I was researching a roller rotary, Algolaser, in order to do a help thing. On their site, I found a unique application for the rotary. It was turned upside down so the rollers moved it in the Yaxis direction. On top of the bottom was a skateboard being engraved. So what they did was turn it over and use it as a traveling table. Out of the box thinking!
Not sure which roller rotaries can do this, but I know my Atezr KR can do this because the rollers stick up higher than the rotary frame and motor. With the supplied 4-wire cable, I could get about 2 feet of travel in each direction. If I had the room. 
