I was reading a post by Partickhosey showing a joint he made and the associated comments regarding its strength and durability.
The joint looked like one I could try, if only to work out how to make it.
I started off with some rubbish timber jointed it square and set to work
Its obviously a half lap joint so I cut them in with the table saw
With that done marked out where the four tenons would fit.
Returned to the table saw and cut the four entry points in
This is what they look like finished.
I did some finishing sanding and fitted them together, they all fitted up OK so I started on the four tenons.
Cutting them in presented no problems at all.
So I fitted everything together.
Oh not so good very sloppy work.
Dismantling them I was about to huck them in the bin and go do something constructive when I took a look at the tenons and noticed that they had a taper down to the points.
Ah ha I thought the Tenoning Jig is out, so I checked it, sure enough it was not set at exaclty 90 deg, and along with the saw blade it was out as well.
Note: should have done this check first !!
Adjusted everything to their correct positions and cut the tenons off and tried again.
This time the result was almost the same but no taper this time.
So it was off with the tenons again and reset the jig a fraction.
I made the third tenon cut and fitted them up again.
This time a better result was achieved but was not as good as I could do so chopped off No 3 and went again.
Some more fine tuning could be done but I was running out of timber.
That was enough to satisfy my curiosity about the joint
Will it work, I beleive it will, there must have been a use for it in furniture making even if adding four reinforcing wedges to the base and sides for added strength.
Its a bit short for a table now so I am not sure if I would even bother to glue it up and destroy it just to find out the answer as to how strong it is.
I certainly agree you have a mixture of edge and end grain to contend with leading to a “weaker” joint
Table saw, Tenoning Jig and some sandpaper, however there is no reason it could not be cut with just a tenon saw.
And thats how you shorten timber using a Tenoning Jig!!
Update Feb 2016:
Some interesting information I found.
This joint is called an Interlocking Tenon Joint, its heritage from what I have found is from Japan.
A series of Time life Books
The Art of Woodworking series
Handbook of Joinery
and within there is a section Japanese Jionery from page 136 to 139.
You may find a complete downloadable PDF version of the publication On woodtools.nov.ru.
-- Regards Robert