Brick with Inside Bow 1x6x2

I am always short of some bricks when creating LEGO MOCs (My Own Creation), so I am using FreeCAD and my printer to create temporary placeholders when prototyping.

This model is a brick compatible with LEGO's brick no. 15254 - Brick w. Inside Bow 1x6x2.

The model was designed specifically for 3D printing with tolerances in mind.

For printing I recommend to start with attached FreeCAD project file and modify properties according to Printing Guide.

Printing Guide

(how to preserve compatibility with LEGO when printing)

There are several factors influencing compatibility with LEGO or other bricks system. Building capabality is mainly based on:

• friction, and
• spacing.

Friction is maintained by

• studs and tubes diameter,
• inner walls thickness, and
• auxiliary reinforcments.

Spacing is maintained by

• play tolerance offset.

With common 3D printer, we are not able to match required precision to create adequate friction, we can only approximate.

Basic printing parameters

• Material: PLA or ABS, PETG is not suitable because of worse bridging capability (problem mainly for plates).
• Layer Height: 0.15 or 0.2, both is OK.
• Perimeters: 3, print outside perimeters first
• Infill: does not matter
• Supports: enforced supports as painted in attached 3MF, brim is recommended

Model parameters

Relevant for this model. The model does not have tubes or hollow studs, so it is easier to calibrate.

Play tolerance offset of 0,2 mm is a LEGO standard, there should not be a need to change that.

Beware: Parameters can also slightly differ with various materials, even different color from the same brand can influence the result.

What to do when

• Original LEGO brick does not hold on top of the printed brick (studs are too loose) - add to StudDiaMod in increments of 0,05 mm.
• Original LEGO brick cannot be placed on top of the printed brick (studs are too tight)  - substract from StudDiaMod in increments of 0,05 mm.
• The printed brick does not hold on top of original LEGO brick (walls are too loose) - add to WallThickMod in increments of 0,05 mm.
• The printed brick cannot be placed on top of original LEGO brick (walls are too loose) - substract from WallThickMod

Share your printing settings and parameters for your printer. I will update the table. Exported files (3MF, STEP, STL) are with parameters for my MK4.

Changelog

• 2024/02/14 - Corrected studs diameter in FreeCAD project and exported STEP/STL.

Other Bricks

• Brick Roof Tile 4x2 45° inverted
• Parametric Tile with Groove
• Radiator Grille 1x2