Mortices and tenons for hexagonal table

[edmund]

Hi everyone,

I'm planning a hexagonal occassional table and am trying to work out the best approach for the tenons for the aprons and the mortices in the top of the legs. As there will be six legs and aprons if I use mortice and tenon joints the angle relative to the top of each leg (which will be square) will be 30/60 degrees. So, should I (i) angle the tenon to fit a mortice that will be perpendicular in the top of the leg, or (ii) cut an angled mortice with the tenon following the line of the apron? I was thinking of (i) but I'm not sure I'll have enough wood for a sufficiently long tenon because of the angles involved.
Any alternative jointing suggestions would also be gratefully received.
Thanks, Edmund

 

[Steve Maskery]

Hi Edmund
Personally I wouldn't use angled tenons for such a severe angle. 5 degrees on a chair is one thing....

Does the leg have to be square? I once made a little octagonal table where the legs had 5 sides. There was one face towards the centre of the structure, two faces out at 22.5, then two at 90 to them.

I think.

At each leg the rail was turned through 45 deg, but the rails were straight in line with the face, so the tenons were not angled. You could do the same with a hexagonal table, I think.

Failing that, I'd cut angled mortices, but getting the shoulders good is more difficult. ACtually I'd probably use loose tenons, at least it's easy to get a clean face.

HTH
Cheers
Steve

 

[MikeW]

As Steve mentions at the bottom of his post, regardless of how I ended up shaping the legs, I would use loose tenons.

Happy New Year...

Mike

 

[jasonB]

As steve says I would go with loose tennons.

Cut the slots into the ends of the rails/aprons while they are square then cut to the required angle (30 degrees)

A wedge shaped sub-base on the rouret table will hold the leg at the correct angle to enable the mortices to be routed out.

I used a similar method on my glass table although the angle was 45 degrees and the rail joined into the corner of the leg.

Jason

 

[edmund]

Thanks Steve.

I think that rhombus or pentagonal shaped legs are a good way to go. I could use dowels or slotted tenons to make it easier to get the faces right (got my angles wrong as well - 120 and 60 only out by a factor of 2!).

 

[Sgian Dubh]

If you think about it Edmund, the only way that M&T'd (or dowelled or loose tenoned) joints will work in this non-sqauer framework is if you make them all a bit sloppy in the mortise width so that the joints will slide together. This is do-able, even on other more extremely off-square structures such as triangular frames. But it does compromise the joint and the integrity of the whole structure somewhat.

Here another couple of options you might consider.

1. Sliding dovetails where each rail has the tail at either end and they slide into a corresponding dovetail housings at the top of the leg. A bit of careful planning and rigging up with a router table will do the job (along with other options.)

2. A slip tenon cut where the mortise in the rail is extended to either its top or bottom edge which again allows you to slide each rail on individually to its matching pair of legs. Slainte.

 

[luthier49]

Here you are Edmond. Steve Maskery is correct with the shape of the legs. This table is mortice and tenon joinery and was made 1994. The legs were shaped first then turned. Sorry about the quality of the photo, I don`t have a proper scanner, so this was scanned with my document scanner instead.

 

[luthier49]

I just realized, my table is octanganal and your wanting to make hexaganal. Oh well, the principal is the same. :?

 

[edmund]

Thanks guys. Still in planning mode for this one... (Like the octagonal table btw).