Drill chuck adapter for common routers?

I have a project coming up that is going to require a ton of small holes in several different sizes. Do they make drill chucks that can be attached to the standard routers often used on hobby mills? It'd be nice if I could just use the regular hardware store drill bits I have laying around, rather than having to go out and buy bits that have the 1/4" or 1/8" shank needed to fit my collets. Does such a thing exist? Without being prohibitively expensive?

I assume there would be some precision lost going this route, but thinking it won't be enough to stop this project.