Very cool. This method would be cool for larger circles. I like how you cut the plexiglass also. I just had to make a couple of 18" (had to be perfect) wood circles for someone. I used a jigsaw to cut the circle a little proud of 18 then used a wood lathe to get it down precise. It turned out good, but took a while. Next time I'll try this.

Just an idea, but one could even make an "auxilary" tabletop with one of those stickon rulers and a slot to slide the bolt in for a quick setup for different size circles. 2" would = a 4" circle, 3" = 6" circle, ect...

if you were to make a table saw sled you could do the circle cutting without having to drill holes in your table...