King Bed Headboard - Part 1: Design

I'm finally getting to a honey-do project that's been on the list for a while.  We've wanted a headboard for a long time and finally I'm ready.  And I'm planning to incorporate a piece of purpleheart (peltogyne spp.) that my my wife gave me several years ago.  Fortunately, neither of us likes overly fancy things, so this will be relatively simple.

The first thing to do was to take some measurements and get a general idea of what we wanted.  The bed is a king", 76" wide.  I decided on rails that are 72" long (plus 2" long tenons at each end) and posts that are 3" wide, making the overall width of the headboard 78".

Sketchup model of the bed frame, mattress (including box springs) and pillows

The top of the mattress is about 27" above the floor.  This guides where I'll place a lower rail - if it's too high, then the pillows can slide right under the rail and that's no good.  So the lower edge of the lower rail will be about 22-23" above the floor.

Rear view showing placement of lower rail

A headboard can be a fairly simple thing.  In my case I'm planning to have two rails connecting the upright posts, and was thinking about vertical, variable width slats between the rails.  But there are still a lot of design choices to make.

An early version: straight upper rail even with top of posts, with cap piece over the whole
(I started experimenting with the positioning of the purpleheart and cherry slats)

Another design option had a curved top edge of the upper rail, in which case a cap piece wouldn't make sense.  I had an idea to cut out a design in the center slat, that ultimately didn't get included.  Good thing, too, as this purpleheart is danged hard stuff and a design would have been tough to cut and shape to the lines.

Alternate design with curved top rail and different arrangement of slats

We both liked the curved top better than the straight top.  With designs where the posts end higher than the top rail, there is an opportunity to add some decoration to the top of the posts.  Here is one option.

Chamfered top edge and an applied bead detail

I liked this idea, but it was nixed by the wife, so back to the drawing board.

Another option that got rejected - I tried a few different profiles

I liked this idea too, but she didn't care for it.  In the end I decided to go with a simple chamfer all around the top.  Here's the final design.

The final design: curved upper rail, chamfered post tops, only three purpleheart slats

There are a lot of other things to think about when considering the design.  One of these is overall thickness and width of parts.  Mostly I relied on Sketchup to help with that.  If it looked good to my eye, then it was OK.

The posts ended up at 51" tall, 3" wide and 2.5" thick.  I originally wanted them 3" thick, but the stock I purchased will only give me 2 1/2" when laminated together.  The rails are 72" long (plus 2" tenons on each end), 8" wide and 1" thick (see below for a not on thickness).  The slats were governed by the length of the purpleheart board.  I had enough length to give me three pieces that were 12" long.  So the slats will be 11 1/2" long (plus short stub tenons), variable widths (8", 5" and 2 1/2") and 3/4" thick.

The rails will be set back from the front of the posts by 1/2" to 3/4".  And the slats will be set back from the front of the rails by 1/8".

As far as joinery is concerned, I plan to use a double tenon at each end of the lower rail into mating mortises in the posts.

Lower rail tenon detail

The upper rail will have single tenons.  The curved upper edge drops the ends to 5" wide from 8" at the center.  So those tenons will be 4" wide.  The slats will have short stub tenons going into mating mortises.  That's 22 shallow mortises in the rails.  I thought about running a groove on the edge of the rails instead of chopping all those mortises, but I think filling the spaces between slats would end up looking bad.

OK, this is hindsight now - I've already purchased and started working on the project.  I should have specified 1 1/2" finished thickness for the rails.  I think that would have been a better fit for the size of the posts.  I bought 5/4 stock for the rails (which had been partially surfaced, making the actual thickness about 1 1/8"), but after planing out some twist and bow, I'm getting just under an inch thickness.  Live and learn ...