Liebherr R9800 Excavator

Another LEGO excavator?

Yes, but this one is the replica of the largest backhoe excavator ever built! Let me introduce the Liebherr R9800. Weighing around 800 tons, 10 meters high, with a bucket capacity up to 47.5 m³, this steel monster requires two V-16 engines to be moved, for a total power of almost 3 MW.

The 1/50 scaled LEGO version nearly fits with the minifigs size (They are actually a bit too big, but it is more fun to have a LEGO driver in it!).

I designed it mainly on LDD but I checked the kinematic and the rigidity of the assembly with real bricks to be sure it is ok. Unfortunately, LDD does not contain all pneumatic parts. I did what I could to model them, but none of the hoses are represented although they are integral parts of the design.

The boom, the stick, the bucket and the access ladder are actuated with pneumatic cylinders. The control valves are on the top and two pumps are hidden inside the upper carriage. They are settled horizontally and can be actuated by pressing the ventilation grids on the right side of the excavator.

The LEGO cylinders don’t have the exact length I needed, so to keep the arm kinematic, I had to make some compromises with the positions of their connection points on the boom and the stick. Sorry for the authenticity of the replica!

But as in the real excavator, the tracks are tensioned. Indeed the front wheels are sliding in the sides and in this case, springs are pushing them forward. The track then always keeps this nice shape.

Finally, the building experience is really exciting. The model is meant to be assembled just like the real excavator would be, with very realistic shapes for all the structural parts, especially the slewing platform which is the base of the upper carriage.

I can’t wait to glue the official LEGO sticker “9800” right in the middle of the counterweight ;)

If this is also the case for you, don’t hesitate to support this project!

Thank you in advance.