BOSL2/tutorials/Attachment-Parts.md

Prev: Using attach()

Attachable Parts

Some objects provide named attachable parts that you can select instead of using the main geometry for the object. One important kind of attachable part is the inside of a tube.

Here is a tube with its anchors shown:

include<BOSL2/std.scad>
tube(id=20,h=15,wall=3)
  show_anchors();

The anchors are all on the outside wall of the tube and give you no method for placing a child inside the tube. In order to attach inside the tube, we select the "inside" part using the attach_part() module.

include<BOSL2/std.scad>
tube(id=20,h=15,wall=3)
  attach_part("inside")
    align(BACK,TOP)
      color("lightblue") cuboid(4);

Now when we align the cube to the BACK wall of the tube it appears on the inside of the tube. If you need to attach to both the inside and outside you can place some attachments using attach_part() and some with the standard attachment geometry on the outside like this:

include<BOSL2/std.scad>
diff()
tube(id=20,h=15,wall=3){
  attach([1,-1/2],BOT)
    color("green")cyl(d=4,h=3,$fn=12);
  attach_part("inside"){
    attach(LEFT,BOT,align=TOP)
      color("lightblue")cuboid(4);
    attach(BACK,CTR,align=TOP,inside=true, inset=-0.1)
      cuboid(4);
  }
}

Next: Using Color with Attachments