// hinge2.cs

pd = 3 //pin diameter
l = 50 // hinge length
w = 15 // hinge width
d = 8 // diameter of pin tube
t = 3 // thickness of blade
nh = 3 // number of fixing holes
dh = 4 // diameter of fixing holes
np = 3 // number of pivots per blade
tol = 1 // tolerance between parts
//ps = 30    // parts seperation for set (1 pin, 2 blades)
bev =2  // corner bevel

///////////////////////////////////

// cylinder for pin 
tu= cylinder(h=l,d1=d,d2=d)
// blade
bl=cube([l,w,t])
// fixing holes
 hl = cylinder(h=3*t,d1=dh,d2=dh)
 spx= l/nh
 spy= (w+(d/2))/2
 for j= spx/2 to l step spx
 hp= translate (hl,[j,spy,-t])
 bl = difference([bl,hp])
 next
// position blade to tube
bl=rotate (bl,[0,-90,0])
xm= (d/2)-t
bl=translate(bl,[-xm,0,0])
bl= union([bl,tu])
// hole for pin
hl= cylinder (h=3*l,d1=pd+tol,d2=pd+tol)
hl= translate(hl,[0,0,-l])
bl=difference ([bl,hl])

// notch blade, ln = length of notch, d = d+tol
// l= (np*2*pl) +(np-1)*tol)  ... l/np= 2*(pl+ tol)-tol
pl= (((l+tol)/np)-tol)/2
os= pl +pl +tol  //offset for notch
not= cylinder (h=pl+tol,d1=d+tol,d2=d+tol)
for j= pl to l step os
np =translate(not,[0,0,j])
print(j)
bl= difference([bl,np])
next
//pin
pin =cylinder (h=l,d1=pd,d2=pd) 
wedge = cylinder (h= pl,d1=pd+tol,d2=pd)
pin = union ([pin,wedge])
pin= rotate(pin,[-90,0,0])
pin= translate(pin,[d*2,0,pd/2.8] )
//flatten bottom of pin  by difference
dif0=cube([1000,1000,1000],center=true)
dif = translate(dif0,[0,0,-500]) 
pin= difference([pin,dif])
// move blade to center and rotate 45deg
bl=translate(bl,[0,-w/2,-l/2])
bl=rotate(bl,[-45,0,0])
// diag height
dh= 0.707*(l+w)  //diagonal height
off= (dh/2)-bev  // offset from bevel to centre
// cut corners by intersect of translated cube
cs=1000
inc=cube([cs,cs,cs],center=true)
cd= cs/2
inc= translate(inc,[0,-cd+off,cd-off])
bl=intersect([bl,inc])
// arrange for print
ps=off+d+5
bl=translate(bl,[0,0,off])
bl2 =translate(bl,[0,ps+(d/2),0])

show_obj([pin,bl,bl2],"printhinge2.obj")