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1 | /* GNU AGPLv3 (or later at your option) |
2 | see bottom for more license info */ |
3 | |
4 | /* spin thing that erin likes */ |
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5 | $fn = 500; |
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6 | |
7 | weight = "penny"; |
8 | // weight = "608zz"; |
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9 | bearing = "608zz"; |
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10 | weight_lip_thickness = 1; |
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11 | wall_thickness = 2; |
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12 | penny_thickness = 1.52; |
13 | spinner_height = penny_thickness * 5 + 2; |
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14 | _608zz_radius = 22; |
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15 | _608zz_thickness = 7; |
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16 | penny_radius = 19.05 / 2; |
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17 | weight_radius = (weight == "penny") ? penny_radius : _608zz_radius; |
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18 | weight_thickness = (weight == "penny") ? |
19 | penny_thickness * 5 : _608zz_thickness; |
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20 | bearing_radius = (bearing == "608zz") ? _608zz_radius : 1/0; |
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21 | bearing_thickness = (bearing == "608zz") ? _608zz_thickness : 1/0; |
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22 | arms = 3; |
23 | |
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24 | module ring(outer_radius, inner_radius) { |
25 | difference() { |
26 | circle(outer_radius); |
27 | circle(inner_radius); } } |
28 | |
29 | module spin_2d(weight_radius, |
30 | arms, |
31 | wall_thickness, |
32 | bearing_radius) { |
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33 | bearing_holder_radius = bearing_radius + wall_thickness; |
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34 | weight_holder_radius = weight_radius + wall_thickness; |
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35 | |
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36 | ring(bearing_holder_radius, bearing_radius); |
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37 | |
38 | /* |
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39 | * imagine a triangle with one point at the origin, at the |
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40 | * center of the spinning bearing holder, one point in the middle of |
41 | * the weight holder, and one point at the center of a circle tangent |
42 | * to the first two, called the joiner circle. |
43 | * the radius of the joiner circle is the arithmetic average of the |
44 | * weight holder and bearing holder. |
45 | */ |
46 | joiner_radius = (bearing_holder_radius + weight_holder_radius) / 2; |
47 | /* a: goes between the center of the weight holder and the center of |
48 | the joiner circle. */ |
49 | a = joiner_radius + weight_holder_radius; |
50 | /* b: length of the base, which goes along the x-axis between |
51 | the origin and the center of the weight holder. */ |
52 | b = weight_holder_radius + bearing_holder_radius; |
53 | /* c: goes between origin and joiner circle. */ |
54 | c = bearing_holder_radius + joiner_radius; |
55 | |
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56 | /* A: angle at the origin, between the base and segment from origin |
57 | to center of joiner circle. |
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58 | it is calculated using law of cosines, given the lengths of |
59 | all 3 sides of the triangle. */ |
60 | A = acos((pow(b, 2) + pow(c, 2) - pow(a, 2)) / (2 * b * c)); |
61 | /* find the center of the joiner circle */ |
62 | joiner_x = cos(A) * c; |
63 | joiner_y = sin(A) * c; |
64 | |
65 | /* find the points where the circles meet */ |
66 | bearing_joiner_point = [cos(A) * bearing_holder_radius, |
67 | sin(A) * bearing_holder_radius]; |
68 | bearing_weight_point = [bearing_holder_radius, 0]; |
69 | /* C: angle between x-axis and line-segment between center of weight |
70 | holder and center of joiner. |
71 | it is calculated using law of cosines, given the lengths of |
72 | all 3 sides of the triangle. */ |
73 | C = acos((pow(a, 2) + pow(b, 2) - pow(c, 2)) / (2 * a * b)); |
74 | weight_joiner_point = [b - cos(C) * weight_holder_radius, |
75 | sin(C) * weight_holder_radius]; |
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76 | for(arm = [0 : arms - 1]) { |
77 | rotate(arm * 360.0 / arms) { |
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78 | difference() { |
79 | polygon([bearing_weight_point, |
80 | bearing_joiner_point, |
81 | weight_joiner_point]); |
82 | translate([joiner_x, joiner_y]) { |
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83 | circle(joiner_radius); } |
84 | translate([weight_holder_radius + bearing_holder_radius, 0]) { |
85 | circle(weight_holder_radius); } } |
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86 | mirror(v = [0, 1, 0]) { |
87 | difference() { |
88 | polygon([bearing_weight_point, |
89 | bearing_joiner_point, |
90 | weight_joiner_point]); |
91 | translate([joiner_x, joiner_y]) { |
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92 | circle(joiner_radius); } |
93 | translate([weight_holder_radius + bearing_holder_radius, 0]) { |
94 | circle(weight_holder_radius); } } } |
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95 | translate([weight_holder_radius + bearing_holder_radius, 0]) { |
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96 | ring(weight_holder_radius, weight_radius); } } } } |
97 | |
98 | module spin(weight_radius, |
99 | weight_thickness, |
100 | weight_lip_thickness, |
101 | arms, |
102 | wall_thickness, |
103 | bearing_radius, |
104 | bearing_thickness, |
105 | spinner_height) { |
106 | /* TODO: make window size parameter */ |
107 | /* TODO: rethink how lips are done */ |
108 | /* TODO: right now, weight is assumed to be thicker than bearing*/ |
109 | bearing_lip_thickness = (spinner_height - bearing_thickness) / 2; |
110 | linear_extrude(height = weight_lip_thickness) { |
111 | spin_2d(weight_radius - 1, |
112 | arms, |
113 | wall_thickness + 1, |
114 | bearing_radius - 1); } |
115 | linear_extrude(height = bearing_lip_thickness) { |
116 | ring(bearing_radius, bearing_radius - 1); } |
117 | linear_extrude(height = spinner_height) { |
118 | spin_2d(weight_radius, arms, wall_thickness, bearing_radius); } |
119 | translate([0, 0, spinner_height - bearing_lip_thickness]) { |
120 | linear_extrude(height = bearing_lip_thickness) { |
121 | ring(bearing_radius, bearing_radius - 1); } } |
122 | translate([0, 0, spinner_height - weight_lip_thickness]) { |
123 | linear_extrude(height = weight_lip_thickness) { |
124 | spin_2d(weight_radius - 1, |
125 | arms, |
126 | wall_thickness + 1, |
127 | bearing_radius - 1); } } } |
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128 | |
129 | /* |
130 | This file is part of 3d-printables. |
131 | |
132 | 3d-printables is free software: you can redistribute it and/or modify |
133 | it under the terms of the GNU Affero General Public License as published by |
134 | the Free Software Foundation, either version 3 of the License, or |
135 | (at your option) any later version. |
136 | |
137 | 3d-printables is distributed in the hope that it will be useful, |
138 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
139 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
140 | GNU Affero General Public License for more details. |
141 | |
142 | You should have received a copy of the GNU Affero General Public License |
143 | along with challenge-bot. If not, see <http://www.gnu.org/licenses/>. |
144 | */ |