hinge.py

from build123d import *
from build123d_draft import *
import math

def make_hinge(center, # hinge around this point
               dia, # outer diameter of the hinge round part
               total_height, # 
               pin_dia=None, # diameter of the hinge pin
               vertical_clearance=0.5, # clearance in Z axis
               horizontal_clearance = 0.5, # clearance in X, Y axes
               side_cut=5, # extra material to cut from the side of the hinge
               no_pin=False, # create with out a pin
               inner_flaps = 1 # determines number of total layers: 1 + 2*inner_flaps 
               ):
    
    if pin_dia is None:
        pin_dia = dia / 2
        
    slice_height = (total_height - 2 * inner_flaps * vertical_clearance) / (1 + 2 *inner_flaps)
    
    def rounded_with_pin(topf, height=slice_height):
        with BuildSketch(topf) as sketch:
             Rectangle(dia/2+horizontal_clearance, dia+horizontal_clearance+side_cut, 
                       align=(Align.MAX, Align.CENTER))
        extrude(to_extrude=sketch.sketch, amount=height, mode=Mode.SUBTRACT)
        
        with BuildSketch(topf) as sketch:
            Circle(d=dia)
        return extrude(to_extrude=sketch.sketch, amount=height)
    
    def pin_only(topf, height=vertical_clearance):
        with BuildSketch(topf) as sketch:
             Rectangle(dia+horizontal_clearance*2, dia+horizontal_clearance*2+10)
        extrude(to_extrude=sketch.sketch, amount=height, mode=Mode.SUBTRACT)
        
        with BuildSketch(topf) as sketch:
            Circle(d=pin_dia)
        return extrude(to_extrude=sketch.sketch, amount=height)
    
    def rotating_around_pin(topf, height=slice_height):
        with BuildSketch(topf) as sketch:
             Rectangle(dia/2+horizontal_clearance, dia+horizontal_clearance+side_cut, 
                       align=(Align.MIN, Align.CENTER))
        extrude(to_extrude=sketch.sketch, amount=height, mode=Mode.SUBTRACT)
        
        with BuildSketch(topf) as sketch:
            Circle(d=dia)
        extrude(to_extrude=sketch.sketch, amount=height)
        
        with BuildSketch(topf) as sketch:
            Circle(d=pin_dia+horizontal_clearance)
        extrude(to_extrude=sketch.sketch, amount=height, mode=Mode.SUBTRACT)
        
        with BuildSketch(topf) as sketch:
            Circle(d=pin_dia)
        return extrude(to_extrude=sketch.sketch, amount=height)
    
    # first layer
    r = rounded_with_pin(Plane.XY.shift_origin(center))
    for _ in range(0, inner_flaps):
        # second layer (pin)
        r = pin_only(r.faces().sort_by(Axis.Z)[-1])
        # third layer
        r = rotating_around_pin(r.faces().sort_by(Axis.Z)[-1])
        # fourth layer (same as 2nd)
        r = pin_only(r.faces().sort_by(Axis.Z)[-1])
        # 5th layer (same as 1st)
        r = rounded_with_pin(r.faces().sort_by(Axis.Z)[-1])
   
    if no_pin:
        with BuildSketch() as sketch:
            with Locations(center):
                Circle(d=pin_dia)
        extrude(to_extrude=sketch.sketch, amount=total_height, mode=Mode.SUBTRACT)

w, h, l = 20, 20, 80

with BuildPart() as part:
    with BuildSketch() as sketch:
        Rectangle(l, w)
    extrude(amount=h)
    make_hinge((0, 0), dia=w, total_height=h, inner_flaps=2)

        
show_object(part.part)