She wanted the bed to be low, with no box spring, so we went with a platform design. She also wanted to be able to move it around without too much trouble, so, the casters.
To keep the cost low, I built it out of standard dimensional lumber. It has a headboard, footboard, side rails and a plywood platform with extra support feet in the middle.
I used the through-bolt system for the attachment points. Each side rail has a long threaded bolt centered in the end, and a wood dowl above and below it. The bolt enters the end post of the head and foot boards and is pulled tight with a washer and nut from the out side. In the pics you can see the hole for the nuts in the corner posts. I usually cover these with a brass rosette, but I forgot them when we took the bed up.
Around the inside of the headboard, footboard, and side rails is a 1x2 support strip for the edge of the platform to rest on. The platform is in two pieces, so that I didn't have to wrestle a queen size sheet of plywood up to the third floor.
A center support runs up the middle of the bottom of the platform, and four posts support it to ensure that there is no bowing.
The stain is minwax Ebony, with a finish of four coats of satin polyurethane. The weather was hot and sunny when I was finishing this bed, and I like to use the sun to "bake-on" each coat of finish.
I set up a pair of ladders in the back yard and ran plywood sheets through them so as to hold the pieces up facing south. I like to make sure the finish is thoroughly mixed and warm and thin before applying it. It also helps if the wood is warm as well. This gives you a nice even coat that doesn't harden too soon.
I also sand lightly between coats, the end product has a much smoother feel if you take the time to do it right.
A final hand rubbing with a sheet of corrugated cardboard, ripped into two sheets, gives you just enough abrasion to bring up a nice shine.