How many pieces are in the Robot Inventor?

Robot Inventor contains 949 pieces.

What age is the Robot Inventor recommended for?

This set is recommended for ages 10+.

When was the Robot Inventor released?

Robot Inventor was released in 2020.

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🏛 Mindstorms

Set #51515

Robot Inventor

The Robot Inventor set is a fantastic gateway into the world of LEGO robotics and coding.

Before you buy

Who it's for: Ages 10+ · Intermediate build Perfect for teens and adults interested in robotics and coding
Build: 949 pieces · about 4.5 hours Build time is an estimate.
Price: $359.99 list price · 37.9¢ per piece
Availability: Retired at LEGO

★★★★☆ 4.5 community rating from 32 ratings

Fans praise the set's engaging building experience and the educational value of coding robots. Some criticisms include the high price and the reliance on a tablet or smartphone for programming.

$359.99

Best Price

$323.99

You Save

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📝 Our Take

AI-assisted editorial summary, grounded in our LEGO database and public community discussions. How we use AI

The Robot Inventor set is a fantastic gateway into the world of LEGO robotics and coding. This set combines the fun of building with the challenge of programming, allowing users to create and control their own interactive robots. It's a modern take on the classic Mindstorms theme, updated for today's tech-savvy generation.

This set is perfect for kids and adults who are interested in STEM and robotics. The building experience is engaging, and the programming interface is intuitive, making it accessible for beginners while still offering depth for more advanced users. The five different robot models provide plenty of replayability and opportunities for customization.

Skip this if you're primarily interested in display models or have no interest in programming. While the robots are visually appealing, their primary function is interaction and play. Consider LEGO Technic sets for display or Boost sets for simpler coding experiences.

✨ New

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How does Robot Inventor compare to other LEGO Mindstorms sets? What programming languages are compatible with the Robot Inventor hub? Can I use LEGO Technic parts to expand the Robot Inventor models? What is the long-term value of retired LEGO Mindstorms sets?

🧱 Building Experience

AI-assisted build estimate, grounded in our LEGO database and public community discussions. How we use AI

🧩

949

Pieces

⏱

4.5h

Estimated Build Time

📊

Intermediate

Difficulty

👤

10+

Ages

Build Highlights:

Building five different robot models with unique functions
Learning basic programming concepts through a visual interface
Integrating motors, sensors, and the intelligent hub
Customizing and expanding the robots with additional LEGO elements

📈 Investment Analysis

AI-assisted investment analysis, grounded in our LEGO database and public community discussions. How we use AI

↑ Trending up since release

Investment Grade

⏳ Retired

The Robot Inventor set (51515-1) presents a mixed investment outlook. As a retired Mindstorms set, it benefits from the theme's enduring popularity and educational value. The rising price trend indicates growing demand. However, its high MSRP and the potential for newer, more advanced robotics sets to emerge could temper future appreciation. Investors should consider the set's condition and completeness, as the electronic components are crucial for its functionality and value.

Not Financial Advice: Content is for educational purposes only. Past performance doesn't guarantee future results. Full disclaimer

⚖ Compare Similar Sets

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Compared to older Mindstorms sets, Robot Inventor features a more modern and accessible programming interface. While the price is higher than some Technic sets, it offers a unique combination of building and coding. Consider LEGO Boost for a simpler, more introductory robotics experience.

📦 Parts Inventory

Official piece count: 949
Parts cataloged in this inventory: 129 unique parts, 949 pieces

Missing a piece? Check this set piece by piece, with look-alike colors flagged and element IDs for replacements.

Technic Pin Conne...

Part #: 10197 2× Black

Technic Gear 8 To...

Part #: 10928 2× Dark Bluish Gray

Technic Axle Pin ...

Part #: 11214 14× Dark Bluish Gray

Technic Beam 1 x ...

Part #: 11478 4× Black

Technic Panel Fai...

Part #: 11946 2× White

Technic Panel Fai...

Part #: 11947 2× White

Technic Beam 3 x ...

Part #: 14720 2× Light Bluish Gray

Technic Panel 3 x...

Part #: 15458 2× White

Technic Axle 5 wi...

Part #: 15462 2× Reddish Brown

Technic Gear 20 T...

Part #: 18575 4× Tan

Technic Pin Conne...

Part #: 18654 10× Dark Turquoise

Technic Pin Conne...

Part #: 18654 6× Black

Technic Pin Conne...

Part #: 18654 10× White

Technic Turntable...

Part #: 18939 1× Light Bluish Gray

Technic Driving R...

Part #: 18948 1× White

Technic Pin Conne...

Part #: 22961 4× Black

Technic Panel Cur...

Part #: 24116 2× White

Technic Panel Cur...

Part #: 24119 2× White

Technic Axle 3 wi...

Part #: 24316 12× Reddish Brown

Plate Special 2 x...

Part #: 2476a 2× Light Bluish Gray

Brick Round 1 x 1...

Part #: 25214 8× Black

Antenna 8H Whip

Part #: 2569 2× Black

Technic Pin with ...

Part #: 2780 175× Black

Tile 1 x 2 with G...

Part #: 3069b 2× Dark Turquoise

Tile 1 x 2 with G...

Part #: 3069b 2× Black

Technic Beam 1 x ...

Part #: 32009 8× Black

Technic Axle and ...

Part #: 32013 5× White

Technic Axle and ...

Part #: 32014 1× Black

Technic Axle and ...

Part #: 32015 2× White

Technic Axle and ...

Part #: 32034 1× White

Technic Pin Long ...

Part #: 32054 12× Light Bluish Gray

Technic Pin Long ...

Part #: 32054 6× Red

Technic Axle 2 No...

Part #: 32062 10× Red

Technic Axle 5

Part #: 32073 4× Yellow

Technic Bush 1/2 ...

Part #: 32123b 10× Light Bluish Gray

Technic Beam 2 x ...

Part #: 32140 6× Dark Turquoise

Technic Beam 2 x ...

Part #: 32140 6× Black

Technic Axle and ...

Part #: 32184 6× Light Bluish Gray

Technic Axle and ...

Part #: 32184 2× Black

Technic Axle and ...

Part #: 32192 6× White

Technic Gear 12 T...

Part #: 32270 4× Black

Technic Beam 1 x ...

Part #: 32271 4× Black

Technic Beam 1 x ...

Part #: 32278 5× Black

Technic Axle and ...

Part #: 32291 8× Black

Technic Beam 1 x ...

Part #: 32316 7× Black

Technic Beam 1 x ...

Part #: 32316 9× Dark Turquoise

Technic Beam 1 x ...

Part #: 32348 9× Black

Technic Ball Joint

Part #: 32474 2× Dark Turquoise

Technic Gear 36 T...

Part #: 32498 1× Black

Technic Beam 1 x ...

Part #: 32523 8× Dark Turquoise

Technic Beam 1 x ...

Part #: 32523 2× Red

Technic Beam 1 x ...

Part #: 32523 2× Green

Technic Beam 1 x ...

Part #: 32523 2× Yellow

Technic Beam 1 x ...

Part #: 32523 2× White

Technic Beam 1 x ...

Part #: 32523 2× Blue

Technic Beam 1 x ...

Part #: 32523 10× Black

Technic Beam 1 x ...

Part #: 32524 11× Black

Technic Beam 1 x ...

Part #: 32524 1× White

Technic Beam 1 x ...

Part #: 32525 7× Black

Technic Beam 3 x ...

Part #: 32526 6× Dark Turquoise

Technic Beam 3 x ...

Part #: 32526 12× Black

Technic Pin Long ...

Part #: 32556 6× Tan

Technic Pin Conne...

Part #: 32557 4× Black

Technic Gear 24 T...

Part #: 3648b 2× Dark Bluish Gray

Technic Pin witho...

Part #: 3673 18× Light Bluish Gray

Technic Axle 4

Part #: 3705 4× Black

Technic Axle 6

Part #: 3706 2× Red

Technic Axle 8

Part #: 3707 2× Black

Technic Axle 12

Part #: 3708 2× Black

Technic Bush

Part #: 3713 10× Light Bluish Gray

Sensor, Color, SPIKE

Part #: 37308 1× White

Sensor, Distance,...

Part #: 37316 1× White

Technic Axle Pin ...

Part #: 3749 6× Tan

Wheel 57 x 14 wit...

Part #: 39367pat0002 6× Black

Technic Base Fram...

Part #: 39369 1× Dark Turquoise

Dish 8 x 8 Invert...

Part #: 3961 1× Dark Turquoise

Technic Beam Fram...

Part #: 39790 2× Black

Technic Connector...

Part #: 39793 9× Dark Turquoise

Technic Beam Fram...

Part #: 39794 2× Black

Cable, USB, SPIKE...

Part #: 39881 1× White

Technic Beam 1 x ...

Part #: 40490 14× Dark Turquoise

Technic Beam 1 x ...

Part #: 41239 5× White

Ball, Hard Plasti...

Part #: 41250 1× Red

Tile 1 x 8 with G...

Part #: 4162 2× Black

Technic Axle and ...

Part #: 41678 4× Black

Technic Axle and ...

Part #: 42003 4× Dark Turquoise

Technic Axle Conn...

Part #: 42135 3× Black

Technic Pin 1/2 w...

Part #: 4274 10× Light Bluish Gray

Technic Axle Pin ...

Part #: 43093 60× Blue

Technic Axle 7

Part #: 44294 4× Light Bluish Gray

Dish 6 x 6 Invert...

Part #: 44375b 1× White

Technic Pin Conne...

Part #: 44874 4× Light Bluish Gray

Technic Axle 3

Part #: 4519 9× Light Bluish Gray

Technic Axle Conn...

Part #: 45590 4× Black

Projectile, Arrow...

Part #: 46537 2× Light Bluish Gray

Technic Panel Car...

Part #: 46882 2× White

Technic Pin Conne...

Part #: 49130 4× Light Bluish Gray

Wire Clip with Ax...

Part #: 49283 8× Dark Turquoise

Launcher, Brick S...

Part #: 49743c01 2× Dark Bluish Gray

Motor, Medium Ser...

Part #: 54696 4× Light Bluish Gray

Projectile, Large...

Part #: 54821 1× Red

Technic Axle 8 wi...

Part #: 55013 4× Dark Bluish Gray

Wheel 18 x 14 wit...

Part #: 55889 4× Black

Wheel 18 x 8 with...

Part #: 56903 4× White

Technic Axle 5.5 ...

Part #: 59426 2× Dark Bluish Gray

Technic Axle Conn...

Part #: 59443 8× White

Technic Beam 1 x ...

Part #: 60483 3× White

Technic Beam 1 x ...

Part #: 60483 2× Black

Technic Beam 3 x ...

Part #: 60484 6× Dark Turquoise

Technic Axle 9

Part #: 60485 2× Yellow

Tyre Offset Tread...

Part #: 61254 4× Black

Technic Pin Conne...

Part #: 62462 8× Black

Technic Panel Cur...

Part #: 62531 3× White

Technic Axle and ...

Part #: 63869 7× Light Bluish Gray

Technic Beam Fram...

Part #: 64179 5× Black

Technic Panel Fai...

Part #: 64391 2× White

Technic Panel Fai...

Part #: 64393 3× White

Technic Panel Fai...

Part #: 64681 3× White

Technic Panel Fai...

Part #: 64683 2× White

Technic Panel 5 x...

Part #: 64782 4× White

Technic Pin Doubl...

Part #: 65098 4× Light Bluish Gray

Technic Axle and ...

Part #: 6536 8× Dark Turquoise

Differential Gear...

Part #: 65413 1× Red

Differential Gear...

Part #: 65414 1× Light Bluish Gray

Technic Pin Conne...

Part #: 65487 18× White

Technic Pin Conne...

Part #: 65489 12× Light Bluish Gray

Technic Pin Long ...

Part #: 6558 82× Blue

Technic Gear 12 T...

Part #: 6589 6× Tan

Tile 1 x 6 with G...

Part #: 6636 2× Black

Technic Pin with ...

Part #: 66906 4× Black

Battery Pack, Rec...

Part #: 67704 1× Dark Turquoise

Hub, Programmable...

Part #: 67718 1× Dark Turquoise

Sticker Sheet for...

Part #: 73229 1× [No Color/Any Color]

Hose Rigid 3mm D....

Part #: 75c08 2× Light Bluish Gray

Rubber Belt Small...

Part #: 85543 2× White

Tile 2 x 4 with G...

Part #: 87079 1× Dark Turquoise

Technic Panel Fai...

Part #: 87080 2× White

Technic Axle 4 wi...

Part #: 87083 6× Dark Bluish Gray

Technic Panel Fai...

Part #: 87086 2× White

Technic Turntable...

Part #: 88738 1× Black

Large Figure Weap...

Part #: 98585 6× Black

Technic Axle and ...

Part #: 98989 2× Light Bluish Gray

Technic Axle 4 wi...

Part #: 99008 2× Tan

Technic Turntable...

Part #: 99009 2× Light Bluish Gray

Technic Turntable...

Part #: 99010 2× Black

The set includes a large number of Technic pins and beams, making it a valuable source for builders looking to expand their Technic collection. The dark turquoise elements are also relatively uncommon and desirable for MOCs.

🛒 Where to Buy

eBay

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$359.99

💎 Notable Parts

Black Technic Pin with Friction Ridges Lengthwise and Center Slots (175x) $8.75

Blue Technic Pin Long with Friction Ridges Lengthwise, 2 Center Slots (82x) $4.10

Dark Turquoise Technic Beam 1 x 9 Thick (14x) $2.80

Dark Turquoise Technic Beam 1 x 5 Thick (9x) $1.80

Black Technic Beam 3 x 5 L-Shape Thick (12x) $2.40

Est. BrickLink Part Value

$19.85

💡 MOC Potential

🤖 Custom robot designs with unique functions

🚗 Programmable vehicles with advanced control systems

🌳 Automated plant watering system

📰 Set News

Community Insights

Real opinions from Reddit and YouTube

What Reddit Says

No Reddit discussions found for this set.

What YouTubers Say

1 video found

BlockTalk AI

LEGO YouTubers give the Robot Inventor (51515) a positive reception, with Builderdude35 suggesting it might be the best Mindstorms set yet. While tutorials and unboxing videos make up the other half of the content, the overall sentiment is positive, with the set scoring 3.7/5.

I Designed an Official Mindstorms Model, Neptunian

Unbrickme • 148.0K views Review

What the Community Says

1 YouTube reviews

BlockTalk AI Summary

Unbrickme provides a hands-on review of the LEGO 51515 Robot Inventor set, showing the unboxing and a speed build of the Gelo robot. The video demonstrates the robot's functions and offers overall impressions of the set.

Reddit Reviews

No Reddit reviews found

YouTube Reviews

1 video

I Designed an Official Mindstorms Model, Neptunian

Unbrickme

148.0K views Review

Community Content: These reviews are from Reddit and YouTube users sharing their personal experiences. Opinions may vary.

🤖 Programming Resources

⚡ Quick Start: Build Your First Robot

Charge the Hub: Connect via USB-C for 2 hours (LED shows battery status)
Download App: Get "LEGO MINDSTORMS Robot Inventor" app (iOS/Android/Windows/Mac)
Connect via Bluetooth: Open app → Select hub → Pair device
Build First Model: Follow in-app tutorial (30-60 minutes)
Run Your First Program: Use drag-and-drop blocks to make it move!

💡 First-time programmer? Start with the official app tutorials. You'll go from zero to driving robot in under 1 hour—no coding experience needed!

🚀

Getting Started

Complete beginner's guide to MINDSTORMS programming. Learn visual blocks, transition to Python, and build 5 master robots.

Browse All Guides →

🐍

Python Programming

Transition to text-based Python coding. Learn functions, variables, sensor logic, and motor control. Includes 20+ code examples.

Python Examples →

📚

Tutorials & Projects

Browse 100+ community projects: line-following robots, sumo bots, maze solvers, and more. Step-by-step instructions with code.

MINDSTORMS Hub →

🤖

Ask BlockTalk AI

Get instant answers to programming questions! "How do I make my robot follow a line?" "What's the difference between motors?" "Generate code for a maze solver."

Chat with BlockTalk →

💻 Code Example: Drive Forward 1 Meter

# Import motor and distance functions
from spike import MotorPair

# Initialize motor pair (ports B and F)
motors = MotorPair('B', 'F')

# Drive forward 1 meter (100 cm) at 50% speed
motors.move(100, 'cm', speed=50)

print("Reached destination!")

This Python code makes your robot drive forward exactly 1 meter. Adjust the distance, speed, and motor ports for your robot design. View 20+ more examples →