This piece guides the router; the factory edges guarantee that your top will be square. If your mortises are centered, go ahead and cut all of them. Have a look on its image and you can take further guidance from me.
You should be careful while making it. Drilling the screw holes for fastening the baseplate to your router is a precision job, though, particularly if you want the bit to be located exactly in the center.
When I saw this wooden bench and instantly I think that it must buy this for my garden. For your comfort level choose the best wood for making this project. This oak book stand made with two matching halves keeps your beloved books in one place. It is made with sturdy wood so you can fully sit and relax on it.
You can share these ideas to others wood workers too. Using just one bit, you can make four different dados.