Demilune Table, Part 1: Design Considerations

We need a small table as a plant stand in front of the kitchen window.  The current table, borrowed from my sister, has two thick books on it to raise the plant to the height we wanted.

Not the ideal situation

I've wanted to make a Demilune table for many years.  So, not knowing any of the pitfalls of the design, I decided to jump in.  Soon, I started to realize all the complications.  There's the position of the front legs.  There's the rotational orientation of the legs.  There's the joining of the legs to a curved apron.  There's making the curved front apron without wood bending capability.

One of the questions fortunately had an easy answer, though there was some butt scratching about it.  Half-oval or half-round?  I love an oval shape, but we had decided the table needs to be about 24" wide and 12" deep.  That makes it a perfect half-round.

In this post, I'm going to walk through some of the design considerations.  This is as much to show readers my thinking as it is for me to work it out in my head.

I have a copy of Bill Hylton's excellent "Illustrated Cabinetmaking", and he's got a two-page section on demilune tables.  I could make this ultra-simple by going with a three-legged table having no curved apron, or I could challenge myself and try something tougher with curved front apron attached to legs.  My biggest challenge is how to make the curved apron, and I'll get into that more later.

Started with the plan view of the half round top

I thought it should have a 1" overhang of the top all around.  The legs will be a little proud of the aprons, so the 1" is from apron to edge of top.

Showing where the aprons will be

The position of the back legs is simple enough.  They'll be at the back corners, with the rear apron mortised into their inside faces and the curved apron mortised into their front faces.  But the front legs are another story.  I tried a couple different orientations.  This first one is with the legs at 45° angles relative to the rear edge of the top.

Front legs drawn, centered on lines 45° from back edge of top

A front view with the legs at that 45° position

It seemed to me that the front legs were not forward enough for front-back stability, so I tried legs at 60° from the top's back edge.

Front legs, centered on lines 60° from back edge of top

A front view with the legs at that 60° position

I liked this a lot better.  The picture in Hylton's book shows the legs closer to this position as well, though it doesn't give any details.

One might notice that the front surfaces of the front legs are parallel to the apron (or parallel to the tangent to the apron at that point), as opposed to being parallel to the back edge of the top.  This is a detail that I'd seen in Hylton's book as well as most online images.  This has advantages for joinery using a laminated apron, but might create issues for other methods.

Hylton shows different ways to work with the curved apron.  One could make a single-piece apron (OK, it's laminated, but one long laminated piece), mortised into the rear legs and joined to the two front legs using bridle joints.  The curved apron could be made via bent lamination, or by using the "bricklaying" technique, building the curve from vertically laminated and offset  pieces that are then cut on a bandsaw and finally veneered.  I don't have a bandsaw, and for various reasons I don't want to laminate the semi-circular full apron.  So I'm going to attempt to make this like I would any rectangular table: with the aprons having tenons that fit into mortises in the legs.

The legs shown above are 1.5" square, though I'll be tapering the legs down to 1" square at the bottom.  I had originally drawn them up at 2" square, but they just looked too big and chunky.  The choice of 3" wide for the apron was not totally random.  The legs will be 28 1/4" long and are only joined via the aprons, so the aprons needed to be reasonably wide.  The 3" aprons in the sketches above and below looked about right, and I think they'll give enough support, so that's what I'll go with.

3" aprons

4" aprons

Update: I've been experimenting with joinery and think I need to make the legs thicker at the top to accommodate longer tenons.  Here's a picture with 1 3/4" square legs that taper to 1" at the bottom.

The table with thicker legs

Unfortunately, it still looks a bit clunky to me.  But I need the mortises and tenons to be deep and long enough not to fail.  I'll get into that more next time.