$fn=64;

// --- Parameters ---
// SAE Sizes: 1/16, 5/64, 3/32, 1/8, 5/32, 3/16, 1/4, 5/16, 3/8
// Converted to mm with ~0.4mm clearance for easy drop-in insertion
hole_diams = [2.0, 2.4, 2.8, 3.6, 4.4, 5.2, 6.8, 8.4, 10.0];
num_keys = len(hole_diams);

spacing = 18;
width = 30;
min_height = 15;
max_height = 45;
bottom_thickness = 5;

total_length = num_keys * spacing;

difference() {
    // Main body with angled top profile
    hull() {
        translate([0, 0, 0]) 
            cube([0.1, width, min_height]);
        translate([total_length - 0.1, 0, 0]) 
            cube([0.1, width, max_height]);
    }

    // Allen key holes and chamfers
    for (i = [0 : num_keys - 1]) {
        x_pos = i * spacing + (spacing / 2);
        
        // Main shaft hole
        translate([x_pos, width / 2, bottom_thickness])
            cylinder(h = max_height, d = hole_diams[i]);
            
        // Calculate approximate top surface height at this hole's X position
        surface_z = min_height + (max_height - min_height) * (x_pos / total_length);
        
        // Chamfer for easier tool insertion
        translate([x_pos, width / 2, surface_z - 2])
            cylinder(h = 5, d1 = hole_diams[i], d2 = hole_diams[i] + 4);
    }
}