//magnet clip  

// sizes 6h, 10d
// 3h, 20d


mh = 3;  // magnet height
md = 20; // magnet diameter

cl= 0.5; //clearance  
wt = 0.8; // wall thickness

$fn=100;


module body(){
   difference(){
     union(){
        cube([md+cl+wt+wt,mh+cl+wt+wt,md+cl+wt+wt]);
         translate([((md+cl+wt+wt)/2),-3.2,0])
         plug(3.5,8,5,4);  // ring for string
           } 
       translate([(md+wt+wt+cl)/2,cl+wt+mh,wt+cl+md/2])
       rotate([90,0,0])
       plug (wt+cl+(md)/2,md+cl,mh+cl,0);
             }
}

module plug(h,d,t,id){  // distance edge to centre, diam, thick, diam hole
    difference(){
       union(){
          cylinder (h=t,d=d);
          translate([-d/2,0,0])
          cube([d,h,t]);
              }
          translate ([0,0,-t/2])
          cylinder(h=2*t,d=id);
               }
}

body();

translate ([(md+cl)/2,-8,0]) // offset for printing
rotate([0,0,180])
    intersection(){
       translate([0,-(md+cl)/4,0]) // chop off sharp edges
       rotate([0,0,45])
       cube(200);
       plug((md/2)+cl+wt,md+cl,mh,md+cl);
                  }