Ex100_Lego_Brick.py

# This script can create any regular rectangular Lego(TM) Brick
importcadqueryascq

#####
# 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
ifthin:
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)

iflbumps>1andwbumps>1:
tmp= (
tmp.rarray(pitch, pitch, lbumps-1, wbumps-1, center=True)
 .circle(postDiam/2.0)
 .circle(bumpDiam/2.0)
 .extrude(height-t)
 )
eliflbumps>1:
tmp= (
tmp.rarray(pitch, pitch, lbumps-1, 1, center=True)
 .circle(t)
 .extrude(height-t)
 )
elifwbumps>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)