$fn=128;

// --- PARAMETERS ---
gap = 60;               // Maximum opening of the clamp
depth = 50;             // Throat depth
thickness = 15;         // Thickness of the clamp body
width = 20;             // Width of the clamp arms
screw_r = 8;            // Radius of the screw (16mm diameter)
pitch = 8;              // Thread pitch (coarse for easy 3D printing)
tolerance = 0.6;        // Clearance for moving parts
screw_length = gap + 30; // Total length of the threaded shaft

// --- PRINT LAYOUT ---
// Arrange parts flat on the build plate
translate([0, 0, 0]) clamp_body();
translate([depth + 40, 0, 15]) screw();
translate([depth + 80, 0, 0]) swivel_pad();

// --- MODULES ---

// Generates a smooth, printable hex-based thread profile
module thread_profile(r) {
    offset(r=1.5) circle(r=r-1.5, $fn=6);
}

// Extrudes the profile into a helical thread
module screw_thread(length, r, p) {
    linear_extrude(height=length, twist=-360*length/p, slices=length*2)
        thread_profile(r);
}

// Main C-Clamp Body
module clamp_body() {
    R = 8; // Inner corner radius
    difference() {
        // Main outer shape
        hull() {
            // Back spine
            translate([-width/2, -width/2, 0]) cylinder(r=width/2, h=thickness);
            translate([-width/2, gap + width/2, 0]) cylinder(r=width/2, h=thickness);
            // Top arm (Anvil)
            translate([depth + width/2, -width/2, 0]) cylinder(r=width/2, h=thickness);
            // Bottom arm (Thread boss)
            translate([depth + width/2, gap + width/2, 0]) cylinder(r=width/2, h=thickness);
        }
        
        // Inner cutout
        translate([0, 0, -1])
        hull() {
            translate([R, R, 0]) cylinder(r=R, h=thickness+2);
            translate([depth+width+1, R, 0]) cylinder(r=R, h=thickness+2);
            translate([R, gap-R, 0]) cylinder(r=R, h=thickness+2);
            translate([depth+width+1, gap-R, 0]) cylinder(r=R, h=thickness+2);
        }
        
        // Threaded Hole
        translate([depth + width/2, gap + width/2, -1])
            screw_thread(length=thickness + 2, r=screw_r + tolerance, p=pitch);
            
        // Chamfers for easier screw insertion
        translate([depth + width/2, gap + width/2, -1])
            cylinder(r1=screw_r + 2, r2=screw_r, h=2);
        translate([depth + width/2, gap + width/2, thickness - 1])
            cylinder(r1=screw_r, r2=screw_r + 2, h=2);
    }
}

// Threaded Screw with Knob and Ball Joint
module screw() {
    ball_r = screw_r - 2;
    
    union() {
        // Threaded Shaft
        screw_thread(length=screw_length, r=screw_r, p=pitch);
        
        // Knurled Handle
        translate([0, 0, -15]) {
            difference() {
                cylinder(r=screw_r * 2.5, h=15.1); // 0.1mm overlap for manifoldness
                // Knurling cutouts
                for(i=[0:20:340]) {
                    rotate([0, 0, i])
                    translate([screw_r * 2.5 + 1, 0, 7.5])
                        cylinder(r=2.5, h=17, center=true);
                }
            }
        }
        
        // Swivel Ball Tip
        translate([0, 0, screw_length - 0.1]) {
            cylinder(r=ball_r - 1.5, h=3.2); // Neck
            translate([0, 0, 3.1 + ball_r])
                sphere(r=ball_r);            // Ball
        }
    }
}

// Snap-on Swivel Foot
module swivel_pad() {
    ball_r = screw_r - 2;
    pad_r = 12;
    pad_h = 12;
    
    difference() {
        // Pad body
        cylinder(r=pad_r, h=pad_h);
        
        // Ball socket
        translate([0, 0, pad_h - ball_r + 0.5]) {
            sphere(r=ball_r + 0.4); // Socket cavity with tolerance
            // Neck opening (slightly restricted for snap fit)
            cylinder(r=ball_r - 0.4, h=ball_r + 2);
        }
        
        // Flex slits to allow the ball to snap in
        translate([0, 0, pad_h - ball_r + 1]) {
            cube([pad_r * 2 + 2, 1.5, ball_r * 2], center=true);
            cube([1.5, pad_r * 2 + 2, ball_r * 2], center=true);
        }
    }
}