Roubo Question

[Maurice Ungaro]

In Chris Schwarz's blog, he documents a bench class he thought in Germany. Of note, the leg tenons that fit into the top are the single type called for in his first bench book. I thought it odd, since he was all in favor of the authentic Roubo dovetail/double tenon treatment. Anyone else notice that? Any comments as to one treatment over the other (beside the single tenon being easier and quicker in execution).
http://www.popularwoodworking.com/wo...er-a-workbench

[Gabe Shackle]

I believe it was for speed. In his blog he describes some crazy, chainsaw-like mortising machine that could chomp out the mortises in a few minutes per bench. They also used an enormous circular saw to square the ends of the bench that was from the same manufacturer. I assume when you have to build out 8-10 benches in a work week you get to take a few shortcuts in the hand-tool only categories.

[Tony Shea]

Is def for the sake of speed. In reality, this connection between the top and the base is probably the most important part of the joinery. It is what ties it all together especially when you have no top stretcher on any side or end. Therefore the strongest and probably most recommended joint would be the tenon/dovetail joint. But the one shown during this other class will def work, especially if wedged.

[Tim Null]

I just finished my own Roubo bench. I contemplated the tenon/dovetail joint, but decided against it. I had read other builds, I think Benchcrafted, that talked about the strength of just the tenon. I did a non-through tenon and then placed a horizontal stretcher on the short sides. This is where the leg vice is and on the opposite end as well to account for any compression forces. After putting it all together, this bench is a rock. No racking, or anything. The dovetail joint is really cool looking and is very strong, but it may be overkill. I am not worried about my bench at all as far as strength goes. There is no break in the top with a through tenon, but a wedged one would be more than sufficient in my opinion.

Just my experience.

[Jessica Pierce-LaRose]

Chris kind of just answered to this in his latest blog entry at Lost Art Press

I’m repeating it here, five years later, because anytime I teach a workbench class I get asked by readers why I’ve changed my philosophy of constructing workbenches. Why have I abandoned the sliding dovetail joint? Eschewed the wooden spindle? Flushed my thoughts about using pine?

Truth is, I haven’t abandoned or changed a thing about what makes a good bench. Make it solid. Use the best joints you can. Use the cheapest material that is the stiffest and heaviest. Make it as long as your space will allow.

The rest is noise.

He continues to address the sliding dovetails and such.

Honestly, my little bench, I never even got around to attaching the top to the legs permanently. I was too busy having fun using it. Someday soon I'll get around to it, but if with a hefty top and beefy legs, it lets me do what I need. It's so much better than every excuse I've been using for a bench, that's for sure.

[Randy Bonella]

I followed Chris' book and did the single tenon. My bench is big and heavy. Doug Fir 24x80x4 top and 6" sq legs. I can move it by myself but just barely. takes all I got to push it around.

The single tenon seems to work just fine. Before I pinned the top to the legs I was using the bench and it was rock solid. no racking or movement of any kind. The tenon dovetail would have had added a cool factor and more authenticity to an already amazing piece of equipment but after taking a year of on again off again work time to get it finished I went for the most expedient path, single tenon. Besides I was worried enough about making 4 good square holes and adding two large dovetails seemed a bit much at the time. If I ever do this again I'll most likely implement the sliding dovetail joint.

[Derek Cohen]

As Randy notes, there is more than enough stability and rigidity coming from a blind mortice and tenon, especially if this is beefed up by draw boring. That is how I did mine.

I would argue that there is a point in which the construction becomes overkill. Deciding where this point lies is the question. The dovetail is a good idea for lighter, thinner-topped benches. My top is 3 1/2" of European Oak (as in the recent CS blog), and weights in at over 220 lbs (100 kg) without any hardware. The base is Jarrah, with wide/broad sections that do not twist or rack, and weighs the same. In other words, decent weight and fitting joints will determine rigidity and stability, rather than the ultimate M&T joint, per se.

Regards from Perth

Derek