/* spin thing that erin likes */
$fn = 50;
-layer_height = 0.15;
+layer_height = 0.35;
weight = "penny";
// weight = "608zz";
bearing = "608zz";
weight_lip_overhang = 0.3;
bearing_lip_overhang = weight_lip_overhang;
-// TODO: switch wall_thickness -> wall
-wall_thickness = 3;
wall = 3;
penny_thickness = 1.52;
penny_radius = 19.05 / 2;
r2 = bearing_inner_radius,
h = cap_height - 1); } } }
-module ring(outer_radius, inner_radius) {
+module donut(height, footprint_radius) {
+ bread_radius = height / 2;
+ rotate_extrude() {
+ translate([footprint_radius, 0]) {
+ circle(bread_radius); } } }
+
+module donut_hole(height, footprint_radius) {
difference() {
- circle(outer_radius);
- circle(inner_radius); } }
+ cylinder(r = footprint_radius, h = height, center = true);
+ donut(height, footprint_radius); } }
+
+module jelly_filled(height, footprint_radius) {
+ cylinder(r = footprint_radius, h = height, center = true);
+ donut(height, footprint_radius); }
module fillet(r) {
offset(r = -r) { offset(delta = r) { children(); } } }
-module spin_footprint(weight_radius,
- bearing_radius,
- round_extra,
- wall,
- arms) {
- thinner_radius = (bearing_radius < weight_radius)?
- bearing_radius : weight_radius;
- fillet(thinner_radius) {
- for(arm = [0 : arms - 1]) {
- hull() {
- circle(bearing_radius + round_extra);
- rotate( (arm / arms) * 360 ) {
- translate([bearing_radius + wall + weight_radius, 0]) {
- circle(weight_radius + round_extra); } } } } } }
-
module mirrored(axis) {
children();
mirror(axis) children(); }
-module spin(weight_radius,
- weight_thickness,
- bearing_radius,
- bearing_thickness,
- weight_lip_overhang = 0.3,
- bearing_lip_overhang = 0.3,
- wall = 3,
- arms = 3) {
- layer_height = 0.15;
+module spin_slice(weight_radius,
+ bearing_radius,
+ round_extra,
+ wall,
+ arms) {
+ joiner_radius = (bearing_radius + weight_radius) / 2;
+
+ bearing_xy = [0, 0];
+ // a = side along x axis
+ a = bearing_radius + weight_radius + wall;
+ // b = side from center to joiner
+ b = bearing_radius + joiner_radius + round_extra;
+ // c = side between joiner and arm center
+ c = joiner_radius + weight_radius + round_extra;
+
+ weight_xy = [a, 0];
+
+ cos_C = (pow(a, 2) + pow(b, 2) - pow(c, 2)) / (2 * a * b);
+ sin_C = sqrt(1 - pow(cos_C, 2));
+
+ joiner_xy = [cos_C, sin_C] * b;
+
+ for(arm = [0 : arms - 1]) {
+ rotate(arm * (360 / arms)) {
+ difference() {
+ union() {
+ translate(bearing_xy) {
+ circle(bearing_radius + round_extra); }
+ translate(weight_xy) {
+ circle(weight_radius + round_extra); }
+ mirrored([0, 1]) {
+ polygon([bearing_xy, weight_xy, joiner_xy]); } }
+ mirrored([0, 1]) {
+ translate(joiner_xy) {
+ circle(joiner_radius); } } } } } }
+
+module spin_slices(weight_radius,
+ weight_thickness,
+ bearing_radius,
+ bearing_thickness,
+ weight_lip_overhang = 0.3,
+ bearing_lip_overhang = 0.3,
+ wall = 3,
+ arms = 3,
+ layer_height = 0.15) {
thicker_thickness = (bearing_thickness > weight_thickness) ?
bearing_thickness : weight_thickness;
calculated_height = thicker_thickness + 2 * wall;
actual_height = layers * layer_height;
round_radius = actual_height / 2;
- mirrored([0, 0, 1]) {
- for(layer = [0 : (layers / 2) - 1]) {
- translate([0, 0, layer * layer_height - actual_height / 2]) {
- linear_extrude(height = layer_height) {
- adjacent = round_radius - (layer * layer_height);
- angle = acos(adjacent / round_radius);
- round_extra = adjacent * tan(angle);
- spin_footprint(weight_radius,
- bearing_radius,
- round_extra,
- wall,
- arms); } } } } }
+ /* rounding the outside edge of the spinner with a semi-circle leads
+ to a shape that an overhang on the second layer several times the
+ thickness of a printed extrusion width.
+
+ rather than using a full semi-circle, this code aims to use just the
+ portion in the middle, where the overhang is less severe */
+ old_start = 0;
+ old_end = (layers / 2) - 1;
+
+ /* add one to have some thickness all around weight holes
+ for first layer */
+ new_start = old_end / 8 + 1;
+ new_end = old_end;
+
+ old_range = old_end - old_start;
+ new_range = new_end - new_start;
+
+ factor = new_range / old_range;
+
+ /* initial adjacent is adjusted to (new start - 1) to allow some
+ thickness all around weight holes on first layer */
+ initial_adjacent = round_radius - ((new_start - 1) * layer_height);
+ initial_angle = acos(initial_adjacent / round_radius);
+ initial_round_extra = initial_adjacent * tan(initial_angle);
+
+ difference() {
+ mirrored([0, 0, 1]) {
+ for(layer = [0 : (layers / 2) - 1]) {
+ translate([0, 0, layer * layer_height - actual_height / 2]) {
+ linear_extrude(height = layer_height) {
+ new_layer = (layer - old_start) * factor + new_start;
+ adjacent = round_radius - (new_layer * layer_height);
+ angle = acos(adjacent / round_radius);
+ round_extra = adjacent * tan(angle) - initial_round_extra;
+ spin_slice(weight_radius,
+ bearing_radius,
+ round_extra,
+ wall,
+ arms); } } } }
+ cylinder(h = actual_height + 0.1,
+ r = bearing_radius - bearing_lip_overhang,
+ center = true);
+ cylinder(h = bearing_thickness + 0.1,
+ r = bearing_radius + 0.1,
+ center = true);
+ for(arm = [0 : arms - 1]) {
+ rotate(arm * (360 / arms)) {
+ translate([bearing_radius + wall + weight_radius, 0]) {
+ cylinder(h = actual_height + 0.1,
+ r = weight_radius - weight_lip_overhang,
+ center = true);
+ cylinder(h = weight_thickness + 0.1,
+ r = weight_radius + 0.1,
+ center = true); } } } } }
/*
This file is part of 3d-printables.
projects / ozzloy@gmail.com / 3d-printables / blobdiff