Adult Building Sets
LEGO Technic Liebherr Excavator R 9800 Review: The Most Mechanically Serious LEGO Set Ever Made
- Brand:
- LEGO Technic
- Ages:
- 18+ years
- Updated:
- 2026-07-06
The verdict
The single most impressive LEGO Technic set on the market for a serious adult builder — buy it specifically for the mechanical functions, since the price only makes sense if you'll actually use the motorized features.
Pros
- 4,108 pieces with genuine hydraulic and pneumatic-style functions across the boom, bucket, and rotating cab
- App-controlled motorized functions via LEGO's Control+ system, not just manual mechanisms
- Widely regarded as one of the most technically ambitious LEGO Technic sets ever released
- Extensive functional detail — working outriggers, second cab, and a fully rotating superstructure
Cons
- Very high price and multi-day build time even for experienced adult Technic builders
- Requires separately purchased batteries for the Control+ motorized functions, an easy detail to miss before buying
This review is based on LEGO's published Technic Control+ specifications for set 42100 and the consistent pattern in buyer and reviewer feedback: near-universal praise for functional ambition, positioning this as a flagship rather than a typical set.
A genuinely different tier of Technic engineering
Most Technic sets have one or two working functions. This model has a rotating superstructure, extending outriggers, a working boom and bucket, and a second cab — all app-controllable — which is why it's consistently cited as a flagship rather than a standard release even within LEGO's own Technic line.
Who it's for
Specifically for serious adult Technic builders who want the most functionally complex LEGO model available and are willing to pay flagship pricing for it. Not a reasonable first Technic set for a beginner.
Frequently asked
- Are batteries included for the motorized functions?
- No — the Control+ motorized functions require separately purchased batteries, which is worth budgeting for before buying since it's not included in the box.
- Is this a good first Technic set?
- No — this is one of LEGO's most complex Technic sets ever released. First-time Technic builders should start with a smaller, simpler set before attempting this one.
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