3 include <commitid.scad>
7 // alpha is slope angle, which is half of inner concave angle that
11 // mu is minimum number of cable radii that cable tangent point (line)
12 // with splint ought to be away from edge of split
15 // wall thickness, and base width as fraction of cable size
21 strap_width = 3.0 + 0.5;
25 // for cross-section calculations:
27 // origin O is at intersection of straight line segments forming walls
28 // C is centre of circle (wire x-section) (of radius r or radius 1)
29 // which is tangent to lines
30 // T is said tangent points
31 // B is inner base point, which is extension of line from B by mu*r
37 // blah_r is blah where r=1
38 // d_AB is distance AB
39 // dy_AB is " " " vertical component
46 dy_OB_r = d_OB_r * sina;
48 // *0 and *1 relate to smallest and largest wire
50 // r10 is radius ratio
52 r10 = d_OC_r / dy_OB_r;
54 r0 = rnom / sqrt(r10);
55 r1 = rnom * sqrt(r10);
57 x_B_r = d_OB_r * cosa;
63 wall_x_r = wall_r / tan(90-alpha);
65 top = wall_r * r1 - (d_OC_r - 1) * r0;
66 basew = base_r * rnom;
68 echo("dias", r0*2, r1*2, "ratio",r1/r0);
70 module CrossSectionHalf(plus=0) {
72 polygon([[-0.1, y_T_r * r0],
73 [x_T_r * r0, y_T_r * r0],
74 [x_B_r * r1, y_B_r * r1],
75 [x_B_r * r1 + wall_x_r * rnom + plus, y_B_r * r1],
78 translate([0, -d_OC_r * r0])
79 circle(r = r0, $fn=20);
83 module CrossSection(plus=0) {
86 CrossSectionHalf(plus);
90 module CrossSectionDemo(){ ////toplevel
91 color("black") CrossSection(2);
95 color(rc[0]) translate([0, -d_OC_r * rc[1]]) circle(r = rc[1]);
102 writing_dx = total_len / 3;
103 writing_dy = basew*2;
105 module HalfClamp(){ ////toplevel
107 rotate([90,0,0])rotate([0,90,0]){
108 linear_extrude(height=total_len)
111 for (i=[0 : strap_count]){
112 if (i*2 != strap_count) {
114 total_len * (i + 0.5) / (strap_count + 1)])
117 translate([0,0, strap_width/2])
118 linear_extrude(height=strap_wall_l)
119 CrossSection(strap_wall_h);
125 translate([0, -basew, top])
126 Commitid_BestCount([writing_dx, writing_dy]);
130 module HalfClampPrint(){ ////toplevel
136 //CrossSectionDemo();