How do I cut holes in a piece of metal?
There is no direct menu item for cutting a hole in a polygon. However, there are several ways you can do this. The best way to explain is with an example. Let’s say you want to draw a square patch of metal with a square hole in it:
Method 1: The above metal was drawn as a single polygon. You can think of it as an open polygon like this:
The only difference between this and the previous picture is that this one has a gap.
Method 2: Another way to cut a hole in a polygon would be to draw two separate polygons as shown below:
Method 3: There is another method you may wish to use if you already have a piece of metal drawn in which you want to put a hole. For example, you start with a square as shown below:
You can then divide the square into two polygons using Edit => Divide Polygons. In this case, you could draw the dividing line on the left side which would result in two polygons like this:
You could then continue to divide the polygon until you had a square polygon in the middle representing the metal you want to remove:
You can then easily delete the middle polygon resulting in a hole in the middle of the square:
You may then use the Edit => Merge Polygons command to get a single polygon like this:
This method is a little more difficult, but usually results in less subsections (and thus less memory), because there are less polygon divisions.
Method 4: Another method is to use the Merge Polygon function to accomplish this task. To do this, first create a new metal type which has more loss than any of your existing metal types (for example, set the conductivity to 1E-9 and use a small thickness). Then create two polygons, one which represents the outer outline of your desired shape and one which represents the inner outline. In the example below, the larger square represents the outer outline, and is set to the new lossy metal type. The smaller square represents the inner outline of the desired shape:
Next, drag the smaller polygon inside the larger polygon to the desired location. Select both polygons and select Edit => Merge Polygons. This changes the outer polygon so it no longer contains the metal of the inner polygon:
Finally, delete the inner polygon to give the final shape:
Method 5: For regular polygons, you can use a donut. Select Tools => Add Metalization => Donut and fill in the parameters. By using a Start Angle of 0 degrees, an End Angle of 360 degrees and 4 sides a square with a hole in the middle is created. You use the Outer radius to define the size of the polygon and the inner radius to define the size of the hole.
