Set Details
- Set Number
- 870
- Name
- 4.5V Supplementary Set
- Theme
- Technic
- Year
- 1977
- Pieces
- 22
- Complexity
- Starter
- Build Time
- 10-20 minutes
- Ages
- 4+
- Type
- Play-focused
About LEGO 4.5V Supplementary Set
LEGO 4.5V Supplementary Set (set #870) is a small, compact build with 22 pieces from the Technic theme, released in 1977. The Technic line features mechanically complex models with gears, axles, and motors. This is a starter-level build suitable for ages 4+, with an estimated build time of 10-20 minutes. This set dates from the pre-minifigure era, before LEGO introduced its iconic yellow-faced figures in 1978.
Set Highlights
- 22 pieces at starter complexity — a 10-20 minutes build.
- Compatible with all standard LEGO sets — bricks extend naturally into other sets you own.
- Play-focused build with interactive elements designed for 4+ builders.
- Vintage 1977 release — increasingly rare in complete, unplayed condition.
Who Is This Set For?
Gift for Ages 4+
The starter difficulty makes this accessible without being trivial — a well-matched gift for LEGO fans in the 4+ age range.
Weekend Build Project
22 pieces with an estimated 10-20 minutes fits comfortably into a focused afternoon or weekend session.
Expanding a Technic Collection
A solid addition for collectors building out their Technic shelf. Introduces parts and builds that complement other sets from the same line.
Build Tips
Check the piece count on the bag against the parts list before starting — knowing what you have prevents mid-build surprises.
Even in small sets, connection order matters. Follow the steps rather than building sections independently.
Vintage sets may show slight color variation from modern LEGO due to different ABS formulas. This is normal and part of the set's character, not a defect.
Finding Instructions
Instructions for older sets like #870 (1977) may not always be available on LEGO.com. Try searching the set number directly, or upload a photo of the bricks to LegoFinder — the AI can identify vintage sets from their parts.
4.5V Supplementary Set FAQ
Related Reading
More Technic Sets
See all Technic →
Also Released in 1977
All 1977 sets →Similar Build Difficulty
Sets at roughly the same piece count and complexity tier — different theme and year, but a similar build experience.
Need Instructions for 4.5V Supplementary Set?
Upload a photo of your LEGO 4.5V Supplementary Set set and get the building instructions PDF in seconds.
Upload a Photo Now