I have used one of these pantograph shape cutters, and they work well, and will cut out any shape that you make for a pattern.
The pattern goes in the top, and a rubber belt allows the motor driven arm to follow any shape.
This is a great machine for making multiple parts of the same shape. You can cut stars, ovals, or any other shape.
Some of these machines are quite complex, but the simple ones also work well, and you could easily make one of these. The only motor you need is the one right above the torch, and is is a slow gear driven motor. You need a rubber belt to go from the motor to the central axis of the pattern, to hold the knurled motor shaft against the pattern.
Pat J