Tennon design?

[Edward Clarke]

I'm building a Roubo bench (who isn't?) right now and am nearing the point where I need to cut the tennons on the top of each leg. These legs are presently 5 1/2 inches square solid pine. I haven't been able to find any references on the design of tennons. In the original Schwarz book these tennons would be simple - 5 1/2 long, 1 3/4 wide and the depth of the bench top ( four inches in my case).

Would it make a stronger joint to add two additional cuts to the tennon making it 4 1/2 long and 1 3/4 wide? This would give me a half inch lip on each side of the tennon in the length wise direction of the bench. Are there any old text books that go into this kind of design detail?

Is this a waste of time? The stretchers will be made of 16/4 ash and the top is also 16/4 ash. Both will be drawbored to the tennons. My skill at this time is not up to making the traditional tennon and dovetail joint.

[Chris Friesen]

I wouldn't worry about making more shoulders, it's not necessary. I and think you're selling yourself short...you can almost certainly do the original joint, it's easier than it looks. See http://www.badaxetoolworks.com/craft...workbench.html

Incidentally, as long as it's reasonably close it'll be fine mechanically. This is a workbench, not fine furniture.