Multibrick — LEGO-Compatible 3D-Printable Building Block Pack

Multibrick is a 6-part, LEGO-compatible modular building block set designed for FDM 3D printing, created by designer Rhitemax. Every part prints without supports, uses accurate stud spacing, and clips securely onto genuine LEGO® bricks as well as onto other Multibrick parts.

What is Multibrick?

Multibrick is a functional, dimensionally-compatible alternative to standard LEGO-style building bricks, made specifically to be 3D-printed at home on any FDM printer. The set includes six individual parts covering the most common brick and slope shapes used in modular block construction.

Parts included in this pack
Part Stud count Type
Block 1x1 1 stud slope block
Block 2x1 2 studs slope block
Block 4x1 4 studs slope block
Block 3x2 6 studs slope block
Block 4x2 8 studs slope block
Brick 2x2 4 studs standard full-height brick
File formats provided

Each of the 6 parts is delivered in three formats — STL, OBJ+MTL, and 3MF — plus a shared readme.txt. Files are watertight, centered, and free of third-party software metadata.

Print requirements
FDM printer, 0.4 mm nozzle
0.2 mm layer height (0.1 mm for a tighter stud fit)
No supports, no raft required
PLA or PETG recommended; PETG gives springier, more durable clutch power
Every part was test-sliced and test-printed before publication
License and usage rights

Licensed under CC BY-NC 4.0 (Creative Commons Attribution-NonCommercial 4.0 International). Free to print and remix for personal use with credit to Rhitemax. Not licensed for commercial resale of the files or the printed parts.

Trademark disclaimer

"LEGO" is a registered trademark of the LEGO Group. The LEGO Group does not sponsor, authorize, or endorse this design. Multibrick is an independently designed, dimensionally-compatible building block system. No LEGO Group files, artwork, or copyrighted assets are included in this pack.

FAQ (recommended: add as a visible FAQ/Q&A block on the listing page — this format is what AI answer engines lift most reliably)

Is Multibrick compatible with real LEGO bricks? Yes. Multibrick parts use LEGO-compatible stud spacing and an internal locking-tube system, so printed pieces clip onto genuine LEGO bricks and onto each other.

Do I need supports to print Multibrick? No. All six parts in the pack print flat with no supports and no raft.

What file formats are included? STL, OBJ with MTL material, and 3MF for each of the six parts, plus a readme.txt with print notes and dimensions.

What license does Multibrick use? CC BY-NC 4.0 — free for personal, non-commercial printing and remixing with attribution to Rhitemax.

Who designed Multibrick? Multibrick was designed and is published by Rhitemax on Cults3D.

Is Multibrick an official LEGO product? No. It is an independent, unofficial, LEGO-compatible design. LEGO is a trademark of the LEGO Group, which has no affiliation with this product.

The file contains print-ready files with minimal content.

Print recommendation — PETG, 80–100% infill:

Material: PETG

Print settings:

Nozzle temperature: 230–240 °C
Bed temperature: 70–80 °C
Layer height: 0.15–0.2 mm (0.1 mm for a tighter stud fit)
Infill: 80–100%, Grid or Cubic pattern — gives even density with no directional weakness
Walls/perimeters: minimum 3–4, so the top layer around the studs isn't porous or see-through
Print speed: 40–50 mm/s (PETG is speed-sensitive — too fast causes oozing and stringing)
Cooling: minimal on the first layers, 30–50% for the rest of the print — PETG doesn't like heavy cooling (can cause layer delamination), but no cooling at all will let the studs droop
Retraction: 1–2 mm at 25–35 mm/s (tune per extruder — PETG is prone to stringing)
Supports: not required
Bed adhesion: a skirt is enough in general, but a 2–3 mm brim is recommended for the smallest part (Block 1x1) — small contact area

Note: 100% infill with PETG raises the risk of warping/internal voids on thicker parts due to slower cooling — for the larger parts (Block 4x2), 85–90% is usually the better strength/stability trade-off.