max_x = 18.95;
max_y = 10.9;
max_z = 3.6;

btm_x = 12.3;
btm_z = 1.6;

rbt_x = 1;
rbt_h = 1.75;

mid_x = 7;
mid_y = 7.2;

grp_x = 4.5;
grp_y = 11.75;
grp_z = 1.5;

tri_y = 2.56;
tri_z = 1;
tri_d = 5;
tri_a = 30;

union() {
    // main part
    difference() {
        // overall shape
        cube([max_x, max_y, max_z]);
        
        // bottom clearance
        translate([(max_x-btm_x)/2,-1,-1])
        cube([btm_x,max_y+2,btm_z+1]);
        
        // rabbets
        translate([-1,-1,rbt_h]) 
        cube([rbt_x+1,max_y+2,max_z-rbt_h+1]);
        translate([max_x-rbt_x,-1,rbt_h])
        cube([rbt_x+1,max_y+2,max_z-rbt_h+1]);
        
        translate([(max_x-mid_x)/2,-1,-1])
        cube([mid_x,mid_y+1,max_z+2]);
    }
    
    // grip
    translate([
        (max_x-grp_x)/2,
        (-grp_y+mid_y),
        btm_z
    ])
    union() {
        // main grip section
        difference() {
            cube([grp_x, grp_y+1, grp_z]);
            
            translate([0,0,grp_z/2])
            rotate([0,0,45])
            cube([1,5,grp_z+1], center = true);
            
            translate([grp_x,0,grp_z/2])
            rotate([0,0,45])
            cube([5,1,grp_z+1], center = true);
        }
        
        // triangular catch
        translate([0,tri_d,-tri_z])
        difference() {
            cube([grp_x,tri_y,tri_z]);
        
            translate([-1,tri_y,tri_z])
            rotate([tri_a-180,0,0])
            cube([grp_x+2,tri_y,tri_z]);
        }
    }
}