Brick calculator

The scad file can be used to make other sizes of bricks.

In order for these to work well with store bought bricks it is important to print with as much dimensional accuracy as possible. I have so far had the best results in Cura 3.2.0 with these settings. I have not been printing with a raft but a raft might give you better adhesion for the undersides of the blocks.

Nozzle is 0.4 mm
Layer Height 0.2 mm
Initial Layer Height 0.3 mm
print thin walls on

Outer before Inner walls on
Enable Ironing on , makes a smoother surface and the connectors seem stronger