OK. I'll see what I can get for you.
Fred, I thought I'd replied already, but apparently I didn't post what I'd typed before. The owners-to-be are actually going mattress hunting this weekend, and they're still undecided about whether to get a standard western style mattress or a futon/shikibuton. In either case, it defintely makes sense to leave the internal dimensions open enough to allow for needed finger/reach space. Effective design in this case includes consideration for OEM tolerances and variances when you have to build something that integrates with someone else's products.
Mike, the side and foot rails are 1 in. thick. The cleats on the inside of the side rails are 3/4 in. thick (forms a 3/4-in.-wide ledge for the slats to sit on. The central rail is 2-1/4 in. wide
Thank you, Dave. From the pictures you'd provided above, I would have guessed those rails were more towards 1-1/2". I feel better now about going with 1-1/4" but will let my eyes make the final decision.
Last edited by Mike Ontko; 05-20-2015 at 12:15 AM.