Another Bench Question

[Jim Koepke]

Not wanting to hi jack the thread Graham Wilson started on Roubo Benchs, here is a new one. One of the replies to the thread includes:


the over hang is 12" on each ends and 26" inbetween the legs(5" legs).

I am curious about different thoughts on the overhang.

Sometimes having a leg at the edge of the vise is convenient for clamping work to the leg and in the vise. Of course, a leg vise has this feature built in.

It also seems too much over hang could contribute to racking.

jim

[Eric Brown]

Jim I have the Noden Adjust-a-Bench legs and have some overhang on both ends. The adjustable height and overhang makes it nice to sit down sometimes for detail work. Never had any problems with racking either.

Eric

[jamie shard]

I made a schwartz-style "english bench" with the leg vice and aprons. I really like the zero overhang of this model. Essential for the "how do you plane the edge of a door" type operation: just hold the front edge in leg vice and clamp down the far end with a clamp against the apron.

If I was to modify the design at all, I would have everything still in the same plane, but I would have the apron start about 4" below the bottom of the top. Board shorter than 4" can be planed on the top of the bench, longer boards would reach the apron. And with the gap, it would be easy to reach underneath and push up the veritas circular dogs (pups) that I used. That's the main downside of zero overhang and aprons.

Hope that helps!

[Rob Fisher]

Jim,

In Schwarz's book, the over hang on his Roubo is 15" from the outside face of the leg (both ends are the same), with an overall bench length of 96". Just as a reference.

IMO the ability of the bench to resist racking has more to do with the method of construction (in Schwarz's case he uses drawbored M&T's and fairly substantial members), than the overhang of the top. If the top were to overhang too far it would droop. This certainly could affect the rigidity of the bench, but again it goes back to the joinery used. I am guessing that there is a practical limit to the overhang (cantilever), dictated by materials used, type of construction/joinery, thickness of top and a bunch of other things that I am sure I am forgetting at the moment.

I have not yet built my own workbench but I am in the process of planning one, so please take my words for what they are worth. As a side note I have recently read Schwarz's book, which I am constantly referencing/reviewing as I plan my bench. I highly recommend it.

Rob

[Jim Koepke]

Hope that helps!

It not only helps, it gives me ideas, dangerous thing those ideas.:D

Maybe instead of racking another description would be better, that is lift off of the tail end when planing long boards. My current bench is only five feet long. When planing a long board away from the tail end, the tail end would lift. That is why there is now a bucket full of cement resting on the tail end foot board.

jim

[John Sanford]

The flip side is, depending on how you build your bench, overhang gives you more clamping options on the end of the bench. It's easier to sleeve something over the end, etc.

I don't think a solid wood top is going to present any sagging problem with even 2' of overhang. I had 18" of overhang in my top, which was a 1.75" thick "solid" core (actually, compacted sawdust) door. It was fine until a friend of mine stood on the unsupported end while installing an overhead light. I know that a "roubou" (i.e., 3"+ thick) solid wood wouldn't have budged.

Me, I'm a firm believer in both END overhang, and NO aprons. Deep clamping with aprons is a PITA. Kinda like clamping something to a factory drill press table.

[David Gendron]

My bench is only 5 feet long but it is fairly heavy( all DF construction) and never experience any lifting of the end wile planing... Or standing on the end and I'm 230lbs!!

[Jim Koepke]

My bench is only 5 feet long but it is fairly heavy( all DF construction) and never experience any lifting of the end wile planing... Or standing on the end and I'm 230lbs!!

Well I got you beat by about 10 pounds, and I have been trying to shed a few more.

Also, sometimes boards of 8 feet are edge planed. Eventually, a longer bench will be built, but there are a lot of other things ahead of it project wise, and still have to decide on a few of the things that will be going into its make up.

All the input on this question is appreciated.

jim

[David Gendron]

My next bench will also be longer, at least 8 feet. I have a bigger shop now, it's 12x12!

[Dave Anderson NH]

Jim, My bench is not a Roubo, but it has no racking problems. The bench is 90" long and the undercarriage is 54" long and made from 4 x 4 stock. At one end there is a 24" overhang with an Emmert K-1 vise (85 lb) suspended from the over hang. The other end has an overhang of 12". With a top of ash 3.25" thick there is no problem of droop on either overhang. I love the extra clamping options the overhangs offer.

[Jim Koepke]

The end opposite the tail on my bench, (is that the nose end?), has a skirt that often gets a board clamped to it for a planing stop. The edges have a piece that is a little deeper than the main part of the bench that is easy to clamp on either vertically or horizontally.

I have also taken the pin out of the end of a pair of Irwin F-style clamps that can be fed through the dog holes for clamping. This was done before buying a pair of hold fasts.

The idea that Jamie mentioned about having a rail to rest wide boards on for edge planing sounds like a good innovation. I am trying to think of a way it can be rotated out of the way or work like a drawer to accommodate other options.

Versatility in all things is my goal.

By the time that round tuit comes along for me to build a bench, it will have been thought about, dreamed about and head scratched about.

jim

[jamie shard]

How about a sliding, but lockable deadman instead of a rail. More moving parts (-) but versatile (+).

[Jim Koepke]

How about a sliding, but lockable deadman instead of a rail. More moving parts (-) but versatile (+).

Or both, thinking about dados that would take an insert.

jim