Two hobbies collide as I print something super nifty for my wood habits.  A cool thing you can do with router tables is apply a template onto wood, and use a templating bit to match cut.  The bit has a bearing of the same diameter as the cutting edges.  It rides against your template and cuts away any underlying wood that isn’t shaped like your template.  Super handy, but you need a good template to start with.  Enter the 3D printer.

I modeled up this little jig so that it hooks onto the edges of a board and gives an exact radius.  It is hard to see given the color, but I printed a 1″ text in the bottom to note the size of the radius.

Here is a picture of the jig fully seated, and what the resulting cut looks like.  Very clean and smooth.  The large circular cutout gives a lot of finger purchase so you can hold it tight and far away from the spinning bit.

One concern I had was with the material.  Would the cutting friction heat up enough to melt the plastic.  I did 4 cuts on a 3/4″ bit of plywood and everything looked good.  If I had a hundred corners to do, I would worry.  I could always upgrade to PETG.

The part is available in multiple sizes on thingiverse