/* Wooden Toy Train Connector for OpenSCAD mailing list.
   Target Shape: A gym dumbbell
   Model Version v3 2024-01-05
   Error Messages:
     OpenSCAD-2024.01.03.ai18006-x86_64.AppImage
       WARNING: Warning: mesh is not closed!
       WARNING: Warning: mesh is not closed!
       ERROR: Rendering cancelled by exception Unauthorized intersections of constraints
     OpenSCAD-2023.03.05.ai13734-x86_64.AppImage
       WARNING: Warning: mesh is not closed!
       WARNING: Warning: mesh is not closed!
       [fast-csg] Performing safer but slower nef operation instead of corefinement because operands share some vertices. (can override with fast-csg-trust-corefinement)
       ERROR: CGAL error in CGALUtils::applyUnion3DHybrid: CGAL ERROR: assertion violation!
       Expr: e->incident_sface() != SFace_const_handle()
       File: /usr/include/CGAL/Nef_S2/SM_const_decorator.h
       Line: 329
       WARNING: No top level geometry to render     
*/

total_length=34.25;
mysquare=5.75;
mycircle=11.0;
total_height=11.95;

$fn=100;

module basic_shape_2d(){
  translate([total_length/2-mycircle/2,0]) circle(d=mycircle);
  translate([-total_length/2+mycircle/2,0]) circle(d=mycircle);
  square([total_length-mycircle,mysquare],center=true);
}

intersection(){
  //bounding box
  cube([total_length,mycircle,total_height],center=true);

  //dumbell with roof() exceeding its bounding box
  union(){
    translate([0,0,total_height/2*0.8]) roof() basic_shape_2d();
    translate([0,0,-total_height/2*0.8]) linear_extrude(total_height*0.8) basic_shape_2d();
    translate([0,0,-total_height/2*0.8]) mirror([0,0,1]) roof() basic_shape_2d();
  }
}