Having waited nearly two years since its conception the Synergy N9 Helicopter developed by 3D Masters Champion Jason Krause and Todd Bennett has finally become available to us mere mortals of the model helicopter world. The customers release date was set for 28th July 2006, the first competition day of the 3D Masters event. Its main distributor would be Skyline Models with Bob Johnson being one of the pre-production test pilots.
 

The parts all come very well packaged in a rather plain but smart and modern looking box with Synergy Model Helicopters N9 across the front artwork. There is no picture of the finished model at all on the box artwork which is unusual. Opening the box revealed the Build Manual CD taped to the top - good job I've got a computer then! Below this were two boxes. Opening the first you are faces with the two G10 side frames, the large white gel coated canopy, U/C legs, radio tray and fuel tank. The second, slightly smaller, contained all the remaining components individually bagged for each stage of the build. Strapped to a piece of card at the side of the two boxes were the long items such as the boom, tube drive, flybar, U/C tubes. It was immediately apparent that there were no decals in the kit. Something which should be made available in the future for those not wishing to paint the canopy. Another thing worth noting was that in amongst all the bags of parts was a small spare parts bag containing all the extra shims and some spare small parts, ball links etc. A very useful thing to have as no doubt I would loose a small e-clip.
 

The build manual consists of nothing more than a series of detailed exploded diagrams with very little in the way of instructional information. Not something a relative newcomer to RC helicopters would find particularly easy to follow, but this helicopter is designed for the experienced modeller in mind. You can download an Adobe pdf copy of the Synergy Build Manual by clicking here.

Each page of the manual relates to a numbered bag in the box containing all the small components for that stage of the build.
 

The first parts to assemble are the fuel tank and landing gear struts. The tank uses a similar system to the X-Cell Fury/Stratus rather than a Raptor in that an aluminium vent fitting must be fitted from the inside of the tank and held in place by a nut. A rather fiddly job to say the least but with patience it can be achieved! My first problem was encountered here. The nut that hold the vent fitting in place was not threaded, so it's out to the garage to hunt for a suitable replacement. A suitable replacement nut proved very elusive and in the end I managed to tap a piece of nylon or suitable size to attach to the vent. The clunk line needs to be cut to length here and I also opted for replacing the standard clunk with a 'Fuel Magnet'. A very large rubber grommet finally seals the tank.

Other than the unusual shape of the landing gear it is similar to most other helicopter in that is consists of two aluminium tubes fed through the two plastic struts. An ingenious system locks the tubes to the struts rather than just a grub screw. These skid locks are basically round pieces of aluminium bar that are cross threaded. They slide inside the aluminium tubes and act as a captive nut for the skid bolts to locate onto. Not the easiest of things to get in the correct position but by attaching them with CA to some thin doweling they can be held in place inside the tubes until bolted and then the dowel can be broken free.
 

I was fitting an OS91SZ (non-pumped) engine to my Synergy and the next item to assemble was the cooling fan, clutch assembly and pinion. The large cooling fan is similar in size to the one found on a JR Vigor and should provide adequate cooling for the large 90 size motors. Unlike most other models that I know the fan is mounted inverted which means that air is sucked upwards over the engine before being blown down through the shroud over the cylinder head. The fan was mounted to the hub and then checked for balance. The fan assembly is attached to the engine and automatically centred with the brass collet. The clutch is then bolted onto the fan in a similar way to a Raptor. The large 15 tooth pinion attaches to the clutch bell which also has recesses for governor magnets and the pinion is supported by two 10x19x5 bearings in a nylon block. Finally a hex start adapter is fitted to the top and held in place with an allen screw. The fan shroud then fits over the entire assembly. I needed to cut the shroud around the Hatori 938 manifold I was using and no doubt with other engine/pipe combos some minor cutting may be required.
 

The main gear and bevel gear assembly is the next job. The large black CNC machined plastic main gear holds the one way sprag bearing assembly all of which you have to assemble yourself. The sprag bearing comes in the kit with a rubber band holding it together. This is then inserted into the hub the correct way round and coated in light oil. A sleeve is then inserted through this to complete the heavy duty assembly. It will certainly be interesting to see if it locks up at all in flight but it does seem to run incredibly free and smooth so far. Like the Raptor 90 the Synergy uses a 12mm main shaft which is held by two plastic bearing mounts with 5mm bearings. Shims are provided should adjustment be needed to the bevel gear for the tail drive. Each of the plastic bearing mounts comes in two halves and are held together by threaded hexagonal aluminium inserts in the same style as the Thunder Tiger Raptor series of helicopters.
 

I was disappointed to see that the production model came with G10 side frames rather than carbon fibre as seen on the original pre-production prototype models but I guess this leaves the possibility of upgrades on the horizon and I'm sure that G10 is sufficient for this machine - It seems to be fine on my X-cell Fury after all!! The frames are built one side at a time with three metal cross braces and a 3mm front frame which the plastic servo tray mounts to. One half of the nylon engine mount is attached through the slotted holes to the large aluminium centre block. The main gear assembly and bearing blocks are then fitted in place and adjusted. The engine assembly is dropped into place and bolted to the engine mount using 40mm bolts and nylocs with shims for adjusting the horizontal alignment. Once this is all in place the cooling shroud is adjusted making sure there is adequate clearance around the fan and engine. This took a little while to achieve as there is a fairly tight tolerance between the fan and the shroud. Finally the second side frame is added sandwiching it all together.

The fuel tank is then squeezed in between the side frames and held in place with rubber U channel in a similar way to the JR Vigor. The previously assembled undercarriage is then bolted in place to the bottom of the frames. I added a couple of ball links to the underside of the U/C legs to hold an aerial tube as there is no provision on the legs for mounting an aerial. A couple of simple hoops moulded into the legs would be very useful for this like most other kits seem to have these days!
 

A block of six plastic frames holds the three cyclic servos and this is fitted to the top of the main frames next. Each of the servos has a support and bearing which is based on the X-Cell style fitting over the top of the servo after the servo horn is in place. The control system is easy and straight forward with each of the servos connecting to the heavy duty metal swash plate via pushrods and plastic bell cranks with twin bearings that are bolted to the spacers between the frames. I used the standard Futaba 6 arm servo horns although the kit recommends the heavy duty type.
 

Moving upwards to the rotor head and the metal head block comes ready assembled with the flybar see-saw attached. A first for an RC helicopter is the 5mm flybar which certainly looks chunky. How this added rotational weight to the head will affect the flying characteristics will be interesting. The flybar has location flats for the grub screws that are used to fit the wrap around flybar carrier. The kit comes with SAB 25 gram carbon paddles too which is nice to see instead of plastic items although they are no doubt expensive to replace in a crash. Plastic blade grips are attached using a teetering feathering spindle and the teetering point being a plastic sleeve with central ridge. The sleeve needed to be warmed up in hot water to allow it to slide into position. The head damping consists of four neoprene o-rings of H/R 70~80 and can be stiffened by adding a mixture of thin/medium/thick shims that are provided. My next problem with the kit was that the bag of parts only contained three main blade grip bearings instead of four. Luckily they are the same size bearings as my Raptor 90 (8x16x5) so I could 'borrow' one for the time being. There are three flybar ratios that can be used on the synergy for a beginner to full 3D flying. Having chatted to Jason Krause and a few others at the 3D Masters I opted for the mid-point set-up. Finally the head is attached to the main shaft using a Jesus Pin with grub screw lock and two clamping bolts. This all holds the head extremely well to the main shaft! The only other problem I had was shearing one of the ball links whilst tightening it to one of the arms. This took quite a bit of work to remove before replacing it. Try not to be too heavy handed when tightening the ball links!
 

The next step is to build up the tail assembly and boom. The tail gearbox comes complete and pre-assembled with a large output shaft and and opening so that you can check the gears for wear and damage. The tail blade grips use thrust and radial bearings for support and are mounted onto the metal hub using 3mm bolts. The tail pitch slider finishes off the assembly before it is all attached to the output shaft with a grub screw. The only thing I didn't like here was the spring clip used to hold it all together. It dropped off after my first attempt at assembling it. After the second attempt I added some epoxy to make sure it held! The tube drive is a large 10mm in diameter and comes with two bearing supports already in place. Each end of the tube has an aluminium coupler and collar that grips to the tube with grub screws. The front coupler has a hex adaptor to connect to the bevel gear assembly and the rear of the tube drive connects to the gearbox with four grub screws. The tube drive is slid into the boom using a touch of grease on the o-rings as with most shaft drive tail assemblies. The gearbox attaches to the boom using two 3mm bolts. The front of the boom slides into the frames between the boom clamps and is tightened into place. The 3mm thick G10 vertical 3D tail fin should withstand more punishment than a 2mm fin found on every other model on the marked today but is slightly heavier. Staying with the SAB theme a set of SAB 105mm carbon tail blades are included in the kit which should give the model awesome tail control.
 

The front of the mechanics is finished with a large plastic radio tray which has ample room for today's modern radio equipment including receiver, gyro amplifiers, governors, Li-Po's and regulators. A small mount is provided as a platform for the gyro at the rear of the side frames and a large mounting point for a heavy duty switch is suitably located below the cyclic servos. At this stage it would have been nice if they had provided some double sided adhesive sponge to mount the radio gear and perhaps some rubber bands or Velcro straps like other manufacturers do.
 

The white gel coat fibreglass canopy needed very little finishing, a screen line was recessed into the mould to allow for painting. The only thing I notice about the canopy was a fine hair line crack on the underside where the two halves of the mould had been joined together. I opted to paint the canopy with my own design which is what I would imagine the majority of builders will do even with the addition of decals in the future. Despite being a very sleek and streamlined canopy it fitted flawlessly around the mechanics and radio gear and is held in place using four large knurled thumb screws and large grommets.
 

Setting up:

I used a Futaba R1054DPS receiver with three Futaba digital 9255 servos for cyclic/collective. The Futaba digital 3152 throttle servo was controlled using a Throttle Jockey Rev Max. For tail control I used a Futaba GY601 gyro with its dedicated 9251 servo. All of this was powered by a Duralite 4000mAH Li-Ion 2S2P 7.4V battery pack and heavy duty 6V regulator with fail safe switch and a 5.1V step down lead between the gyro and tail servo.

The eCCPM was relatively easy to set up using my 14MZ radio and I was able to get -10 to +10 degrees of pitch for my normal and idle-up modes and -10 to +13 degrees for my throttle hold mode. Click here to download my 14MZ setup.

Engine was an OS91-SZH with Hatori 938 tuned muffler. I replaced the fuel clunk with a fuel magnet and also fitted a Thunder Tiger header tank. Then engine had been run in a previous model and produced great power so there was no need to run it in. Only a few minor mixture adjustments were needed.
 

Flying:

Initial hovers showed the model to be incredibly stable and smooth with a very low head speed. Vibration from the OS91SZ was kept to a minimum with the nylon engine mountings doing their job. Fast forward flight showed the models potential with that streamlined canopy cutting through the air cleanly. Increasing the head speed unleashed a hugely capable model, lightning fast collective and pin sharp cyclic made the model incredibly predictable with very high performance. Needless to say I had a smile on my face for the entire flight. Two years of waiting and I finally got my hands on one - Fantastic!
A few teething problems did show up initially however. The first was the loss of all four engine mounting bolts on one side. I had missed tightening them up after aligning the engine - oops! These were quickly and easily replaced and it was soon back in the air. The second problem was that I noticed one of the bolts holding the flybar carrier had come out during flight. Luckily the other was still in place and tight. The head is pre-assembled at the factory so I was surprised to see this happen! The bolt is very short being an M4x6 socket head so I had to file down a suitable bolt as a replacement and fit a bearing shim. I added plenty of loctite and also checked the other side to make sure it was tight. If they are going to supply parts pre-assembled they should be put together properly or not at all!

Replacement parts should hopefully be easy to obtain once initially rolled out and not too expensive. Listed below are a few retail prices of common spare parts.

The model definitely seems to have taken a great deal of strong points from other helicopters and combined them together into one machine. For someone looking at moving into a larger 90 class model I would certainly recommend it as the next step, it's good value for money and is an extremely capable machine. It will certainly be nice to see something different from all the Raptor 90's flying at our club and all the fun-fly's around the country.

Should I get rid of the other Raptor 90 and get another one..... we'll just have to wait and see if they bring the Synergy N9 SE out!

Helicopter Specifications

Synergy N9 Helicopter
OS91SZH engine with Hatori 938 tuned muffler.
Wildcat 30% Nitro Youngblood Helimix fuel.
Throttle Jockey Rev Max.
Futaba digital 9255 servos for collective and cyclic.
Futaba digital 3152 servo for throttle.
Futaba GY601 gyro with digital 9251 tail servo.
Futaba 14MZ with Futaba R1054DPS 2049 PCM G3 Receiver.
Radix 710mm carbon fibre main blades.
SAB 105mm carbon fibre tail blades. (supplied with kit)
SAB 25gram carbon fibre paddles. (supplied with kit)
Duralite 4000mAH Li-Ion 2S2P battery pack.
Duralite 6V heavy duty regulator with failsafe switch.
Duralite 5.1V step down for tail servo.
QuickUK receiver protection case.

* syn·er·gy (snr-j) n. The interaction of two or more people or forces so that their combined effect is greater than the sum of their individual effects.