$fn = 128;

// Platter diameter
// 95 for 3.5" and 65 for 2.5" platters
pd = 95; 

height = 2.8;
frame_thickn = 2.4;
frame = pd + frame_thickn * 2;

difference(){
    union(){
        rotate([-0,90,0]) 
          cylinder(h=height, d=frame);
        
        scale([1,0.4,1.6]) rotate([45,0,0])
          translate([height/2, 0, 0])
            cube([height, pd, pd], center=true);
    }
    
    // Shorten to half circle
    translate([0, 0, -frame - 2]) 
      cylinder(h=frame, d=frame + 5);
    
    // Open clamp on top
    translate([0, 0, -12.6]) 
      scale([1,0.4,1.6]) rotate([45,0,0])
        translate([1, 0, 0])
          cube([frame_thickn*3, pd, pd], center=true);
    
    // Cut out inner diameter from circle
    translate([-4, 0, 0]) rotate([0,90,0]) 
      cylinder(h=10, d=pd - frame_thickn/2);
    
    // Cutout for platter
    cylinder(h=1.6, d=pd);
}