Hellbender
Model of my favourite vehicle from the Unreal Tournament 3 game. Features 4×4 drive, full suspension, pneumatic rear differential lock, rotating front & rear turret, lights and custom stickers.
Datasheet:
Completion date: 24/03/2009
Power: electric (Power Functions) / pneumatic (fed from internal electric compressor)
Dimensions: length 46 studs / width 29 studs / height 30 studs
Weight: 2.35 kg
Suspension: front – independent / rear – live axle
Motors: 3 x PF Medium, 1 x PF XL
Pneumatics: a single circuit with an autovalve fed from a dual-pump internal compressor
Being an ardent fan of the Unreal Tournament series, I have finally decided to join two passions and build a model of my favourite UT vehicle. Which is Hellbender, underestimated by many, but absolutely lethal if used properly. It was also an opportunity to test a suspension I have developed with Truck Trial races in mind, as well as the 3 studs wide differential lock mechanism I have recently published.
The model is certainly not 100% accurate, as the original vehicle was quite challenging to reproduce. It is, however, entirely functional and fitted with 4 motors total. Power is delivered from two battery boxes, not because of some particularly high energy consumption, but because it turned out to be optimal to locate the battery box on the side, so I have used two battery boxes, one counterbalancing the other. The 4×4 drive is powered by a PF XL motor, and the steering is operated by PF Medium one. Another Medium motor rotates two turrets synchronously. The third Medium motor drives a dual-pump internal compressor via an autovalve, thus controlling the differential lock mechanism in the rear axle. As the rear axle is floating and quite complex already, I found it to be an optimal solution – thus, almost entire pneumatic system is located inside the hull, and there is only a sinle small pneumatic cylinder with two pneumatic hoses in the rear axle.
As for the off-road performance, the model certainly suffers from a short chassis and perhaps too complex rear axle. The short chassis was the reason why the drivetrain is complicated, with steering system located behind the front axle, and the drive being transferred to it from the front. A single, common driveshaft located in the center of the chassis would certainly perform better, as it is a popular solution in the Truck Trial vehicles. The rear axle, on the other hand, has its differential mounted not steadily enough because of the lock mechanism, which results in the gears’ tendency to snap. The model performs well on the floor, but has difficulties with even easy obstacles. It is, however, an interesting study of how the independent suspension based on the 8297 set’s components performs.
The model was presented by me at the official UT3 forums, where it has been acclaimed by some members of the Epic staff.
I know it may look like a real challenge but the Leviathan with the “siege mode” when the main cannon come out would be sick.
BTW your super tank T 28 was jaw dropping!
@legokid
It locks the rear differential.
I dont understand what the pneumatic is for?
i like how you made the steering rack wrap around the differential for the front axle. clever solution
@Sariel
ohhhhh I see, thank you!
I love UT too, I am going to get the UT3 soon!
@Boris
You can find a scheme of the lock in the Ideas category. It’s really simple, it basically locks together both half-axles that come out of the differential. Thus the differential’s ability to well, transfer drive at different speeds to those half-axles is disabled, and the differential works like a regular gear.
I am speechless, but I really wanted to ask you one thing, is there a separate project on the diff lock, or if there isn’t, can you just roughly explain how does it work?
@Sariel
Yeah!… now that you mentioned it, remembered to have seen it some time ago in the LDraw POTM page. It won the POTM-BP last October. :-[
http://www.ldraw.org/index.php?module=LdrawMOTM&func=index&categoryid=4&yearwon=none&author=none
@Fernando
He did one. I just got it today.
@Sariel
Wouldn’t get surprised if finding that Philo was about to do one… 😉
Thanks! I’d love to reproduce the functioning of the lock with the SR 3D Builder, if I lay my hands on a proper model of the new differential.
Another awesome construction Paul!
Congrats.
Would have loved to see a close-up of the diff locking mechanism, working! Not that it isn’t understood how it works, from the previous post where you presented it.