how to make two same shapes connected in Illustrator

Question

I will begin with explaining the purpose of what I want to achieve or it would not make any sense why I'd want it.

So I work with cutting plotters and use illustrator for designing. There are several types of vinyls (with different thickness and other properties) and for one specific vinyl, the proper way to cut is, cutting a shape twice without lifting the pen/blade up. Like for a circle with 4 anchor points, blade goes from A->B->C->D->A->B->C->D->A

But I cant find any easy way to do it. I was able to make such a circle with a lot of trouble, you can look at it in the picture.

But again thats just circle, I need to make other shapes as well.

So any help please?

Answer 1

Like i said you can script this. Below is a script that duplicates the points of all selected paths on top of each other. Please note that I do not make any sanity checks user beware.

#target illustrator

var doc = app.activeDocument;
var sel = doc.selection;

for (var s = 0; s < sel.length; s++ ) {
    overlayPoints(sel[s]);
}



function overlayPoints(path){
    var pts = path.pathPoints;
    var len = pts.length; 

    for (var i = 0; i < len; i++ ) {
        var pt = path.pathPoints.add();
        pt.anchor = pts[i].anchor;
        pt.leftDirection = pts[i].leftDirection;
        pt. rightDirection = pts[i].rightDirection;
        pt.pointType = pts[i].pointType;
    }    
}

Answer 2

Let's assume you have now only one shape.

• select your shape
• take the scissors tool and cut the shape path at some anchor point Deselect all after cutting, because there's a part of the path selected and that can spoil the next selection.
• duplicate your shape(=select, copy, paste in place); let's call A=the original and B=the copy on the top
• take the direct selection tool and select the cutting point.
• move the selected point one tick with the arrow key

The uppermost of the four points at the same place will be selected. You can control what point is selected by locking one shape in the layers panel and, if needed, moving one anchor point temporarily one arrow arrow tick away to acces the lower one.

• select A and B, join them (Ctrl+J)
• select the moved control point and move it back with the opposite arrow key

If needed, select the shape and join it to have a closed shape.

BTW. It can be useful to ask is it possible to program the cutter to go twice around a loop?