if
it were a car it would be a Lexus or BMW. Smooth and solid
are the first key words that come to mind when trying to
describe flying the NEX. Everything feels locked in and
maneuvers like funnels and hurricanes that with other
helicopters I find myself correcting all the time, the NEX finds
its happy spot and just keeps going around and around.
I thought that the paddles might
be a bit snappy for my style or even take away some of the
stability the Vibe head is known for but during fast forward
flight they exhibited no pitchyness.
Big loops in both directions
were large and stately. Frank looks like he's back in his
trophy winning pattern days when flying his. This may be a
somewhat over used description but the NEX really does roll like
its on a string.
To test a gyro/servo combo I usually go
way up high, point the tail straight down and let her rip
towards the ground, if it stays put I do it again with the tail
out 90 degrees to the fall. Though it's size makes it look
more at home on a 450 the 3703D gyro held up without blowing
out. Hurricanes and rolling tail slides? No problem.
It also held a nice consistent piro rate during piro flips and
pirouetting funnels.
WILD
If you watch the video I probably could
save myself some typing here. Piro flips, piro funnels,
snakes, tic-tocs, the NEX does it all. The RotorTech
blades and the stock paddles make a great combination if you've
had a bad day at work and want to head to the field and beat up
your helicopter.
The Voltz 2S Lipo feeding the
AR7100R driving the 8717 servos gives the NEX more than
enough control authority. One thing that would really have
me licking
my lips to try is this helicopter with one of the 55 or 56
engines and a good pipe. Don't get me wrong, it does very
well with a 50 but when combined with the airframe design refinements I
think one of the bigger engines would make the thing fly even
more like a small 90.
Flight Shots
There's a lot of choices in the 50
size helicopter market so what makes the Vibe 50 NEX stand out?
A mature and refined design
with great pedigree for one.
High quality parts that won't
be failing and wearing out all the time for another.
Flexibility in choosing the
control system that best fits your existing radio equipment.
When you add the three together
you get a great flying and reliable helicopter that's worth its
somewhat higher price tag.
The locked in feel gives
intermediate pilots confidence to progress to backwards and
backwards inverted flight knowing the NEX will go where you
point it and stay there.
Would I buy another NEX if
something happened to this one? Yes, absolutely!
Distributed by: Ready Heli
1700 Park Lane S. Suite #8
Jupiter, FL 33458
Phone: (888)RDY-HELI (888-739-4354)
Website: http://www.readyheli.com/
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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.