cadquery/examples/Ex100_Lego_Brick.py

# This script can create any regular rectangular Lego(TM) Brick
import cadquery as cq

#####
# Inputs
######
lbumps = 1  # number of bumps long
wbumps = 1  # number of bumps wide
thin = True  # True for thin, False for thick

#
# Lego Brick Constants-- these make a lego brick a lego :)
#
pitch = 8.0
clearance = 0.1
bumpDiam = 4.8
bumpHeight = 1.8
if thin:
    height = 3.2
else:
    height = 9.6

t = (pitch - (2 * clearance) - bumpDiam) / 2.0
postDiam = pitch - t  # works out to 6.5
total_length = lbumps * pitch - 2.0 * clearance
total_width = wbumps * pitch - 2.0 * clearance

# make the base
s = cq.Workplane("XY").box(total_length, total_width, height)

# shell inwards not outwards
s = s.faces("<Z").shell(-1.0 * t)

# make the bumps on the top
s = (
    s.faces(">Z")
    .workplane()
    .rarray(pitch, pitch, lbumps, wbumps, True)
    .circle(bumpDiam / 2.0)
    .extrude(bumpHeight)
)

# add posts on the bottom. posts are different diameter depending on geometry
# solid studs for 1 bump, tubes for multiple, none for 1x1
tmp = s.faces("<Z").workplane(invert=True)

if lbumps > 1 and wbumps > 1:
    tmp = (
        tmp.rarray(pitch, pitch, lbumps - 1, wbumps - 1, center=True)
        .circle(postDiam / 2.0)
        .circle(bumpDiam / 2.0)
        .extrude(height - t)
    )
elif lbumps > 1:
    tmp = (
        tmp.rarray(pitch, pitch, lbumps - 1, 1, center=True)
        .circle(t)
        .extrude(height - t)
    )
elif wbumps > 1:
    tmp = (
        tmp.rarray(pitch, pitch, 1, wbumps - 1, center=True)
        .circle(t)
        .extrude(height - t)
    )
else:
    tmp = s

# Render the solid
show_object(tmp)