$fn=64;

// --- Parameters ---
base_radius = 50;
base_thickness = 15;

ball_radius = 6.0;
socket_radius = 6.2; // Slightly larger for snap-fit clearance
arm_length = 20;

alligator_hole_diameter = 4.2; // Standard alligator clip friction fit

// --- Print Layout ---
// Lays out all parts flat on the build plate for easy 3D printing

base();

// Generate 4 arms, each with 4 segments and 1 end effector
for(arm=[0:3]) {
    for(seg=[0:3]) {
        translate([base_radius + 20 + seg*22, -33 + arm*22, 0]) 
            arm_segment();
    }
    translate([base_radius + 20 + 4*22, -33 + arm*22, 0])
        end_effector();
}

// --- Modules ---

module base() {
    union() {
        difference() {
            // Main base body (Hexagon)
            cylinder(r=base_radius, h=base_thickness, $fn=6);
            // Center tray for parts/sponge
            translate([0,0,base_thickness - 4]) 
                cylinder(r=base_radius*0.6, h=4.1, $fn=6);
        }
        // Ball mounts for arms
        for(i=[30 : 90 : 300]) {
            rotate([0,0,i]) translate([base_radius*0.75, 0, base_thickness-0.1]) {
                cylinder(r=ball_radius*0.8, h=8.1);
                translate([0,0,8]) sphere(r=ball_radius);
            }
        }
    }
}

module arm_segment() {
    difference() {
        union() {
            // Socket body
            cylinder(r=socket_radius+2.5, h=socket_radius+6);
            // Neck
            translate([0,0,socket_radius+6 - 0.1]) 
                cylinder(r=ball_radius*0.65, h=arm_length+0.2);
            // Top Ball
            translate([0,0,socket_radius+6+arm_length]) 
                sphere(r=ball_radius);
        }
        // Socket internal cavity
        translate([0,0,5]) sphere(r=socket_radius);
        // Bottom chamfer for easy insertion
        translate([0,0,-0.1]) 
            cylinder(r1=socket_radius+0.5, r2=5.2, h=2.1);
        // Slits for snapping (flexibility)
        translate([-(socket_radius+3.5), -1, -0.1]) 
            cube([(socket_radius+3.5)*2, 2, socket_radius+6.2]);
        translate([-1, -(socket_radius+3.5), -0.1]) 
            cube([2, (socket_radius+3.5)*2, socket_radius+6.2]);
    }
}

module end_effector() {
    difference() {
        union() {
            // Socket body
            cylinder(r=socket_radius+2.5, h=socket_radius+6);
            // Top cylinder for clip
            translate([0,0,socket_radius+6 - 0.1]) 
                cylinder(r=socket_radius+2.5, h=10.1);
        }
        // Socket internal cavity
        translate([0,0,5]) sphere(r=socket_radius);
        // Bottom chamfer
        translate([0,0,-0.1]) 
            cylinder(r1=socket_radius+0.5, r2=5.2, h=2.1);
        // Slits for snapping
        translate([-(socket_radius+3.5), -1, -0.1]) 
            cube([(socket_radius+3.5)*2, 2, socket_radius+6.2]);
        translate([-1, -(socket_radius+3.5), -0.1]) 
            cube([2, (socket_radius+3.5)*2, socket_radius+6.2]);
        // Hole for alligator clip
        translate([0,0,socket_radius+6 + 2]) 
            cylinder(r=alligator_hole_diameter/2, h=10);
    }
}