sirens/designs/openscad/tests/impeller.scad

// Impeller Parameters
diameter = 100;       // Overall base diameter
hub_diameter = 30;    // Diameter of the central hub
hub_height = 10;      // Height of the central hub
base_thickness = 3;   // Thickness of the base
shaft_diameter = 10;  // Diameter of the central shaft hole
blade_count = 6;      // Number of blades
blade_length = 35;    // Length of blades from hub
blade_thickness = 3;  // Thickness of blades
blade_height_at_hub = 5;     // Blade height at the hub
blade_height_at_diameter = 20;  // Blade height at full diameter

module impeller_base() {
    // Base with hub
    difference() {
        union() {
            // Solid base disk
            cylinder(h = base_thickness, d = diameter, center = false);
            
            // Central hub
            translate([0, 0, base_thickness]) 
                cylinder(h = hub_height, d = hub_diameter, center = false);
        }
        
        // Countersink for shaft entry
        translate([0, 0, -0.1]) 
            cylinder(h = 1, d1 = shaft_diameter, d2 = shaft_diameter + 2, center = false);
        
        // Through hole for shaft
        translate([0, 0, base_thickness - 0.1]) 
            cylinder(h = hub_height + 0.2, d = shaft_diameter, center = false);
    }
}

module impeller_blade() {
    // Blade with base always touching the impeller base
    polyhedron(
        points = [
            // Bottom points at hub
            [hub_diameter/2, -blade_thickness/2, base_thickness],
            [hub_diameter/2, blade_thickness/2, base_thickness],
            
            // Bottom points at full diameter
            [diameter/2, -blade_thickness/2, base_thickness],
            [diameter/2, blade_thickness/2, base_thickness],
            
            // Top points at hub
            [hub_diameter/2, -blade_thickness/2, base_thickness + blade_height_at_hub],
            [hub_diameter/2, blade_thickness/2, base_thickness + blade_height_at_hub],
            
            // Top points at full diameter
            [diameter/2, -blade_thickness/2, base_thickness + blade_height_at_diameter],
            [diameter/2, blade_thickness/2, base_thickness + blade_height_at_diameter]
        ],
        faces = [
            [0, 2, 3, 1],    // Bottom face
            [0, 1, 5, 4],    // Inner side bottom
            [2, 6, 7, 3],    // Outer side bottom
            [4, 5, 7, 6],    // Top face
            [0, 4, 6, 2],    // Side face 1
            [1, 3, 7, 5]     // Side face 2
        ]
    );
}

module impeller_blade() {
    polyhedron(
        points = [
            // Bottom points at hub - SHIFTED OUTWARD
            [hub_diameter/2 + base_thickness * tan(30), -blade_thickness/2, base_thickness],
            [hub_diameter/2 + base_thickness * tan(30), blade_thickness/2, base_thickness],
            
            // Bottom points at full diameter - SHIFTED OUTWARD
            [diameter/2 + base_thickness * tan(30), -blade_thickness/2, base_thickness],
            [diameter/2 + base_thickness * tan(30), blade_thickness/2, base_thickness],
            
            // Top points at hub - INCREASED RADIAL ANGLE
            [hub_diameter/2 + blade_height_at_hub * tan(30), -blade_thickness/2, base_thickness + blade_height_at_hub],
            [hub_diameter/2 + blade_height_at_hub * tan(30), blade_thickness/2, base_thickness + blade_height_at_hub],
            
            // Top points at full diameter - INCREASED RADIAL ANGLE
            [diameter/2 + blade_height_at_diameter * tan(30), -blade_thickness/2, base_thickness + blade_height_at_diameter],
            [diameter/2 + blade_height_at_diameter * tan(30), blade_thickness/2, base_thickness + blade_height_at_diameter]
        ],
        faces = [
            [0, 2, 3, 1],    // Bottom face
            [0, 1, 5, 4],    // Inner side bottom
            [2, 6, 7, 3],    // Outer side bottom
            [4, 5, 7, 6],    // Top face
            [0, 4, 6, 2],    // Side face 1
            [1, 3, 7, 5]     // Side face 2
        ]
    );
}


module impeller_blades() {
    // Add blades
    for (i = [0:360/blade_count:359]) {
        rotate([0, 0, i]) {
            impeller_blade();
        }
    }
}

module impeller_column() {
    // Column Parameters
    column_height = blade_height_at_diameter + base_thickness;  // Height matches blade height
    num_ports = blade_count;        // Number of ports matching blade count
    wall_thickness = 5;   // Thickness of the column wall
    outer_diameter = diameter;  // Diameter of the impeller base

    // Calculate port width based on equal arc length
    port_width = (PI * outer_diameter) / (num_ports * 2);
    
    // Calculate inner diameter based on wall thickness
    inner_diameter = outer_diameter - (2 * wall_thickness);
    
    // Rotate by half the port width
    rotate([0, 0, 180/(num_ports * 2)]) 
    difference() {
        union() {
            // Main cylindrical body
            cylinder(h = column_height, d = outer_diameter, $fn = 100);
            
            // Close the bottom with wall_thickness height
            cylinder(h = wall_thickness, d = outer_diameter, $fn = 100);
        }
        
        // Hollow out the center (open on top end)
        translate([0, 0, wall_thickness])
        cylinder(h = column_height + 1, d = inner_diameter, $fn = 100);
        
        // Create evenly spaced rectangular ports
        for (i = [0 : num_ports - 1]) {
            rotate([0, 0, i * (360 / num_ports)])
            translate([outer_diameter/2 - wall_thickness * 2, -port_width/2, 0])
            cube([wall_thickness * 2 + 1, port_width, column_height + 10]);
        }
    }
}



module complete_impeller() {
    // Combine base and blades
    impeller_base();
    impeller_blades();
    //impeller_column();
}

// Render the complete impeller
complete_impeller();