LEGO Technic Liebherr R 9800 Excavator 42100 Building Kit (4,108 Pieces)
Price as of August 2026
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Our Review
LEGO Technic's 42100 Liebherr R 9800 Excavator is a 4,108-piece motorised build with app control and working functions. It's aimed at older builders and anyone who likes their models to actually do something. Here's how it holds up.
Pros
- Motorised functions and app control make it genuinely interactive
- Huge, impressive finished model with real mechanical complexity
- Teaches gearing and mechanism concepts as you build
- Battery boxes are part of the design, no fiddly add-ons
Cons
- One of the pricier Technic sets at around $450
- Complex build that's not suited to younger kids
- App-controlled motion is slow, more demonstration than play
- Large and a little unwieldy to store
Detailed Analysis
A model that moves
The draw here is that the excavator actually functions: motors drive the tracks and the digging arm, controlled through an app. That makes it more engaging than a static display for people who like mechanisms, and it's a real lesson in how gears and motors combine. The tradeoff is that the movement is deliberate and slow rather than playful.
Who it's really for
This is a set for teens and adults who enjoy engineering, not a toy for small children. The build is long and involved, and getting the most out of it means tinkering with the app functions. For the right person that complexity is the whole appeal; for a casual gift it may be too much.
Final Verdict
One of the most rewarding Technic sets if you value function over pure looks. It's pricey and complex, but the working motorised model is a genuine highlight for engineering-minded builders.
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