The MT85 was a prototype of a 85t truck built by Atlas Copco, which could have become the world’s largest articulated underground mining truck. It was presented in MINExpo Las Vegas in 2012 but never went into production since.
The highlights of this concept were the large payload (85t) and the capability operate in standard 6x6m gallery despite its dimensions (3,4×3,5x14m) thank to an excellent maneuverability : The truck is articulated at a maximum angle of 40° and has a rear steering axle.
Aaaaand… that all. There is very limited information and picture of this truck. Even Atlas-Copco website no longer has a dedicated page of the MT85.
The MOC is obviously based on the design of the initial prototype. We have so a 6×6 low profile articulated truck.
From forward to rear:
On the left side of the head can be found a tiny cabin with an opening door and a seat. The center is mostly occupied by the engine hood. It is not very detailed but hides two of 3 motors used in this truck (refer to §functions).
Forward axle is rigid (no suspension) and equipped with a differential.
The articulation is built around a steering ball joint, it accommodate the axle for steering and propulsion.
The technical part of the truck is located at the front part of the rear chassis. Here are installed the actuator for steering and the motor for tilting the tipper.
Rear part of the chassis accommodates the two rear axle (1 fix the other steering) both equipped with a differential. The tipper support is fixed at the rear end of the chassis.
The tipper is a separated part not assembled to its support; it is a technical choice here to ease the access below. It has a low profile like on the real truck and a rear opening door.
By searching some picture to write this review (of course after finishing photos and videos), I noticed that the front hood is actually not symmetrical, the right part is much larger and accommodate some air filters (see below, source: Socalearthmovers.com )
There are only 3 functions in this truck.
The first one is the propulsion. It is performed through a PF-XL motor installed in the nose of the truck. The reduction is 3:5 and it powers all 6 wheels. The articulation as accommodated via the use of a universal joint.
Second function is the steering, divided in two part: articulation and rear axle both powered by the same PF-M motor installed above the forward axle. The articulation is actuated by two mini linear-actuators. Unfortunately the 40° angle of the original prototype truck couldn’t be reached, but the truck remains maneuverable enough. The steering of the rear axle is actuated by a third mini linear-actuator installed under the belly of the truck. It slides a series of beam back and forward that creates the rotation of the rear axle.
Third and last function is the tilting of the tipper, combined with the opening of the rear door. Tilting is actuated by a single Linear-actuator powered by a PF-M motor (hidden in the left side of the truck. It is powerful enough to lift the tipper even when fully loaded with bricks. The opening of the door is “simply” done by two string link to the chassis. When the tipper is lifting up the string pull on the door and open it.
All the functions are powered using a single Buwizz brick. For this MOC the it was the best compromise between the number of function (4 port available, only 3 used) and the room available. The Buwizz is located in the right side of the truck between front and middle axle. A custom profile command is used for this truck, but no pre-programmed functions.
Curious about Buwizz? Find more information at : https://buwizz.com