Sariel.pl

Model of a modern French main battle tank. Features advanced independent suspension with adjustable ground clearance, gearless drivetrain, remotely rotated turret and commander’s gun, remotely elevated main gun, and an onboard wireless live feed cam.

Datasheet:

Completion date: 17/08/2009
Power: electric (Power Functions)
Dimensions:  length 58 studs (including barrel) / width 26 studs / height 22 studs (plus aerials)
Weight: 2.48 kg
Suspension:  full independent with adjustable ground clearance
Motors: 4x PF Medium, 2x PF XL

I have a special liking for the tracked vehicles, and especially for modern tanks which happen to be the most advanced tracked vehicles ever built. This is why, having built my last tank nearly a year ago, I was looking for a modern machine that would make a nice model. I wanted something similar to the previous model, the Abrams M1A2 tank, but smaller, lighter and more mobile. Since the Leopard was out of the question (I wouldn’t feel comfortable building a German tank), and the Merkava has an unusually shaped turret that would be difficult to model, I decided to build the Leclerc – a very good and distinctive example of today’s high-tech tank.

If we lay aside the popular jokes on French tanks, the Leclerc is a fairly outstanding and impressive machine. It was build for a very interesting reason: because none of the world’s tank lived up to the expectations of the French Army. As one may anticipate from that, it is in many ways different than earlier main battle tanks such as e.g. Abrams, and very likely sets standards for the future constructions.  There are differences in almost every aspect of its construction: for example when it comes to the defence, Leclerc’s design focuses strongly on the active protection. The tank is protected passively by a modular armour similiar to the one used in Leopard 2, but there are two layers of active protection being currently developed and scheduled to be put into use around 2015: the ‘soft’ layer is capable of jamming computer systems of the incoming missiles, while the ‘hard’ layer shoots down any incoming large-caliber projectiles. Both layers are supposed to be fully automated, with the latter one being capable of shooting down projectiles coming from any direction in time intervals as short as 0.6 second. Even Leclerc’s armament is unusual: instead of Rheinmetall 120mm cannon present in vast majority of modern tanks, it uses longer French-built GIAT 120mm cannon along with a custom French-produced ammunition and an automatic compressed air fume extraction system instead of the usual bore evacuator. The tank’s turret is built around an autoloader system designed specifically for Leclerc, which provides an impressive performance and at the same time allows to avoid many problems usually present with the standard autoloader systems. The most impressive things are many high-tech upgrades scheduled for the Leclerc: those include the aforementioned two layers of the active protection, but also multipurpose armour upgrades, the anti-missile decoys deployment systems, thermal signature reducers, and – probably the most impressive of all – Stealth armour kit.

The construction of the model started with a new suspension concept. I was happy with the performance of the independent suspension used in my Abrams model, but I wanted to make it even more realistic. In order to achieve it I have removed the most unrealistic element, the central tread wheels , and I fitted all the road wheels with thin full rubber tires. Thus the tracks have no solid point of contact with any road wheel whatsoever, and are kept in place only by the road wheels, without any use of the tread wheels which are commonly used in the official Lego sets. At first it seemed an unreliable solution, but it proved to be perfectly reliable – I had less slipped track cases with Leclerc than I have had with the Abrams, and they all happened only because the tread links came apart.

It was obvious from the beginning that the model will make use of the new 8878 rechargeable battery and of the PF speed control feature. It meant two things: that it will have plenty of internal hull space available, and a very simple drivetrain. I have eventually limited the drivetrain to just two short axles connecting motors directly to the respective drive wheels – with the speed control feature nothing more was needed to allow the tank to make turns at any angle, and it seemed to blend power with speed in a promising way. Moreover, such a drivetrain was extremely efficient and durable, since not a single gear was used.

With a lot of internal hull space at hand, I wanted to try an idea of using the independent suspension to adjust the ground clearance. It was achieved by mounting upper tips of all the shock absorbers on lengthwise liftarms, which were moved higher or lower by two coupled pairs of very short levers. That solution worked very well in the early construction stage, easily providing two studs of difference in ground clearance, at which rate the tank was actually able to sit on the ground. It was also possible to change ground clearance at any position, at any moment, even while driving, and the tank’s suspension remained fully functional all the time. The efficiency of this system, which took almost half of the internal hull’s space (there were 4 sets of worm gears all coupled together), was eventually severely crippled by two factors: firstly, the length of the tracks which was limited. The tracks weren’t, obviously, elastic, so their length remained the same as the suspension was raised or lowered. It left a small margin for differences, as the tracks couldn’t be too lose or too tight, and so the range of ground clearance adjustment was limited to approximately single stud. The latter factor was simply the model’s weight, which proved larger than expected and heavily loaded the mechanics of the ground clearance adjustment system. Even though the Leclerc was still much lighter than Abrams, its suspension was loaded a bit heavier because it consisted of just 12 sets of road wheels compared to Abrams’ 14 sets.

The remaining hull space was used to house the battery (in front of the hull, with a small access hatch in the armour under the front part of the turret), three IR receivers (located next to drive motors, partially below rear part of the turret) and a PF Medium motor controlling the turret’s rotation. The last solution was unusual for my tank models, as the previous ones had this mechanism housed inside the turret itself. It made the turret’s internal structure a lot simplier, which was important to me because I wanted very much to model its distinctively flattened silhouette. Thus, the turret ended up housing two PF Medium motors, first of which was used to elevate the main gun. The elevation system used a single linear actuator, much like in the Abrams model, except this time it was located in a central position to make the main gun’s barrel more stable. As for the latter PF Medium motor, I initially intended to use it for a main gun recoil system, an improved version of the one used in the Abrams, but I have eventually decided not to make these two models more similar to each other than they already were. It left me with just a few possible options to use the extra motor, so the motor was eventually used to make a ‘turret in a turret’, that is to rotate commander’s gun, which is a nod towards the realism as the real Leclerc has this gun controlled remotely from inside the tank. Thanks to that, there was a lot of space left inside the other side of the turret, which I have used for something I wanted to use already in Abrams – an onboard live feed camera showing forward view from the turret. I have used a simple micro industrial surveillance wireless camera, exactly the one used much earlier in my Moon Rover. It fit inside the turret very well, and I was particularly pleased with the sound recorded from inside the model – the sound of moving tracks seemed more realistic than I could have ever imagined.

The model enjoyed a fairly good reception. I didn’t really like its aesthetic side which seemed too much like that of the Abrams model, but I loved the performance provided by the powerful drivetrain and the sophisticated suspension system. It seemed to have all the impressive power of Abram’s drivetrain, but moved much more swiftly and fluently. It was my fastest tank model at this weight and the first one to use Power Functions speed control feature.

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