3 // Print, for each end:
13 enable_head_cups = false;
15 main_dia = 71.2 + 0.50 - 2.26;
17 top_thick_by_oring = 3.0;
24 rivet_posn = 6.0 + 0.30;
26 rivet_width = 4.15 + 1.0;
27 rivet_tall = 5.51 + 1.49;
29 over_rivet_wall = 1.0;
31 inside_rivet_gap = 1.5;
35 bayo_interf_width = 2.0;
36 bayo_interf_slope = 0.5;
41 oring_upper_embed_angle = 80;
42 oring_compress = 0.1; // proportion
43 oring_compress_more = 0.2;
56 bayo_slice_size = coarse ? 5 : 1;
58 brace_hole_width = 1.0;
59 brace_above_below = 1.2;
60 brace_end_shorter = 0.3;
68 strap_loop_inside = 10;
69 strap_loop_strlen = 10;
70 strap_loop_elevation = 45;
72 sm_inner_circum = 218 - 1.90 - 1.00 - 0.50;
76 sm_bolt_dia = 3.5 + 0.1;
78 sm_bolt_head_dia = 6.94 + 1.0;
79 sm_bolt_head_thick = 2.14;
80 sm_bolt_nut_width = 5.89 + 0.25;
81 sm_bolt_nut_thick = 3.68;
82 sm_bolt_tighten_allow = 2.0;
84 sm_bolt_y_clear = 0.75;
90 wm_screw_dia = 4.5; // XXX
91 wm_screwdriver_dia = 6.0; // XXX
92 wm_screw_around = 4.0; // XXX
94 wm_screw_head = 7.5; // XXX
97 wmb_screw_head_dia = 10; // XXX
98 wmb_screw_around_x = 4; // XXX
99 wmb_screw_around_z = 6; // XXX
100 wmb_screw_depth_min = 10;
101 web_screw_len = 15 + 1; // XXX
102 wmb_nut_across = 8; // XXX
103 wmb_nut_around_min = 2; // XXX
104 wmb_nut_behind_min = 5;
105 wmb_nut_th = 4; // XXX
106 wmb_mount_wall = 4.5;
107 wmb_mount_gap_xy = 0.5;
108 wmb_mount_y_width = 10;
112 catch_stalk_len = 50;
116 catch_pin_slop = 0.25; // each side, and above
117 catch_pin_slop_x_extra = 0.0; // only on one side
118 catch_stalk_above_gap = 1.5;
119 catch_stalk_eff_bend_rad = catch_stalk_len * 0.75;
121 catch_strap_width = 12;
122 catch_stalk_base_width = 15;
125 catch_knob_above_gap = 5;
126 catch_knob_height = 3.0;
128 catch_stalk_below_gap = 1.0;
129 catch_stalk_beside_gap = 2.0;
135 bayo_entry_x = bayo_entry;
136 bayo_entry_z = bayo_entry;
137 bayo_inramp_x = bayo_inramp;
138 bayo_inramp_z = bayo_inramp;
140 oring_mid_dia = oring_bore + oring_thick;
141 oring_outer_dia = oring_mid_dia + oring_thick;
143 oring_oblate = (1 - oring_compress);
145 oring_y_rad = oring_thick/2 * oring_oblate;
146 oring_x_rad = oring_thick/2 / oring_oblate;
148 by_oring_z = oring_y_rad * (1 + cos(oring_upper_embed_angle));
150 side_height = rivet_posn + bayo_behind + rivet_thick/2;
151 side_thick = rivet_tall + over_rivet_wall;
153 top_z = top_thick_by_oring + oring_y_rad + by_oring_z;
155 middle_bot_z = top_z - top_thick_middle;
157 bayo_top_z = bayo_behind + bayo_gap;
159 bayo_nom_rad = main_dia/2 + side_thick;
160 bayo_real_rad = main_dia/2 + rivet_tall;
162 rivet_entry_width = rivet_width + side_rivet_gap;
164 jig_mark_rad = jig_mark + main_dia/2 + jig_thick;
166 handling_dia = oring_bore + oring_thick*2 + min_wall*2;
169 sm_inner_rad = (sm_inner_circum + sm_bolt_tighten_allow/2) / TAU;
170 sm_outer_rad = sm_inner_rad + sm_main_thick;
172 wm_main_width = sm_main_width;
173 wm_y_min = sqrt( pow(sm_inner_rad, 2) -
174 pow(sm_inner_rad - (wm_thick - sm_main_thick), 2) );
175 wm_y_screw = wm_y_min + wm_screw_around + wm_screw_dia/2;
176 wm_y_max = wm_y_screw + wm_screw_dia/2 + wm_screw_around;
177 wm_y_slotc_screw = wm_y_screw + wm_screw_slot/2;
178 wm_y_slot1_screw = wm_y_screw + wm_screw_slot;
179 wm_y_slot1_max = wm_y_max + wm_screw_slot;
180 wm_z_slot0_screw = wm_main_width + wm_screwdriver_dia/2;
181 wm_z_slotc_screw = wm_z_slot0_screw + wm_screw_slot/2;
182 wm_z_slot1_screw = wm_z_slot0_screw + wm_screw_slot;
183 wm_z_max = wm_z_slot1_screw + wm_screw_around;
185 wmb_mount_cut_rad = sm_outer_rad + wmb_ring_gap;
186 wmb_nut_rad = wmb_nut_across / cos(30) * 0.5;
187 wmb_x_screw_plus_around_r = max(
188 wmb_screw_around_x + wmb_screw_dia/2,
189 wmb_nut_around_min + wmb_nut_across/2
191 wmb_x_screw = -sm_outer_rad + wmb_x_screw_plus_around_r;
192 wmb_x_outer = -sm_outer_rad + wmb_x_screw_plus_around_r * 2;
193 function wmb_screw_thing_y_min(dia) = sqrt(
194 pow(wmb_mount_cut_rad, 2) -
195 pow(wmb_x_screw + dia/2, 2)
197 wmb_y_screw_end = wmb_screw_thing_y_min(wmb_screw_dia);
198 wmb_y_nut_min = wmb_screw_thing_y_min(wmb_nut_across + wmb_nut_around_min*2);
199 wmb_y_mount_max = max(
200 wmb_y_nut_min + wmb_nut_th + wmb_nut_behind_min,
201 wmb_y_screw_end + wmb_screw_depth_min
204 wmb_screw_around_z + wmb_screw_dia/2,
205 wmb_nut_around_min + wmb_nut_rad
207 wmb_z_max = wmb_z_screw * 2;
208 wmbb_y_max = wmb_y_mount_max + wmb_mount_gap_xy + wmb_mount_wall;
209 wmbb_x_outer = wmb_x_outer + (wmb_mount_gap_xy + wmb_mount_wall);
210 wmbb_z_min = -20; // XXX
212 smc_pos = [ 0, sm_inner_rad, 0 ];
214 smc_bolt_nut_dia = sm_bolt_nut_width / cos(30);
215 smc_bolt_nut_eff_thick = sm_bolt_nut_thick + sm_bolt_tighten_allow;
217 smc_bolt_y = sm_bolt_dia/2 + sm_bolt_y_clear;
218 smc_max_y = smc_bolt_y + sm_bolt_y_over
219 + max(sm_bolt_head_dia/2, smc_bolt_nut_dia/2);
220 smc_cnr_c_x = sm_bolt_shaft/2 - sm_closure_cnr
221 + sm_bolt_head_thick/2 + smc_bolt_nut_eff_thick/2;
223 catch_cr = catch_knob_dia/2 + catch_stalk_beside_gap;
224 catch_strap_thick = sm_main_thick;
226 echo("R ", sm_inner_rad, bayo_real_rad, bayo_nom_rad);
228 $fs= coarse ? 2.5 : 0.5;
231 include <poster-tube-lid-parametric.scad>
233 // bayonet definition
235 bayo_a = [ bayo_entry_x, 0 ];
236 bayo_p = [ 0, bayo_entry_z ];
237 bayo_n = [ 0, bayo_behind-bayo_inramp_z ];
238 bayo_m = [ bayo_inramp_x, bayo_behind ];
239 bayo_l = bayo_m + bayo_interf * [ 1/bayo_interf_slope, 1 ];
240 bayo_k = bayo_l + [ bayo_interf_width, 0 ];
241 bayo_j = bayo_k + bayo_interf * [ 1/bayo_interf_slope, -1 ];
242 bayo_i = bayo_j + [ rivet_width + inside_rivet_gap, 0 ];
243 bayo_h = [ bayo_i[0], bayo_behind + bayo_gap + bayo_interf ];
244 bayo_g = [ bayo_m[0] - rivet_width, bayo_h[1] ];
246 bayo_e = [-bayo_p[0], bayo_p[1]] - [rivet_entry_width,0];
247 bayo_d = [-bayo_a[0], bayo_a[1]] - [rivet_entry_width,0];
248 bayo_c = bayo_d + [0,-5];
249 bayo_b = bayo_a + [0,-5];
251 bayo_f = [ bayo_e[0], bayo_g[1] + (bayo_e[0] - bayo_g[0]) ];
253 bayo_polygon = [ bayo_a,
273 cppxC = 0.41 * sm_inner_rad * TAU;
277 cpp_adj = (bayo_n[0] - bayo_f[0]) * (1 - sm_inner_rad / bayo_nom_rad);
278 // radius scaling due to nom and actual radius difference in
279 // bayo entry construction
281 cppa = bayo_f + [1,-1] * catch_pin_slop + [1,0] * cpp_adj;
282 cppb = bayo_g + [1,-1] * catch_pin_slop + [1,0] * cpp_adj;
284 - catch_pin_slop - catch_pin_slop_x_extra,
285 -catch_stalk_above_gap ];
286 cppi = [ cppa[0], cppd[1] ];
287 cppc = [ cppd[0], cppb[1] ];
288 cpph = cppd + [0,-1] * catch_stalk_h;
289 cppe = cppd + [0,-1] * (catch_knob_above_gap + catch_knob_dia/2);
290 cppf = [ cppa[0], cppe[1] ];
291 cppg = [ cppa[0], cpph[1] ];
292 cppB = 0.5 * (cppf + cppe);
294 echo("RR", sm_inner_rad / bayo_nom_rad);
296 // catch assembly depression below pin
298 cppy6 = cppB[1] - (catch_knob_dia/2
299 + (cppc[1] - cppd[1])
300 + catch_stalk_below_gap);
301 cpp7 = [ cppB[0], cppy6 + catch_cr ];
302 cpp11 = cpp7 + [1,0] * catch_cr;
303 cppy9 = cppy6 + catch_strap_width * 1/3;
304 cpp9 = [ cpp7[0] + catch_cr * 2, cppy9 ];
305 cpp8 = cpp9 + [0,-1] * catch_cr;
306 cpp10 = cpp8 + [-1,0] * catch_cr;
307 cppC = [ cppxC, cpp9[1] ];
308 cppD = cppC + [0,-1] * catch_strap_width;
310 // catch assembly stalk and so on
312 catch_cr3 = catch_cr + catch_stalk_h;
314 cppF = [ cppg[0] - catch_stalk_eff_bend_rad, cppd[1] ];
315 cpp4 = [ cppg[0] - catch_stalk_len, cpph[1] ] + [1,-1] * catch_cr;
316 cpp5 = [ cpp4[0], cppC[1] + catch_cr ];
317 cpp2 = cpp5 + [-1,0] * (catch_cr * 2 + catch_stalk_base_width);
318 cpp2r = cpp2 + [1,0] * catch_cr;
319 cpp2d = cpp2 + [0,-1] * catch_cr;
320 cpp3 = [ cpp2[0] + catch_cr + catch_cr3, cppd[1] - catch_cr3 ];
321 cppA = [ -cppxC, cpp9[1] ];
322 cppE = [ cppA[0], cppD[1] ];
324 catch_assembly_dy = -cppy9 + catch_strap_width;
327 module MainProfile(){
328 main_cnr_pos = [ side_thick, top_z ] - [1,1]*main_cnr;
331 translate(main_cnr_pos){
334 circle(r = main_cnr);
335 circle(r = main_cnr * 0.5);
340 polygon([[ -top_middle_dr, middle_bot_z ],
341 [ -top_middle_dr, top_z ],
342 [ main_cnr_pos[0], top_z ],
343 [ side_thick, main_cnr_pos[1] ],
344 [ side_thick, -side_height ],
345 [ side_taper, -side_height ],
348 [ -oring_x_rad, by_oring_z ],
352 translate([ oring_mid_dia/2 - main_dia/2, 0 ])
354 translate([ 0, oring_y_rad ])
355 scale([ 1/oring_oblate * (oring_compress_more+1) , oring_oblate ])
356 circle(oring_thick/2);
357 translate([ 0, oring_y_rad*2 - oring_thick/2 ])
358 circle(oring_thick/2);
363 module StrapLoopProfile(){
364 circle(r = strap_loop_thick/2);
367 module StrapLoop(){ ////toplevel
368 bigrad = strap_loop_inside/2 + strap_loop_thick/2;
369 extralen = strap_loop_thick * 5;
372 rotate([strap_loop_elevation, 0,0]){
373 for (x= [ -1, +1 ] * bigrad) {
374 translate([x, -extralen, 0])
376 linear_extrude(height= extralen + strap_loop_strlen + 0.1,
380 translate([0, strap_loop_strlen, 0]){
382 rotate_extrude(convexity=10)
383 translate([bigrad, 0,0])
386 cube([100,100,100], center=true);
390 translate([0, 50, 0])
391 cube(100, center=true);
395 module RotateProjectSlice(offset, slice_size, nom_rad, real_rad){
396 // nom_rad > real_rad
397 rotate([0,0, atan2(offset, nom_rad) ]){
399 translate([-offset, -10, 0])
401 linear_extrude(height= nom_rad*2, convexity=50)
403 translate([0,0, -25])
404 cylinder(h=50, r= real_rad);
405 translate([0,0, -25])
406 linear_extrude(height= 50, convexity=50)
408 [ -slice_size, -real_rad*2 ],
409 [ +slice_size, -real_rad*2 ] ]);
414 module RotateProject(x_min, x_max, slice_size, nom_rad, real_rad){
415 offs = [ for (i=[ x_min :
417 x_max + slice_size ]) i ];
420 RotateProjectSlice(off, slice_size, nom_rad, real_rad)
424 module BayonetCutout(){
425 RotateProject(bayo_c[0], bayo_i[0], bayo_slice_size,
428 translate([-0.5 * (bayo_a[0] + bayo_d[0]), 0])
429 polygon(bayo_polygon, convexity=10);
432 module ProfilesDemo(){ ////toplevel
433 translate([-10,0]) MainProfile();
434 translate([+10, -side_height]) polygon(bayo_polygon, convexity=10);
437 module LimitForHandling(){ ////toplevel
438 hull() for (r=[0,180])
442 rotate([0,0, rs * handling_angle/2]) {
443 translate([rs * xd * main_dia/2 * tan(handling_angle/2),
444 main_dia/2 + side_thick - main_cnr,
447 cylinder(r= main_cnr, h=50);
454 hull() rotate_extrude(convexity=10){
455 translate([ handling_dia/2 - main_cnr, top_z - main_cnr ]) {
456 circle(r = main_cnr);
457 mirror([0,1]) square([ main_cnr, 50 ]);
460 //cylinder(r= handling_dia/2, h=20);
463 module Cover(){ ////toplevel
464 render() difference(){
467 rotate_extrude(convexity=10)
468 translate([main_dia/2, 0])
470 translate([0,0, middle_bot_z])
471 cylinder(h= top_thick_middle, r = main_dia/2 - top_middle_dr + 1);
477 translate([0,0, -side_height])
479 rotate([0,0, r + asin((-oring_rm_beside) / (main_dia/2))])
481 oring_mid_dia/2 + oring_thick/4 * oring_rm_scale,
483 rotate([-oring_rm_angle, 0, 0])
485 cylinder(r = oring_thick/4 * oring_rm_scale, h=20);
487 for (r=[0 : 60 : 179]) {
489 height = top_thick_middle - brace_above_below*2;
490 translate([0,0, middle_bot_z + brace_above_below + height/2 ])
491 cube(center=true, [ oring_bore - brace_end_shorter,
492 brace_hole_width, height ]);
496 if (enable_head_cups)
499 translate([-implheadcup_large_dia * .5 - implheadcup_thick/2,
500 -implheadcup_large_dia * .0,
504 // translate(strap_loop_thick * [-0.5, 0, +1])
505 // translate([handling_dia/2, 0, -side_height])
506 // rotate([0,180,0]) rotate([0,0,90])
511 translate([0,0, -10])
512 cylinder(r= main_dia/2 - jig_rim, h=20);
515 module Jig(){ ////toplevel
518 translate([0,0, -side_height]){
519 cylinder(r= main_dia/2 + jig_thick, h= side_height + jig_thick);
521 translate([-jig_mark_rad, 0, jig_thick - jig_mark])
522 cube([jig_mark_rad*2, jig_mark, jig_mark]);
524 translate([0,0, -side_height-1])
525 cylinder(r= main_dia/2, h= side_height + 1);
527 translate([0,0, -rivet_posn])
529 translate([0,0, -100])
530 cylinder(r= jig_hole_dia/2, h = 200);
534 module CoverPrint(){ ////toplevel
535 rotate([0,180,0]) Cover();
538 module CoverTest2(){ ////toplevel
545 module CoverTest1(){ ////toplevel
549 for (r= [ 40, 147 ]){
551 translate([0,0, -10]) {
552 cube([ main_dia*3, main_dia * .53, 18], center=true);
556 // translate([ 50, 0, 0 ])
558 // strap_loop_inside + strap_loop_thick*2 + 1,
565 module ImplHeadCupTest(){ ////toplevel
572 module SomeStrap(width, cut_width=0){
573 // children(0) is to add, (1) subtract
576 cylinder(r=sm_outer_rad, h=width);
577 StrapMountProtrusion(smc_cnr_c_x + sm_closure_cnr,
584 cylinder(r=sm_inner_rad, h=max(width+2, cut_width));
586 StrapMountBolt(10, width);
588 cube([ sm_bolt_tighten_allow, 40,100 ], center=true);
593 module StrapMountBolt(l_delta, strap_width){ ///toplevel
594 // positioned relative to smc_pos
595 translate([(smc_bolt_nut_eff_thick - sm_bolt_head_thick)/2,
598 translate([ -sm_bolt_shaft/2-1, 0,0 ]){
599 rotate([0,90,0]) cylinder(r= sm_bolt_dia/2, h= sm_bolt_shaft+2);
601 translate([ -sm_bolt_shaft/2, 0,0 ])
603 cylinder($fn=6, r=smc_bolt_nut_dia/2,
604 h=smc_bolt_nut_eff_thick + l_delta);
605 translate([ sm_bolt_shaft/2, 0,0 ])
607 cylinder(r=sm_bolt_head_dia/2, h=sm_bolt_head_thick + l_delta);
611 module StrapMountProtrusion(half_x, max_y, cnr, width){
613 linear_extrude(height=width, convexity=10){
615 for (m = [0,1]) mirror([m,0,0]) {
616 translate([-(half_x - cnr), max_y - cnr])
618 translate([-half_x, -sm_inner_rad])
626 module StrapMount(){ ////toplevel
627 SomeStrap(sm_main_width){
629 StrapMountProtrusion(strap_loop_inside/2 + strap_loop_thick,
634 [0,0, sm_main_width] +
635 strap_loop_thick * [ 0, 0.5, -1.0 ])
642 module WallScrewHoleSlot(){ ////toplevel
643 ds = [-1,+1] * wm_screw_slot/2;
644 linextr_x_yz(-(wm_thick + 1), 1) {
648 circle(r = wm_screw_dia/2);
653 translate([0, d, 0]){
655 circle(r = wm_screw_head/2);
656 linextr_x_yz(-(wm_screw_head - wm_screw_dia)/2, 0)
657 circle(r = wm_screw_dia/2);
663 module WallMountMounts(){
664 linextr(0, wm_z_max){
665 translate([ -sm_outer_rad, 0 ])
666 rectfromto([ 0, -wm_y_max ],
667 [ wm_thick, wm_y_slot1_max ]);
670 module WallMountScrewHoles(){
671 translate([ -sm_outer_rad + wm_thick, 0, wm_z_slotc_screw]) {
672 translate([ 0, wm_y_slotc_screw, 0 ])
674 translate([ 0, -wm_y_slotc_screw, 0 ])
680 module WallMount(){ ////toplevel
681 SomeStrap(sm_main_width, wm_z_max + 2){
683 WallMountScrewHoles();
687 module WallMountBaseRingCut(){
688 circle(r = wmb_mount_cut_rad);
691 module WallMountBaseMounts(){
692 linextr(0, wmb_z_max) {
694 rectfromto([ -sm_outer_rad, -wmb_y_mount_max ],
695 [ wmb_x_outer, +wmb_y_mount_max ]);
696 WallMountBaseRingCut();
701 // screws, nuts, slots for nuts to go down into
702 module WallMountBaseScrewsEtc(){ ////toplevel
705 translate([wmb_x_screw, 0, wmb_z_screw]) {
706 linextr_y_xz(wmb_y_screw_end,
707 wmb_y_screw_end + 100) // XXX change 100
708 circle(r = wmb_screw_dia/2);
709 linextr_y_xz(wmb_y_screw_end + web_screw_len,
710 wmb_y_screw_end + 100) // XXX change 100
711 circle(r = wmb_screw_head_dia/2);
712 linextr_y_xz(wmb_y_nut_min,
713 wmb_y_nut_min + wmb_nut_th){
716 circle(r = wmb_nut_rad, $fn = 6);
717 translate([0, 100]) // XXX change 100
718 square(wmb_nut_across, center=true);
726 module WallMountForBase(){ ////toplevel
727 SomeStrap(sm_main_width, wm_z_max + 2){
730 WallMountBaseMounts();
733 WallMountScrewHoles();
734 WallMountBaseScrewsEtc();
739 module WallMountBase(){ ////toplevel
742 linextr(wmbb_z_min, wmb_z_max) {
746 rectfromto([ -sm_outer_rad, wmbb_y_max - wmb_mount_y_width ],
747 [ wmbb_x_outer, wmbb_y_max ]);
750 WallMountBaseRingCut();
757 module WallMountForBaseDemo(){ ////toplevel
759 color("blue") WallMountBase();
760 %WallMountBaseScrewsEtc();
763 module CatchAssemblyCoreProfile(){
767 translate(cpp3) circle(r= catch_cr3);
786 translate(cpp8) circle(r= catch_cr);
789 translate(cpp4) circle(r= catch_cr);
790 translate(cpp5) circle(r= catch_cr);
791 translate(cpp7) circle(r= catch_cr);
799 translate(cpp2) circle(r= catch_cr);
801 // if cpp11 is above cpp10, the subtracted hull above
802 // can go down too far. Ensure we do not cut off below cppy6.
807 [ cpp7[0] - catch_cr, cppy6 ],
812 module CatchTipProfile(dy){
817 // circle(r = dist2d(cppF, cppd));
818 //circle(r = dist2d(cppF, cppa));
829 module CatchHeadProfile(){
839 module CatchCore(){ /////toplevel
840 linear_extrude(height=catch_strap_thick, convexity=10)
841 CatchAssemblyCoreProfile();
844 linear_extrude(height=catch_head_th, convexity=10)
846 linear_extrude(height=catch_tip_th, convexity=10)
847 CatchTipProfile(catch_tip_th - catch_head_th);
850 linear_extrude(height=catch_head_th, convexity=10)
853 translate(concat(cppB,[0])) hull(){
854 translate([0,0, catch_knob_height + catch_head_th - catch_knob_dia/2])
855 sphere(r = catch_knob_dia/2);
856 cylinder(r = catch_knob_dia/2, h = 0.1);
860 module CatchPreDistort(){ /////toplevel
861 scale(100 / sm_inner_rad)
866 module CatchAssembly(){ /////toplevel
867 rotate([0,0, -(cppe[0] + cppB[0] + catch_pin_slop) / sm_inner_rad * 360/TAU])
868 translate([0,0, catch_assembly_dy])
869 scale(sm_inner_rad / 100)
870 import(str("poster-tube-lid,CatchPostDistort-fa",
875 SomeStrap(catch_strap_width){
878 translate([-200, -200, -200])
879 cube([400, 200, 400]);
884 module CatchDemo(){ /////toplevel
885 color("blue") translate([0,0,
889 translate([0,0,+side_height
894 module CatchDemoS(){ /////toplevel
895 color("blue") translate([0,0,
900 translate([0,0,+side_height
903 mirror([0,1,0]) translate([-250,33,0]) cube([500,500,500]);
907 cube([6.15, 2,2], center=true);
910 module CatchPinProfileDemo(){ /////toplevel
911 translate([0, 0 * -bayo_behind,0]) {
913 bayo_n[0] - bayo_e[0]);
914 color("blue") translate([0,0,
917 CatchAssemblyCoreProfile();
924 polygon(bayo_polygon, convexity=10);
926 // adhoc show a position
931 )) difference(){ circle(2.5); circle(2.0); }