MOTM

>Wood, especially solid wood, contracts and expands quite noticeably across its
>length with changes in humidity. Plywood does not, since it is made by laying
>cross-grained wood sheets down in layers. So while solid walnut would work
>well on the ends of a cabinet, I'd be real careful about using it across the
>length of the front or back. Across a four length you could see movement of
>a quarter inch over a year. They do make hardwood veneered plywood, and you
>might consider using that for backs, and possibly fronts, if you put solid
>wood trim strips to hide the laminated edges.

Actually, solid wood is fairly stable over its length (with the grain) 
but moves quite a bit over its width (across the grain). Since the depth 
of the cabinets will be only 10 or 12 inches, it shouldn't be a big deal, 
and anyway only affects the module clearance in the back of the cabinet.

>I have a good friend who is a professional woodworker who grew up in 
>Hungary and learned woodworking the old fashioned way.  He likes to 
>make cabinets with walnut plywood.  He cuts edging material about 
>1/8" thick on a table saw out of solid walnut and glues it on after 
>making sure the edges are perfectly smooth by using a joiner.  He 
>also always uses solid wood for trim, but uses plywood for any large 
>or long pieces such as sides or tops.  
>It can be done using solid pieces, but I'm not sure of the 
>technique.  Something to do with gluing together several strips with 
>grain running in opposite directions using biscuits.

This is done to counteract the wood's tendency to warp or cup, not for 
shrinkage issues. Again, with a 12 inch depth, warpage should be fairly 
minimal in a properly designed box.

There are plenty of good reasons to use plywood; it's easier to work with 
and cheaper, for starters. But solid wood should work very well for this 
kind of cabinet if it is well designed.

nathan