LEGO Robotics Invention System, Version 1.5
Set #9747 · 1999 · 731 pieces · Substantial build
Set Details
- Set Number
- 9747
- Name
- Robotics Invention System, Version 1.5
- Theme
- Mindstorms
- Year
- 1999
- Pieces
- 731
- Complexity
- Substantial
- Build Time
- 2-4 hours
- Ages
- 10+
- Type
- Educational
About LEGO Robotics Invention System, Version 1.5
LEGO Robotics Invention System, Version 1.5 (set #9747) is a large, detailed build with 731 pieces from the Mindstorms theme, released in 1999. The Mindstorms line features programmable robotics kits combining bricks with sensors and motors. At 731 pieces, this is a substantial-level build with an estimated build time of 2-4 hours, suitable for ages 10+. This set dates from the 1990s, a turbulent decade when LEGO launched Star Wars and Mindstorms while navigating financial difficulties.
Set Highlights
- 731 pieces at substantial complexity — a 2-4 hours build.
- Compatible with all standard LEGO sets — bricks extend naturally into other sets you own.
- Play-focused build with interactive elements designed for 10+ builders.
- Classic-era set from 1999 — no longer in production and popular with collectors.
Who Is This Set For?
Gift for Ages 10+
The substantial difficulty makes this accessible without being trivial — a well-matched gift for LEGO fans in the 10+ age range.
Weekend Build Project
731 pieces with an estimated 2-4 hours fits comfortably into a focused afternoon or weekend session.
Expanding a Mindstorms Collection
A solid addition for collectors building out their Mindstorms shelf. Introduces parts and builds that complement other sets from the same line.
Build Tips
A five-minute sort by color or piece type before starting saves time hunting for specific bricks mid-step.
Follow the numbered steps in sequence — structural elements early in the build support everything that comes after.
Keep the instruction booklet after building — it's the most reliable reference for disassembly, cleaning, or reassembly after storage.
Finding Instructions
Building instructions for LEGO Robotics Invention System, Version 1.5 (#9747) are available as a free PDF on LEGO.com. You can also upload a photo of this set to LegoFinder to identify it and access the instructions directly.
Robotics Invention System, Version 1.5 FAQ
Related Reading
More Mindstorms Sets
See all Mindstorms →
Also Released in 1999
All 1999 sets →Similar Build Difficulty
Sets at roughly the same piece count and complexity tier — different theme and year, but a similar build experience.
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