Thanks everyone, but this little plotter is definitely not my idea. There are literally hundreds of tutorials online showing how to build this. I am pretty proud of being able to make it, though. I hardly know anything at all about electronics or coding. So it's still a decent accomplishment for me
I have almost have the software squared away on the bigger version. I am currently plotting out a test pattern, measuring, adjusting the code, then repeating until I get it as close as possible.
Here is the swivel blade I am going to try first:
Swivel Knife with 2-Refill Blades | Hobby Lobby | 430819
Here's a picture of the bigger plotter, and a sample plot from the mini plotter...