Features
The Century 50NX features a new composite G10 frame that offers a more rigid platform for extreme 3D flight. This design also incorporates new breakaway tabs that prevent frame damage. The 50NX also features a programmable head that can be set for any skilled pilot from beginner to advanced 3D. The reviewed kit includes a powerful exhaust system and the popular Rotortech 610 mm carbon fiber blades. Century has also included a new 3D main gear and pinion with the kit to make the 50NX a true powerhouse 3D helicopter. Let's take a closer look at the Century 50NX.

Main frame
Component layout: The cyclic servos are conveniently located on a separate servo tray that is protected by the canopy. The throttle servo is located below the cyclic servos mounted to the side of the radio tray. The tail servo is mounted to the tail boom clamp using a G10 bracket. The fuel tank rests between two G10 lower frame pieces behind the main shaft.

Design: Century decided to beef up the original frames using a combination of the standard plastic top half and a new stronger G10 fiberglass bottom half and radio tray. Century has also beefed up the plastic main shaft bearing blocks by adding two G10 plates that keep everything aligned even under the most stressful maneuvers. These supports also offer new mounting points for the control system and the antirotation bracket.

Swash control: Century decided to take its 120-defree CCPM system and improve it by adding new bellcranks that line up to the swashplate equally on each axis. As mentioned above, the cyclic servos sit side-by-side in a plastic servo tray up front, and single pushrods connect to plastic bellcranks.

Canopy: The canopy for the 50NX is made from plastic bleach-bottle material and is precut and ready for the windscreen and decals. The windscreen needs to be cut out, but the decals are all laser-cut and ready for install. The canopy mounts to the mechanics using a slide-on clip on the bottom of the canopy, and two rubber grommets snap into two aluminum standoffs on the top.

Landing gear: The landing gear is made from a black durable nylon plastic. The four-piece gear mounts to the helicopter using four new aluminum feet that really create a solid connection from the landing gear to the frames. The skid pipes are held in place using four setscrews.

Drive train
Engine mount: The engine mounts to an aluminum engine mount that is machine-lightened and universal (can mount to any 50-sized nitro motor). The mount attaches to the new G10 frames using four screws.

Clutch: The clutch is much like the other Century models as it is located before the cooling fan. The clutch is housed in a CNC aluminum clutch bell. The clutch liner was already preinstalled and ready to go. No sticking or excessive clearance was noticed.

Cooling fan and shroud: The cooling fan is made from plastic and does not have any predrilled holes for a governor magnet. A metal hub is installed on the fan hub using two machined screws. The hub has a press fit steel hex socket for starting the helicopter.

Main gear: The Century 50NX comes with both the standard main gear and an additional 3D main gear and pinion. Both gears are made from a composite plastic and are seen in many other Century models. A secondary gear that is driven by the engine rotates a secondary shaft and pinion that meshes with the inside of the main gear.

Autorotation drive: A one-way bearing is located in the secondary gear and is press-fit into an aluminum hub. The tail is driven during an auto as the tail bevel gear directly meshes with the main gear's crown teeth.

Tail drive: As mentioned above, the tail is driven by the crown gear that is molded into the main gear. A bevel gear meshes with the crown and drives the torque-tube coupling. The alignment is straight, so there is no need for a secondary drive.

Rotor head
Washout arms: The washout arms are made from the same composite plastic as the frames and are dual-ball bearing-supported with a brass spacer inside. The arms do not have any output options. The swash links are pinned to the washout arms and are made from the same durable plastic composite. The washout base is made from plastic and has a brass sleeve that is pressed in.
Bell/Hiller arms: The Bell/Hiller arms are directly mounted to the main-blade grips. They are made from plastic and are dual-ball-bearing supported. The arm can be flipped giving you an additional output option.

Main-blade grips: The plastic blade grips are dual-ball-bearing supported along with a thrust bearing. The grips attach to the spindle using a lock nut on each side. No input options are available. The blade grips are molded with the pitch arms and extrusions for added strength and rigidity.

Headblock: The headblock is constructed using two different materials. The main hub is a solid piece of aluminum with screw taps to mount the seesaw. The hub attaches to the main shaft using a single jesus bolt and a clamp on each side. A molded plastic T is press-fit to the aluminum hub. The fit is very tight; no slop is seen. The dampers press into the end of the plastic T and seem to be a little mushy for 3D.

Phasing: The phasing is accomplished with a separate aluminum-phasing ring. The ring is secured to the main shaft using two setscrews. The pins on the test model were a little bent, causing some binding issues with the washout base, but with a little tweak it was working smoothly.

Swashplate: The swashplate is made from CNC machined aluminum. The swash does not have any slop and slides freely up and down the main shaft. A fourth arm is also machined, and a steel antirotation pin is screwed down to this arm. The antirotation bracket is made from aluminum, as well, and attaches to the new G10 frame stiffeners using the two screws that attach the left and right bellcranks along with an additional two screws.

Tail
Boom: The boom is anodized black and is 20 mm in diameter and 710 mm in length. The boom has a slot cut out in the front to align the boom with the frame. A hole is also drilled out in the back with which a pin from the tail case aligns. This setup keeps the boom from rotating unintentionally. The torque tube has a single support with two O-rings in the middle that are bearing-supported.

Tail case: The composite-plastic tail case is molded with an extended bracket to mount the pitch-actuator arm. A pin is located on one side to prevent the tail case from rotating, and a hole is drilled out on the other to inspect the setscrew tightness on the reardrive gear.

Tail blade grips: The tail blade grips are made from the same plastic as elsewhere. They are bearing support, and they include a thrust bearing in each grip. The grips have three input options and are held onto the hub using nylon locknuts. The blades are held in using an Allen screw and a nylon locknut that is recess-molded into the grips.

Pitch actuator system: The pitch actuator system is made entirely from plastic and has a single point attachment to the pitch slider. The pitch slider is dual-ball-bearing supported and has a brass sleeve that screws down. The two pitch links are pinned to the fork and attach to the grips using a ball link.

Testing
We opted to use some of the best radio gear we could find so we could give the 50NX a true test of its 3D performance. Since this helicopter did not have a governor mount or any holes predrilled into the fan, we decided to use Spektrum's AR7100R with built-in rev limiter and a crank pin sensor to regulate the head speed. Let's see how this new Century helicopter performed! Ratings are based on a five-point scale.

Hovering: Hovering the 50NX is straight-forward - it seems to hover with the best of them. The response is a bit slow but nothing out of the ordinary. Once locked into a hover, the 50NX does not require much input to keep it stationary. This includes the collective as well.
Rating: 4

Forward flight: Pushing the nose forward and moving into forward flight, the 50NX tracks very well. It isn't a fast helicopter but feels very stable in forward flight. I noticed the phasing was off a bit during figure-eight circuits, so I landed and, with a couple twists to loosen the phasing ring and a slight adjustment, I had the 50NX flying perfectly with my inputs.
Rating: 4

Cyclic pitch response: I started with about 70 percent on the cyclic and felt that the 50NX was not fast enough even with the aggressive settings and lightweight paddles that were included with the kit. I bumped the value up to about 80 percent, which was about the max I could get out of the swashplate without it binding against the main shaft. This sped up the cyclic a bit, but I still felt as if it could use more. The response also felt a bit slow - it did not react as fast as I would have liked. Overall, if you like a locked-in feel and enjoy smooth flying performance, then these features would accent your flying style. With the addition of some aftermarket paddles and dampers, this helicopter would be much more aggressive for the 3D enthusiast.
Rating: 3

Collective pitch response: The collective on the Century 50NX feels locked-in during all flight modes. The response is crisp yet very manageable when you want to lock your helicopter in a hover. The pitch range is more than adequate to pull the helicopter around and across the sky. The included 610 mm carbon-fiber blades and the optional included 3D main gear really make the collective shine.
Rating: 4

Tail rotor response: The tail rotor response feels very crisp and offers plenty of pitch to correct for the hardest 3D maneuvers. The tail accelerates and stops very smoothly while offering plenty of piro speed for even the most aggressive pilots. In some fast backwards flight the tail wanted to blow out - this could be caused by the stock plastic blades, which seem to be a bit on the flexible side. A quick change of these blades made the tail hold rock-solid during any maneuver.
Rating: 4.5

Autorotation capabilities: Even though the gearing is a bit different on the Century 50NX than the standard design, it offered smooth, drag-free meshing. The main blades retained plenty of energy at the bottom of the autorotations. The tail is driven during an auto, which gives you the option to perform some aerobatic autos.
Rating: 4

Post-flight inspection: Looking over the helicopter and inspecting the main gear, I found that the gear that drives the torque tube was looking a little worn. Looking inside the canopy confirmed that the gear was losing some plastic. When building this helicopter, you will want to pay close attention to the gear mesh to make sure you have everything perfect. I replaced the gear and adjusted the mesh and have not had a problem since. Every other part on the helicopter has held up and has no signs of premature wear.
Rating: 4

Conclusion
Overall, the Century 50NX is not the fastest helicopter you can get out of the box, but it is a very solid performer. If you like a machine that is smooth and responds with style and grace, then this 50-sized helicopter is a perfect choice. The addition of G10 frames makes this a reliable and ridged helicopter that will last you for years to come.

When you open the box
When opening the box, you will find the helicopter in parts that are individually separated in bags that are labeled and ready. The white plastic canopy is precut and requires the windscreen to be cut out and attached. The manual is packaged with nice-looking decals. The included muffler and blades are packaged in their separate boxes and located in their own section of the box.

Manual and build
The manual that is included with the kit is printed on big paper (11 inches by 17 inches). The manual does a great job showing you where every screw and part is located. I found that some of the build is actually a bit difficult due to looking for the parts. Some sections have parts in differently numbered bags, which creates a bit of confusion when assembling that section. Another difficultly in building is joining the frame top to the bottom. This requires that you work the gear train around the fan - and that can be somewhat difficult if you have never built a Century helicopter before.