Mounting the top for a new workbench

Question

I am planning a new workbench and have a bit of a dilemma. While many home shops I have seen on youtube videos utilize the garage (think of all those displaced, cold cars), I have seized our home's basement. I am retired now and intend to use this new roubo style bench for many years, but someday it will need to be moved upstairs and out. The problem is that the 4" hard maple top reaches towards 200 lbs. and the legs etc push another 75 lbs +/-. I thought it might be a good idea to have the legs be detachable. On the other hand, I want this bench to be a monolith for hand planing & etc.

My question then is would an unglued mortise and tenon table top mount be sturdy enough. I could supplement this with some lag bolts through the leg top supports. There is a lot of info on the web regarding how to design them, but not a lot of feedback on how benches performed over time. If you have a sturdy workbench how is the top mounted and how has it handled heavy handwork?

Answer 1

A workbench top doesn't actually need to be fixed to the legs or leg assembly. As Andy Rae shows in his book Choosing & Using Hand Tools the top can simply sit on round-nosed dowels that project from each leg frame:

At the opposite end of the spectrum you can use something that few woodworkers would conscience in a 'proper' job because they're so utilitarian but they work perfectly well, steel corner brackets:

Even the smallest type shown are likely good enough as long as enough of them are fitted, they are placed suitably for the worktop type (to allow for any seasonal movement) and appropriate screws are used, but if you prefer you can use the larger four-screw or six-screw versions.

Answer 2

In Paul Sellers' blog he describes Building a Workbench which uses a drop-in wedge to make it possible to separate worktop from legs for transportation

^{image by permission from paulsellers.com. Paul Sellers - How to Build a Workbench – Apron Recesses (part11)}

This sort of wedge is self-tightening and produces a very rigid and stable workbench.

On my benches I don’t rely only on the housing dado. I want something that locks and continues to lock the legs into the apron housings and never turns lose. I also want my bench to be disassembled for moving from time to time. A wedged housing dado resolves the issues.

Answer 3

There are more elaborate answers to be sure but tusk and tenon and rising dovetail joinery would lend very well to such a design. I found a perfect image of what I was thinking.

^{Image from villagecarpenter.blogspot.ca}

Tusk and tenons are known for both their strength, when done well of course, and ease of assembly and disassembly.

Now this won't do much for how the legs are connected to the top but the above image also shows rising dovetails. Weight of the top should keep it in place and the risers should allow for disassembly again. Should be able to take that apart several times and still join it back together snugly.

Shouldn't need lag bolts if you do something like the above.