Ok among other things I have plans to build is a decorative display for some of our baseballs. Being a round object they will roll off the display, so I thought I would maybe make circles where I wanted the balls to sit but have no clue how I would do this. I have router, dremel and a tablesaw for use. Is there some sort of a router bit that will remove a 3 inch circle or am I out of luck?
yes there are several ways to cut a circular disk for the ball stand. I think that I will stick with the router approach as it is the safest and arguably the best.
What you will have to do is to build yourself a router circle jig. There are a ton of easy designs to had on YT and if I am not mistaken Colin has a jig video that includes a circle jig for a router.
Just find a design that is easy to build from scrap wood. Do you have any type of disk sander or belt sander ?
There are Bowl bits for the router which would help with putting a depression on the top portion of the circle to keep the ball in place and allow you to still be able to handle it for dust etc. If you decide to hollow an area out just ensure you preform this before cutting the circle out. The reason for this is to have a large piece of material to be secured while you remove the material then you can cut the circle out. if you try to accomplish this using a small round piece of material you are asking for trouble so just think it through and be safe.
Another way to cut a circle out is using a jigsaw. There are tons of these kicking around in yard sales and flea markets so keep a look out.