Has anyone made a design with a fixed roller chain and a rolling sprocket. The idea is to use this in place of a rack and pinion for a relatively long carriage travel of 40 feet. The chain would be fastened every few feet to a support member.
Yes, but it isn't typical to fasten the chain. The problem is that sprockets are designed to have the chain wrapped a large fraction of the circumference to prevent the chain from camming out. Look at the way that chain drive gate openers work.
I'd recommend something more like this pic. This concept has one belt fixed along its whole length that meshes with the upper belt that the motor drives against. However, if you're moving relatively slow (which I assume you must be or the roller chain thing wouldn't work either), you could just anchor the belt at both ends. I suppose you could do this same sort of thing with a chain and sprockets, but you'd have awful backlash.
Tsubaki is a valuable resource - I highly recommend them and their products. I have used their pin gear chain and sprockets. Note that the sprockets are special, with a truncated tooth, so don't assume that any sprocket will work. It may be possible to make any sprocket work, but one would need to understand the system.
Yes it is not uncommon. You do not have to have any wrap. Roller chain will have more stretch than a gear rack. You can tack-weld the chain to a plate.