These will be joined to make the footboard panel. I tried to explain to my wife that I should use plywood but to no avail. The allowance for movement should be from side to side right? Please forgive the foggy photo.
It would be a monumental mistake to put a solid wood panel in the headboard and footboard especially if you glue it in. In the next 20 years the wood will shrink from 1/8" to 1/4". A large panel like that never just shrinks evenly even if it's just floating in a dado, it splits open. The finish you put on the wood ends up gluing it in to a certain extent. Then if you mortise the end pieces to accept the panel when it shrinks there would be a white line where the wood wasn't stained. Plywood was advised for a very good reason. If you just have to use solid wood it would hold up better to run the grain horizontal. By doing that the panel has only 2' of width to contend with. The shrinkage would be less.
We have an "antique" bed from the 1930s, probably made in Belgium. It has two large solid wood panels on the headboard and footboard. One of the panels has a split in the headboard. It split a long time ago, in exactly the way that @Steve Neul described.
* Closeup of Split in Headboard
if the same fabrication methods are used for large horizontal table tops,
why won't it work for a vertical project of the same nature ?
(just thinking out loud here).
I talked to a company one time about making tables. First thing they mentioned is all would must be accimated and stabilized for one year prior to assembly...Takes money to make money... I was out....
I also went inside a table and chair manufacturing plant off I-35 in Kansas City. We went in the side to buy some pedistal for a furniture company I worked for in the early 90's. There was stacks of chars and tables with flaws sols once a year as defective units. Not everything is perfect in a productive world...
Here's the footboard. each panel is roughly 12 inches square. I have the following options:
-Install them loose in the groove, butt ended against the post (with or without biscuits).
-Glue them all together (with or without biscuits), butt ended against the post.
-Either one grooved into the post.
Laid it out on the assembly table. At the risk of getting laughed at, that is the cleanest this table has been since it was built about 7 years ago. It will also be the first time anything gets assembled on it.