Knockdown Roubo Bench Construction Details

With the recent upgrade of the knock down Roubo workbench, there have been requests to learn more about the construction details used.  There are many ways to build a bench, so here was the criteria I needed in this one:

  1. The primary purpose was and is to display our line of tools, and provide a work space for their demonstration.  It needed good work holding ability, and stability was important.  This also meant it had to have enough weight to keep it in place regardless of the type of floor it was setting on.
  2. It needed to be portable enough to fit into a car, along with all the other items traveling along to the shows.
  3.  It needed to be attractive and also have traditional workbench appearance and function.

The Roubo style of bench is my favorite.  My original bench is in this style and has been serving my needs very well.  I was familiar with the construction techniques and felt it would be a simple job to carry this into the knock down bench.

To a large degree, the wood determined the size of the bench.  I had two Honey Locust beams, one 12″ x 12″, and the other 6″ x 12″, both 8′ long, cut into 3″ thick planks.  The top is made of one 12″ and one 6″ plank glued together to make an 18″ wide top.  Leg lengths were cut off these planks so it finished out at a little over 5′ long.

The legs are about 5 1/2″ x 3″, and are as small as I would want to go. Stretchers are resawn, and are about 5 1/2″ x 1 3/8″.  Having a tall stretcher is more is more important than width to prevent wracking.

The bench breaks down into five basic components, plus the shelf.  There are two leg assemblies which consist of one front and one back leg plus stretchers.  One assembly also includes the leg vice.  These each have a top stretcher to add rigidity and allow for securing the top in place.  This top stretcher is not as tall to allow for lag screws to pass through into the top. (I used Spax brand screws.)  The front leg is mortised into the top with 1″ tall x 1″ thick.  I wanted something substantial because the leg vise is exerting pressure against the top and needed to be solid.  Interestingly, I have found that there is no need to screw the top in place; it stays put just with the tenons.

Bench with top removed. Note holes for lag screws.

Tenon on front of leg.

The stretchers are assembled with draw bored pins;  two per tenon on the lower stretcher and one for each top  stretcher.  These were made of white oak.

Stretcher with draw bored pins. Also note the bolt hole counter bored for a 3/8″ bolt.

The long stretchers are assembled with short tenons and bed bolts, purchased from Lee Valley tools.  I modified the bolts by tapping a hole in the end and inserting a machine screw to serve as a handle when assembling.  The holes in the legs are counter bored and also are offset to the inside of the stretchers.  That way. the hole for the barrel nut did not go through the stretcher, and it looks nicer.  However, I did glue a block to the inside of the stretchers to add material since the hole is so close to the edge.  These blocks also serve the purpose of supporting the shelf.

Stretcher joint showing the offset hole and added block on the stretcher.

Assembled leg joint. Note the machine screw that serves as a handle on the barrel nut when assembling the joint.

When I added the Acer-Fererous screw and Benchcrafted criss cross, I could no longer use the bed bolt in the vice leg.  I am going to try it without it and see how it does.  This may need to be rectified in some way in the future, but we will see. Also, the nut was screwed to the leg using two lag screws.

Nut mounted to the back of the vice leg.

All in all, this bench has worked out very well.  I also use it for demonstrations and find it can be used for vigorous work without any trouble.  The top is the heaviest part, and probably weights somewhere around 60 to 70 lbs, which is manageable.  And it is very compact and fast to set up.  I am quite pleased.

Disassembled leg assemblies and stretchers.

 

 

4 Responses to Knockdown Roubo Bench Construction Details

  1. Thanks Dan for the information on the knock down Roubo bench. I’ve made several benches and I now need one for demonstrations that provides a solid leg vise. Admittedly, I’ll have to work on getting the vise assessories. I can’t get over how smooth the wooden vise screw works on your bench. I have an antique wooden vise screw on another stationary bench and it’s tough operating it. I really appreciate it.

  2. Schechter says:

    Fascinating. Haven’t decided whether to use a leg vice if I go with construction of this kind, as I don’t do the same kind of work as you do. (Much of what I’ve done till now has been canes, but future projects will involve boxes of varying but mostly small size, & specialized shelving.)

    • I think you would find the leg vice to be very versatile because it has a good amount of clamping depth, and pieces can be clamped vertically with minimal racking due to the fact that the work piece is right next to the screw.

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