...boy, you guys are alot faster than me! I've always made my bookcases with a fixed center shelf...at least the longer ones. The time it takes to dado and install the shelf, true, isn't that much, but then you have to factor-in the extra piece in the faceframe and all that goes with it...as an aside, I usually finish the case before installing the back; it makes for better/easier spraying...shelves always get at least an 1 1/2" hardwood strongback/face.
cg
I made some bookshelves about 35 years ago, three 6' high by 3' wide, doug fir plywood and pine (I think?) edging -- not face frames. I did fix the centre shelf (dado & glue), but the verticals eventually bowed out and the shelf still came apart as I jammed books in.
So today I would use a sliding dovetail instead of a simple dado.
This is my experience. Now the face frame might change things. But I would still fix the centre shelf.
YMMV
Luigi
would still fix the centre shelf.
I'd use 3/4" side panels with 3/16" deep dado and then install 3, #12 x 1, FH, coarse thread sheet metal screws bunged with 1/4" bungs to hold shelves.
No cross grain glue joints, screws keep sides from bowing, dado handles book load in shear.
It's a win/win situation.
Lew
Burn an X in the bungs with a soldering iron. When people ask about them say, "What? You never saw a wood screw before?" ;)
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