cliphook.scad

   1
   2 tau = 6.283;
   3 function rads2degs(rads) = rads * 360/tau;
   4
   5 function ClipHook_r2(w,g,l,ye,k) = w/2 + g + w/2;
   6 function ClipHook_r3(w,g,l,ye,k) = k * ClipHook_r2(w,g,l,ye,k);
   7 function ClipHook_yce(w,g,l,ye,k) = g/2 + w + g + w/2 - ClipHook_r3(w,g,l,ye,k);
   8 function ClipHook_xe(w,g,l,ye,k) =
   9         sqrt(pow( ClipHook_r3(w,g,l,ye,k),      2) -
  10              pow( ClipHook_yce(w,g,l,ye,k) + ye, 2));
  11
  12 module ClipHook(w=1.2, g=0.2, l=0.0, ye=0, k=3.0, h=3.5) {
  13   r2 =  ClipHook_r2(w,g,l,ye,k);
  14   r3 =  ClipHook_r3(w,g,l,ye,k);
  15   yce = ClipHook_yce(w,g,l,ye,k);
  16   xe =  ClipHook_xe(w,g,l,ye,k);
  17
  18   xc = -l/2;
  19   yc = g/w + w/2;
  20
  21   echo("ClipHook(w g l ye k h) ", w, g, l, ye, k, h);
  22   echo("ClipHook r2 r3 yce xe =", r2, r3, yce, xe);
  23
  24   $fn = 20;
  25
  26   module jcirc(x,y) { translate([x,y,0]) circle(r=w/2); }
  27   module jarc(cx,cy,r,a1=0,a2=tau) {
  28     astep = (a2-a1)/6;
  29     size = 5*(r+w/2);
  30     translate([cx,cy,0]) {
  31       intersection() {
  32         difference() {
  33                 circle(r=r+w/2);
  34                 translate([0,0,-1])
  35                         circle(r=r-w/2, h=h+2);
  36         }
  37         scale(size,size) {
  38           for (ai=[0:4]) {
  39             echo(" jarc ", a1,a2, astep, ai, rads2degs(a1 + astep*ai) );
  40             rotate(rads2degs(a1 + astep*ai)) {
  41               polygon([ [0,0], [1,0],
  42                         [cos(rads2degs(astep*2)),sin(rads2degs(astep*2))] ]);
  43             }
  44           }
  45         }
  46       }
  47     }
  48   }
  49
  50   linear_extrude(height=h) {
  51     jcirc(-xc, -yc);
  52     jarc(xc, yc, r2, tau*0.25, tau*0.75);
  53   }
  54 }
  55
  56 ClipHook(l=3);