K2 Black Panther

Model of world’s most modern tank. Features a suspension system with adjustable ground clearance, rotating turret, elevated main gun, firing mechanism and lights.

Datasheet:

Completion date: 22/03/2013
Power: electric (2 x 8878 rechargeable battery)
Dimensions: length 60 studs (not including the barrel) / width 26 studs / height 20 studs (in lowest position, not including antennae)
Weight: 2.484 kg
Suspension: torsion bars with adjustable ground clearance
Propulsion: 2 x PF XL motor geared 1.6:1
Motors: 2 x PF XL, 2 x PF L, 2 x PF Medium

The K2 Black Panther tank is the successor of South Korea’s first indigenous main battle tank, the K1. While the K1, which has entered service in 1987 is still a fairly decent tank by today’s standards, The K2 was designed as a cutting edge of the modern military technology. It is the world’s second most expensive tank, right after the French Leclerc tank, and the most advanced one, especially if we take into account its extensive development program, and the fact that it has not yet officially entered service. The Turkish Altay tank, which is currently under development and is widely considered a very modern design is heavily based on K2, and is being created as a direct result of a technology transfer from South Korea. It is, however, less advanced and considerably cheaper.

While the K2 may appear as a combination of the Abrams/Leopard tanks, it is far more advanced. Some consider it a part of a brand new generation of tanks, and it surely demonstrates what the tank technology will bring in future. Some of its features include:

120 mm/L55 Rheinmetall main gun, identical as in the latest Leopard version. K2 is the only tank in the world that can be refitted with a 140 mm main gun with minimum modifications.
fully active suspension, with each road wheel controlled independently. This enables the whole tank to “sit”, “stand up”, “kneel” and tilt in any direction.
advanced autoloader, similar to Leclerc’s one, capable of loading a new round in 1-2 seconds. Under optimal conditions, the K2 can fire new round every 3 seconds.
complex electronic systems that allow a single crew member to control the entire armament, enable tracking of multiple targets at distance up to 10 km using the radar system present on the frontal arc of the turret, including comparing targets with other friendly vehicles using data link, to prevent redundant target engagements.
fire control system capable of delaying a shot if the chassis encounters an obstacle as the trigger is pulled. The system automatically fires the round as soon as the main gun is realigned.
primary munition: unique tungsten penetrator rounds, with a core that is capable of self-sharpening rather than deforming during armor penetration.
secondary munition: unique type of a fire-and-forget rounds, which is fired from the main gun at a mortar-like trajectory. Upon reaching designated target area, it deploys a parachute and seeks for targets autonomously, or via remote control by the K2 crew member. Once target is acquired, the round launches a penetrator round which hits the target from above. That makes the K2 the world’s first tank capable of indirect fire, especially useful against hidden targets and allowing the tank itself to remain hidden.
the K2′s composite armor is capable to withstand a direct hit from a 120mm/L55 gun, that is the heaviest gun used in modern tanks. The tank also has a “soft armor” in form of electronics capable of detecting radar and laser beams in 360 degrees range, with the ability to warn the crew, establish direction of the threat, use radar jamming and special types of smoke screens and grenades that disrupt laser emissions and block optical, thermal and radar signatures.
the tank is propelled by a 1,500 HP engine, which gives it excellent mobility, similar to Leclerc’s. It can also cross rivers up to 5 meters deep using a snorkel, and it is combat-ready as soon as it resurfaces.

In addition to these features, the K2′s long development program includes:

installing a high-resolution terrain scanning system with a range of 50 meters in any direction, so that the suspension can be pre-adjusted on the fly.
installing a XAV, an unmanned wheeled scout drone that can be controlled remotely by a tank’s crew member
intergration of a hard-kill anti-missile system capable of shooting down incoming projectiles
replacing the conventional gun with an Electrothermal-chemical gun. ETC guns are a project somewhat similar to railguns, but with an electrically triggered plasma cartidges. They offer significantly more firepower and payload over that of conventional guns.

Here’s the K2 in action:

Click here to view the embedded video.

The model itself was inevitably a successor of a Leopard 2A4 model I’ve built back in 2010. Leopard was my first tank using torsion bars suspension, and it occurred to me back then that the bars can be rotated, thus allowing to adjust the suspension’s ground clearance. I have chosen to build K2 with this feature, as it is the world’s only tank with an adjustable ground clearance, but I have also decided to take my time, on assumption that the longer I wait, the more different the new model will be from the Leopard, and the more new LEGO pieces will become available, and with them – new possibilities. The K2 model does, indeed, make use of small linear actuators and L motors, both unavailable in 2010.

The model was suspended on 12 road wheels, each with 8L axle acting as a torsion bar. The inner ends of the bars were attached to a beam that connected ends of all the bars together, and which was moved back and forth by L motor with a large linear actuator. This system was independently doubled for left and right track, enabling the model to “sit”, “stand up” and to tilt left/right. Tilting forwards/backwards was not possible though.

Adjusting ground clearance should in theory require changes to the circumferences of the tracks, and I have been thinking about a mechanism that would move front sprocket wheels back and forth to prevent the tracks from becoming loose. It has, however, proved needless, as enclosing the tracks within the hull properly made sure they don’t come off even when loose. The model was perfectly capable of driving and turning even in the lowest position, and the suspension remained functional at all times. It drove a little slower when in the lowest position though, as the drive sprocket wheels slipped on the loose tracks occasionally.

The propulsion system consisted of two independent XL motors, each for one track, geared 1.6:1. The drivetrain was simple, efficient, and the model was a real pleasure to drive, with plenty of power and excellent suspension. I did not recall any other tank model that would be so enjoyable to drive.

The power supply consisted of two 8878 rechargeable batteries, placed on their sides across the hull, so that their fronts faced the tracks. It was somewhat inconvenient, because the access to the batteries wasn’t easy, but it allowed to keep the hull low. The hull was very densely packed, with the suspension and ground clearance adjustment system, with two L motors, each with a large linear actuator, with two batteries, three IR receivers, two XL motors with transmission and one Medium motor rotating the turret. The turret’s turntable was also installed within the hull, so that there would be more space available inside the turret.

- Load the Anti-Cat round!

The turret itself was a great challenge both mechanically and aesthetically. It had to be very low, so I installed one Medium motor inside it, together with a distribution gearbox that switched the motor between two functions. The gearbox was operated manually with a round brick on top of the tower, and the two functions were: elevating the main gun and firing.

The main gun elevation’s mechanism used a small linear actuator and a complex linkage to make it fit inside a limited space. It worked well, but the exceptionally large weight and length of the main gun’s barrel proved to generate a lot of backlash in it. As a result, the barrel was quite wobbly while driving.

The firing mechanism was relatively simple and used a Lego spring-loaded cannon, which was moved forth by another small linear actuator. During the movement, the moving part of the cannon would push open part of the front of the turret, and once opened, the cannon’s trigger would encounter a stopper, releasing the projectile. The mechanism required manual reloading after each shot and its range was limited, but it worked flawlessly and fit inside a very limited space.

On the aesthetic side, the problem with the K2 was that it’s a very new tank. It’s supposed to enter service in May 2014, and the information on it is severely limited. There are no blueprints, for instance, and most of the photos show development versions rather than the final production version. Eventually, I have decided to rely on a series of renders that became available shortly before I started to build the model. The model was not perfect aesthetically – the road wheels were somewhat too small, for instance, and there was a large gap between the turret and the hull (but there is also some gap in the real tank). My goal was to show how very flat the real tank is, as most of my tank models appear too tall to me. I might have overdone this, especially with the turret, which was extremely flat in my model.

In the end, I consider the K2 my best tank model up to date, ambitious both mechanically and aesthetically. It was enormously pleasant to drive, and, last but not least, it was designed as a part of a larger creation…