A full, detailed review with over 100 photos including the illustrated manual of this new nitro 50 from China!
Over the last decade, the manufacturing might of China has significantly influenced the Western hobby industry. For the R/C helicopter enthusiast this has meant a boon of affordable models, equipment and parts readily available whenever the want arises. While many of the pioneering R/C model helicopter companies have disappeared, new companies have been popping up and offering a myriad of exciting products.
Hiflier-Tech Company, LTD of the Chengdu economic and technology district in China is new to the R/C helicopter scene, but have developed a new 50-size nitro model that offers unique features with a high performance flight envelope. The model flies under the name of Aeolus 50 3D. Aeolus is the Latin spelling for Aiolos who was the god of the winds in ancient Greek mythology. Aiolos translates to fast shifting and sparkling. We’ll see how this model holds up to its namesake!
At the onset, this model shares many component similarities with that of the Align Corporation’s Trex 600 Nitro model. Despite the similarities, there are significant positive differences. The single-axle CCPM input control system is one of the most effective designs at minimizing control interaction and reducing wear and tear on the servos. Many high-end models like the Hirobo Eagle3 series and Kyosho Caliber 90 implement this proven control system.
The engine mount is a practical, modular design and makes for speedy installation and service. With a pop of the throttle linkage, fuel feed line and fourteen screws the engine and clutch assembly separate from the airframe. There is no need to remove any base plate (it doesn’t exist on this model) or the landing gear. I’m of the opinion that anything designed to make working on a model easier and less time consuming without compromising performance or strength is of high value.
The first thing I do when I receive a new model is to open the box and inspect how the contents are packed. The model packaging is quite compact. However, I was a bit dismayed to find that the edges of the fiberglass canopy had cracked in two spots. This was likely a result of the mass of parts nestled inside the cabin shifting in transit. The fiberglass canopy is the most delicate part of the model and needs better insulation from potential damage. To prevent further cracking and lifting of the paint I wicked in some thin CA glue.
I found each parts bag labeled with corresponding letters and numbers for each step in the manual. You will have to provide your own 600mm main rotor blades; however, AHF does include one set of stiff plastic 92mm tail blades. Several parts come pre-assembled from the factory, but I will be checking them for properly assembly and the inclusion of thread lock and glue where applicable. Aside from the canopy, the remainder of the model’s parts showed no other signs of damage.
Aeolus 50 3D GF Specs & Features
MAIN ROTOR DIAMETER:1348mm
TAIL ROTOR DIAMETER:263mm
DRIVE GEAR RATIO:8.5:1:4.5
Graphite fiber frames & tail fins
Plastic rotor head, metal yoke
Belt driven tail
The Build and Tips
For Step A-1 I disassembled the clutch assembly and found no thread lock had been used on any of the metal threaded components. I confirmed that the factory greased the bearings. I cleaned all of the metal with Simple Green, applied medium strength thread lock and reassembled the components. I decided to install the included governor magnet in the clutch bell. I thought I would drill a small hole into the magnet recess in the clutch bell to relieve any air bubbles that might occur after gluing the magnet in place. During the process, I discovered that the material was paper-thin and it easily tore open. To remedy this I flattened the torn aluminum back into place. Then I removed the M2 button head screws from the clutch bearing block (this keeps the magnet from attracting itself out of the clutch bell recess while you’re waiting for the epoxy to dry), smeared in some 24-hour JB Weld epoxy and then carefully pressed in the clean magnet. I let this set overnight to cure.
For Step A-2 I found no thread lock on the M3x11.6mm x 2 specialty screws. There was some excess plastic flashing on the inside hole of the elevator control arm recess. This wasn’t anything crucial, but just indication of the lower quality plastic molding process.
In Step A-3 I verified the main shaft bearings were greased and cleaned residual oil from the inside of the plastic bearing blocks.
For Step A-4 I made sure to clean all of the machining oil off the hardware with Simple Green. I installed the four fan screws dry and checked the balance. The fan required several ¼” divots to bring it into balance. I made sure to apply some medium strength thread lock to the four fan screws and a light coat of tri-flow oil to the brass collet before installing the assembly on the crank. I used the engine’s prop nut and applied medium strength thread lock to the crank threads to ensure it stays tight.
I verified that the link balls had been glued in by the factory for the assemblies in Steps A-5 and A-6. I did have to clean the button screws and apply thread lock.
In Step B, I found the supplied clunk tubing to be very thin. This thin tubing is prone to folding over on itself creating a kink. This could lead to engine leaning or cut out in flight. I always replace this line with thicker fuel tubing. I obtained a suitable length of tubing for the clunk from the other fuel line supplied in the kit. While the stock brass clunk will work fine, I installed an OMI fuel magnet for peace of mind. Make sure to lube the tank grommet with after run oil or something similar and carefully install it with the fuel nipple into the tank. I worked the inside lip of the grommet into the tank with a wide screwdriver blade being careful not to cut the rubber.
After completing the fuel tank assembly I pressure tested it in a bowl of water. It tested out good with no visible air leaks.
For Step C-7 carefully tighten the M3 button screws for the metal clutch-bearing block so as not to crack the frame nearest to the main gear opening. This was the first screw that I tightened in the frame and just my luck, I went just a smidge too far and the frame cracked. I quickly wicked in some thin CA to the crack and shored up the screw.
In Step D-8, I used thick CA to secure the plastic caps to the skid pipes. I ran the M3 set screws into the landing skids before installing the skid pipes, then backed them out and cleaned out the plastic flash protruding into the hole. This allows the skid pipes to easily slide into the skid struts. I set the pipes into the struts leaving 24mm of pipe sticking out from the rear edge of the rear strut. I then tightened the setscrews slowly until I felt and could hear them touch the pipe, and then just lightly snugged them down.
In Step E, I discovered that the outer race for all of the thrust bearings had been etched with the word “OUT”. This insures that you install them properly. I verified the inside diameter of the races and the “OUT’ was marked on the appropriately sized races.
For Step E-2 I made sure to tighten the M2 socket screw into the t-type arm.
I noticed Bando of Japan makes the belt. These belts have a very high power transmission efficiency and have a long service lift when properly cared for. The belt is a 592XL and is the same belt used by several other model helicopters.
In Step E-12, I took my time carefully tightening the frame screws. All of the frame screws with the exception of the clutch bearing block screw into plastic hex nuts. If you screw these down too tightly they can strip. I used a Metabo PowerMaxx hand drill with MIP Thorpe hex bits with the clutch set on 1.5 to install all the screws.
In Step F, The flybar measures 440mm long x 3mm diameter. When I assembled the flybar cage I found one of the flybar control rods was slightly longer than the other. While this didn’t cause any binding, it did slightly warp the control arms when fully tightened down. One rod was 74mm and the other was 74.33mm.
For Step 14 make sure to remove and clean all of the M3 button screws. I also had to tighten down the M3x12 cap head screws. In Step F-4 I noted that the swash balls had thread lock applied by the factory. The swash weighed in at 66.6 grams.
In Step 15, I found that the radius arm ball socket a little tight requiring some slight reaming to get a smooth, bind-free fit.
In Step 16, I noted that the feathering shaft has an outside diameter of 8mm, then it drops down to 5mm with an overall length of 93.18mm. I also checked the stock paddle weights with the 1.5mm setscrew installed and clear acetate stickers applied, 21.4 grams and 21.6 grams.
For Step G I notched the webbing between the servo screw bosses to allow clearance for the servo wires’ strain relief. I also found no information for the spacing of the servo link balls on the servo arms. I determined that the swash servos should have each ball set out 15mm from center.
After I installed a Curtis Youngblood MP5 muffler onto the OS 50-Hyper engine I noticed that the fuel tank had enough movement in the frames to allow regular contact with the expanded portion of the muffler. Obviously, this would be a major issue in flight, so the only option is to use a slimmer pipe. I selected a Hatori Bobby Watts fixed header pipe to clear the tank and provide excellent performance.
To mount a governor sensor in the suggested location you’ll need to use a Futaba GV-1 sensor or purchase the GV-1 sensor case and mount your own sensor inside (HSP51245 1M2J02601 Upper Case GV-1 sen, HSP51250 1m12502701 Bottom Case GV-1 se).
Upon installing the canopy to the frame, I noticed the forward mounted cyclic servo wheel on the muffler side of the frames interfered with the inside of the canopy. This servo wheel is a stock Hitec item, but I ground down the outside circumference too properly clear the canopy. However, despite doing this the canopy still exhibits a fitment problem on the right rear side. The fiberglass bows inward towards the grommet. It appears that the canopy is malformed since, aside from the front rubber supports, there are no other obstructions protruding from the airframe. I tried removing the rubber supports, but didn’t notice any improvement.
Through the process of checking the balance of the tail rotor assembly, I found that the stock plastic tail blades have a slight spanwise imbalance. I corrected this by adding a small piece of 3M Super 88 electrical tape to the leading edge of the lighter blade.
The main rotor head balanced perfectly on my Du-Bro Tru-Spin balancer without having to add any weight.
The manual isn’t very clear about the tail setup. Most other manuals detail the direction the tail pitch slider will move if you give a specific tail input. This helps you get the tail servo operating in the correct direction. The manual does indicate that you should set the tail pitch slider in the center of its travel. There was no indication of a suggested length for how far out on the tail servo arm you should place the ball. I found that the ball placed out 15mm provides a 90° angle between the pushrod and the servo arm with the rudder stick centered. I also found that the link ball on the tail pitch arm is not located on the boom centerline. Despite fiddling with the boom’s pushrod guides’ alignment, there is still a bit of binding when the tail pushrod moves to its limits.
The manual doesn’t provide any baseline radio settings. Unless you have experience setting up a model from scratch, you’ll need some assistance in doing so.
Current dry weight of the model is 3414g / 7.526 lbs. Loaded with a full tank of fuel the weight is 3750g / 8.268 lbs.
I’m using the following components:
• Futaba FASST R608FS receiver
• Emoctec DPSI Micro MPS RV regulator/switch set to 5.9vdc (Desert Aircraft)
• Fromeco Relion 2s2600 Li-Ion RX pack
• (3) Hitec HS-7975HB servos on cyclic
• Hitec HS-81 on throttle with a Custom Heli Products adapter plate
• Futaba BLS-251 tail servo
• Curtis Youngblood Mini-G gyro (ronlund.com)
• OS 50SX-Hyper
• Hatori Bobby Watts fixed header 50 muffler
• Mavrikk G5 Pro Wide Cord 600mm carbon fiber main rotor blades (heliproz.com)
I’ve managed to get +/- 12° collective pitch with a Swash Pitch AFR of +40%. My Aileron/Elevator AFRs are at -50% that yields about 6.5° of cyclic throw. Unfortunately, the bottom ring of the swash plate touches the top of the frame at low stick and full back elevator/aileron. This prevents increasing the amount of cyclic throw. A trimmer swash plate, similar to the QuickUK version for the Align Trex 600 may allow for an additional 1°-3° of cyclic throw. I also noticed that the swash plate’s inner and outer link balls are not on the same vertical plane. It appears identical to the Align Trex 600 stock swashplate’s geometry problem. This is known to cause unwanted interactions in the head.
Current Radio Settings (Futaba T10CHP):
Swash AFR: Aileron & Elevator: -50%, Pitch: +40%
Sub-trim: all channels: 0
Endpoints/ATV: Rudder & Gyro: 140/140 (will vary depending on gyro used), all other channels: 100/100
Reverse: Elevator, Rudder, Pitch, all other channels Normal
On the first test flight the tracking was spot on and the model showed no major vibrations. I was only able to get one tank through before running out of time. I checked over the machine and everything was still in good shape.
I’ll be reporting on how this model performs in a future article. However, local young phenom pilot Justin Chi has reported that this model has a bit more pop and roll rate then the Align Trex 600. See him put it through its paces in the video below!
Aeolus 50 3D GF (graphite frame/belt driven tail) USD $299.00 MSRP
Aeolus 50 3D CF (carbon fiber frame/torque tube drive tail) USD $399.00 MSRP
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