I was asked "What does it take to scan the edge of a casino chip?"
Well, it takes a lot of patience. A spirit level helps too. A spirit level is also known as a bubble level or carpenter's level.

Both the length and width of the glass bed should be level. The picture below shows how the scanner glass bed must be level or the chip will keep rolling to one side.
In the picture the scanner starts from the right and travels to the left. I've placed the chip sideways so the scan is a short distance. The scan seems to turn out better this way.

The next step is to make the room dark. This makes the background around the chip black. You can attempt to scan when there is light and see how it turns out. There are reflections from my ceiling when the room is lighted so I make my room dark when I scan with the lid open for a black background.

Try a chip edge scan with a CIS type scanner and see what the results are. Be sure to choose a chip with edge markings, preferably one that stands on edge.