As Tom said there are router sleds and router skis, both of which can be searched on this forum. One member attached a right angle bracket onto a radial arm saw and if I ever see a cheap radial arm drill for sale I'm going to snag it and try using it for one. There are also horizontal mounted routers and they have their own advantages in that position. Mark Sternberg I think it was also made a multi positional design which you might find on this forum (the post is a few years old) but it might be on youtube too.
Someone I consider a master woodworker once told me that a master woodworker is not someone who never makes mistakes. He is someone who is able to cover them up so that no one can tell.