Around this time two years ago Goblin unveiled a brand new concept model in Italy at Goblin Day 2018. The model was called the “Kraken” and it was advertised as a brand new 700 Heli design from SAB. After the release we heard very little about this helicopter until the middle of February 2019 when SAB announced they would show it at the Rotor Live show in Germany. It was one of the highlights of the new show garnering a lot of attention.
With the new Kraken, SAB Heli Division did it again! With many original solutions which never have been seen in the RC Heli world, SAB managed to achieve this by listening to the feedback from its customers and pilots. The Kraken has been redefined in a number of ways, offering fans of the Goblin Helicopter line “more of what they love.”
The new fully enclosed power train is perhaps the most notable change compared with other Goblins. You will notice this immediately as soon as you open one of the smaller boxes inside the Kraken box. However, there are other great improvements compared with the rest of the Goblin range.
The new Goblin Kraken is packed with upgrades, for example, the independent belt shafts for the transmission and the tail which makes the build and the maintenance much easier. It also has a new and improved Ultra-light, 7075 aluminium alloy, rotor head, Ultra-light Tail case with quick tail fin replacement, similar to the tail fin of the Goblin Thunder T-Line.
All these new upgrades implemented on the Kraken does not only make it easier then ever to build and maintain but, but it also makes this machine much more crash durable and all of this with an airframe weight of just 2680g.
At first glance, the new Kraken doesn't look at all like any other Goblin 700 sized model. That is a remarkable achievement, considering the current Black Thunder series of 700 sizes all follow the same design.
SAB is taking this model to another level redesigning the Kraken from scratch but off course including many original solutions of the Goblin range.
The Kraken is really a beautifully designed machine, inside and out. Put aside the F3C jokes, and just look at it: there isn’t just another Helicopter that is this precisely engineered. The full body and boom design, with integrated frames is instantly recognizable. The boom detachment system for improved crash durability is a really nice feature, and the whole thing is ridiculously amazing in flight. The Kraken allows you a very wide range of dampening setups to ensure that this model adapts to all the pilots. The dampers are composed of 3 O-rings (that defines the rigidity) and a techno polymer damper (that defines the maximum possible movement of the spindle). Using different O-ring and dampers you can get different responses of the model.
Inside, you can find every inch of this machine masterful engineered by SAB. There are not a single thing that SAB didn’t think about. The blade grips are made from 7075 T6 aluminium, and the blade grip arms are made from 6061 T6 aluminium. This way when you have a crash you can bend the blade grip arms, but you will never (depending on the crash) damage the main blade grip. Using a M4 screw makes it very easy to replace just the arm, unlike the previous HPS rotor head that had the screw from the inside.
The power train supports 3 shafts: Main shaft to the rotor head, shaft to the motor and shaft to the tail. The one-way system inside the module is very reliable, suitable for transmitting any power, it does not require maintenance and is very strong in case of a crash. It is possible to replace the main shaft by removing just one single screw. The transmission module is assembled and verified by SAB so it's ready to be used out of the box. My favourite little gimmick included? Since SAB wanted to get as much as possible rid of the cables on the Kraken it includes a very clever solution for it. The included wire support makes it very easy to guide the wires on the main frame.
The full body and boom design with the integrated frames are one of the new highlights compared to the other Black Thunders. As usual SAB decided to go for high-end materials, the main frame uses Carbon Fiber. At first, it looks weak, but after installing the new power train its really reinforced. In the front of the Kraken we have the ESC support, a composite tray with sacrificial plastic insert with edges covered in rubber for wires protection.
The new redesigned ultra-light tail case with quick tail fin replacement uses a 3 mm full carbon side plate that is 23 grams lighter than the Black Thunder tail case. It has a very simple, strong, reliable and durable design.
The plastic battery tray is also a redesigned version of the ones we seen on the Black Thunder T-line. On the Kraken its much wider and its mounted to the frame upside down, it comes with all you need to install your batteries with a carbon fiber battery protection, double-side tape and the battery straps.
The landing gear on the Kraken is similar to the one from the Kyle Stacy Goblin 700 or the Black thunder sport. We think it’s a perfect landing gear because it can resist very hard landing and skid bumps.
It’s very well explained in the manual were to put which glue or thread lock but we always recommend those screws threaded into metal to apply a little thread lock to the screws. It is very important to use it well to prevent stripped bolt heads or broken screws. Its sufficient to apply a little on the tip of the screw (aprox. 1mm).
Some parts are factory pre-assembled. We always check everything to ensure the correct assembly and if thread lock is applied, but to be honest with hundreds of Goblins build, we never found any mistake on the pre-assembled parts.
It's time to close the carbon fiber frame where all the mechanics are installed including the servos, in this build we decided to use the well proven Brushless DS8002HV BK Servos for cyclic. We highly recommend to use the original servo horns from SAB (HA050-S or HA051-S) to get perfect geometry and to avoid servo damage in crashes. The anti-rotation guide is now on the front servo mount.
The Z60 main pully is together with the front tail belt pully the only two gears that are visible on the new Kraken. All the other transmission gears and parts are enclosed in the new power train.
Unlike the other 700 Goblin’s the new Kraken doesn´t have a tail belt idler or any other system to control the tension of the tail belt during flight. In our opinion it's nice to see that the Kraken doesn’t need one. Although the manual clearly says how to mount it correctly on the Goblin, we have seen many pilots mounted it the way around and struggle to figure out how to put the spring tension.
Talking about manuals… As we all know, SAB manuals are among the bests I've seen with very clear and detailed drawings. Everything in the manual is detailed, like for example on the motor mount section they clearly give us all the information we need. Including the maximum size and length of the motor shaft up to all the different ratio configurations.
It is very important to choose the correct ratio that maximizes efficiency depending on the motor, pinion and RPMs we want to fly. As usual, and thanks to Kontronik for the support, we opted for a Kontronik Pyro 750-56L Competition paired with a Kontronik Cool Kosmik 200A. We used the pinion included in the kit, a 21T pinion that gives us a ratio of 10.4:1 and max RPMs of 2250 at 80% throttle curve. This is perfect and recommend by Kontronik to assure a correct function of the Governor.
The tail is one of the characteristic items of the Goblin. The boom has nothing to do with a traditional tail boom. SAB manufactured an oversized high-tech composite Carbon and Airex sandwich tail boom which comes factory painted in the same design as the canopy and the low side frames. It is rigid enough, so no need for tail boom supports. Another great detail from SAB is the way it's fitted onto the frame with the aluminium boom block support, 3 plastic M10 bolts and 3 plastic M10 nuts. This ensures that boom construction works as a fail safe in case of a crash. The kit includes a special G10 tool for this. The goal of this anchoring system is that when you crash the screws breaks and saves as much as possible the tail assembly.
For the Tail servo we decided to go in the same Brushless line and used the BK Servo DS8005HV servo. This servo is mounted upside down in the lower part of the boom. More or less in middle of the boom in the lower part we can find the tail push rod guide. The tail push rod is made of carbon fiber. A tip when building this model is to glue them together as one of the first steps, this ensures that the glue is dry and hardened enough by the end of the build. We recommend to use 5min Epoxy Glue.
The kit comes with all you need, including an extension cable for the tail servo to ensure when you crash and boom detaches from the main frame, you don’t break the servo cable. Small details like this are the things you really appreciate when you are building your new machine, your new Goblin!
The kit is presented in the usual professional manner. When you open the box, the first thing you will find a SAB work bench towel “nice touch” followed by the visually appealing manual printed in full colour and a product card with the serial number to register your kit online via www.goblin-helicopter.com. The rest of the parts is distributed in black boxes filled with form foam and all loose parts are nicely classified in numbered plastic bags. The canopy and boom come very well protected in a massive foam insert in side two other bigger boxes.
All the CNC parts come protected with foam trays to avoid scratching. The rest of the parts all well marked in plastic bags. They are numbered and correspond to the assembly procedure on the manual.
A true unboxing experience that you will expect from a brand like SAB!
The basic setup of this model used in this review is the following with a V-Bar Control and a V-Bar NEO flybarless system with PRO Version.
Since this was not the first Goblin 700 we have ever build, we really know the settings that both Goblin and the pilot want as a starting point; although we knew it needed little tweaking since it comes with an overall new mechanics. We tested various settings and this is how we liked it the most. On the main rotor settings, we use an Expo of 20, Style is set to 98, Rate++ to 124 and a head gain of 51. For the tail we use expo at 20, Rate++ at 114 and tail gain is set to 50. The settings are always a personal choice but this is the way we liked the model the best. We used a Kontronik Kosmik 200A with the internal governor enable (Mode 4) so we can set 3 head speeds using straight linear throttle curves. The correct ratio as previous explained with a 21T pinion and a 560KV motor is 10.4:1. With this setup we can reach a maximum head speed without governor overturn (80%) of approx. 2250RPM, this was the range we wanted to fly this helicopter.
The throttle output is set the following way. The motor has 560KV and we used a 12S setup with Gens Ace 5500mAh 45C Ultra packs and the included 21T pinion.
Throttle output |
|
|---|---|
| Flight mode | Output |
| Bank 1 | 60% |
| Bank 2 | 75% |
| Bank 3 | 80% |
| Flight mode | Approx. RPM |
| Bank 1 | 1750 RPM |
| Bank 2 | 2050 RPM |
| Bank 3 | 2250 RPM |
Pitch curve have been set in all Banks to -13 at low stick, 0 at mid stick and +13 at high stick as a personal preference.
Initially we programmed in normal flying mode 1750 rpm. During hovering the Kraken remained very stable without any wobbling even at this low RPMs. With these RPMs the behaviour of the helicopter is very smooth and predictable.
We switch to bank 2 raising the head speed to about 2050RPM. We started doing some fast forward flying and the heli traced a perfect straight line without any strange tendencies. We really love the smooth sound coming of the Kraken. Thanks to its design and colours, it has fantastic visibility in flight in all directions.
But we all know that a Goblin and the pilot like higher RPMs so we switch to bank 3. The sound changed completely, now it really started roaring with a perfect flight behaviour at all time! We started with some fast manoeuvres like hurricanes, chaos and some stress test to the machine to see what’s capable off with some tic-tocing manoeuvres like wheel of fortune and the Time machine and the helicopter held really well during all these manoeuvres and was really accurate and powerful.
The cyclic response is perfect in our opinion. The flight characteristics offered by the brand new and much improved Ultra-light, 7075 aluminium alloy highly adjustable rotor head are very good with a different feeling, then flying with the HPS rotor heads on the Goblin Black Thunders. In my opinion the new rotor head is the perfect mid-way between an aggressive and smooth, precise flight. The Kraken is extremely agile and fast with a very aggressive flying style you can feel the rigidity of the model in flight. The tail performs well in all kinds of manoeuvres with Piro’s and reverses. The dynamics with the V-Bar Neo is perfect.
At the end of the manual includes a sheet named (MAINTENANCE). Here SAB explains some of the key points of the helicopter where you should pay attention. Although helicopters are prepared today for more radical 3D all have wear and require maintenance. Sounds like a good idea that SAB includes a sheet with Tips & Tricks.
As we were reviewing the Kraken, I realized that I could have just re-printed our 2011 Goblin 700 review, and no one would have really noticed because the results and feelings are so similar: SAB made a beautiful helicopter with a remarkably advances never saw in RC Heli world before once again, and when you build yours, and you switch the idle up, you unlock the potential of this machine, and you will discover a flight that takes hold of you.
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Technical specifications
Recommended components (not included)
Delivery
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Upgrades Included
What's still needed
Manufacturer: SAB GOBLIN
Web: www.goblin-helicopters.com
