As a general rule, you want the direction in which the wood moves the most to be aligned to the shorter dimension. So, in the drawing, the floor board is illustrated as I would suggest the grain should run - the end grain of the board is against the short sides of the box. The Japanese often do drawer bottoms with the grain running the other way but I've always thought that a bad idea -feel free to experiment however!timoore wrote:How does the grain run in the floor? I can see that it is drawn running the length of the chest in SketchUp, but I've heard of it being done cross-ways and then ship-lapping the boards together.
It entirely depends upon how heavy the contents are, and what wood you are using. I don't like boxes with flimsy bottoms, so I perhaps go slightly towards overkill in specifying things. Also, the thickness of the panels relates not only to the loads that are placed upon the panel, but to whether there is joinery. If there was no joinery involved, most of the dimensions of this box in terms of individual piece thicknesses would slim down - probably the bottom panel and sides would be .375" (9.6mm) instead of 0.5" (12.7mm). If you were using wenge or bubinga panels, then the same slimming would be wise - if you used basswood, or soft pine, probably you might want to think about thickening the parts by 1/16" (1mm) or so.Does the floor actually need much in the way of support, other than on the edges?