Roast My Workbench Design

[Joshua Lucas]

I'm getting to the point in my workbench build where I need to stop overanalyzing everything and commit to a design. So, I'm submitting it to you all for a final sanity check.

The overall design is Moravian, with an angled leg vise and traditional tail vise.

The top is currently a single 3.5-4" slab of white oak that I am going to saw into a split top because it's too cupped to practically flatten in one piece. Splitting the top will also improve its stability because it will create two rift-sawn slabs instead of one flat-sawn one.

The leg vise chop and parallel guide will be hickory. I'm not 100% decided on the tail vise materials, but it will have at least the important structural components made out of hickory.

The long stretchers are joined to the legs with a Shitage Kama (https://hillbillydaiku.com/2015/12/15/blind-dovetail-thru-mortise-and-tenon/) joint. I have used this joint before and I feel that it is more robust and more attractive than the standard tusk tenon on the Moravian bench.

Right Quarter View
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Left Quarter View
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Front View
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Close-up of parallel guide with leg vise chop hidden. It will be an all-wood version of Will Myers' ratcheting parallel guide. Edit: obviously the ratchet isn't going to balance as rendered. There will be a spring to hold it against the parallel guide.
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Underside of tail vise. There may be a few more guide blocks in here but I'm not 100% sure where they need to go and I didn't feel like rendering them. It shouldn't be a problem to figure that out as I build it.
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I may add a narrower version of the upper stretcher/apron on the "21st Century" bench here (https://www.popularwoodworking.com/woodworking-blogs/another-21st-century-workbench/). The dog holes in my design are close enough to the front edge that they will interfere with a sliding deadman. I also feel that this design is more robust than a deadman.

[Jim Koepke]

Joshua, The only thing looking a bit off to me is the over hang for the tail vise end of the bench.

Your Shitage Kama joint seems like a great solution to making a joint for the ability to knock the bench down if needed.

Wedges are a great way to hold things:

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Clamps help when something is going to have forces working against it.

jtk

[Derek Cohen]

Hi Joshua

I agree with Jim that there is too much overhang at the tail vise. I am not sure whether a Morovian bench is intended to work with the tail vise you have chosen? Ideally, the work piece gets clamped over a leg. This is where a vertical leg scores for stability. The Morovian triangulated legs should be strong, but I imagine that they will flex more than a vertical leg when working over it.

Regards from Prague

Derek

[William Fretwell]

Joshua, over a third of your bench hangs over the leg. This will make your bench unstable and wobble in use. Moravians generally are smaller with much thinner tops. The weight ratio of top to bottom is out of balance. The wedge joint for the stretchers sacrifices a shoulder, bad idea on a bench stretcher, you need BIG shoulders and bigger stretchers.
A clamping ledge under the front of the bench helps, the split top may provide that. Your dog holes should be oblong and angled in 3 degrees.
There is a reason big benches have straight legs and big stretchers, just look at historical benches!

[ken hatch]

A good rule for bench building is pick a classic design and build it with no changes. Then work on it, if something about the design drives you to barking at the moon, change it by modding the bench or if unable to mod it build another then work on it until you either love the change or return to barking at the moon.

After working on a bench you may be surprised at your insights as to the reason for the design elements that have survived over years and many bench builds. If you make changes willy nilly you may never arrive at those insights, most design elements that have survived over the years are there for a reason and have been proved and improved over time.

I'm a fan of the Moravian style bench for the modern woodworker and his shop but it took several builds and working on it for some time before developing an understanding of the wisdom of the original builders. If I had made change to the first build I doubt I would have ever understood why the bench works and would have gone on to another style bench with most likely the same result, a less than optimum bench.

Of course YMMV,

ken

[Jim Koepke]

The wedge joint for the stretchers sacrifices a shoulder, bad idea on a bench stretcher, you need BIG shoulders and bigger stretchers.

Little bits of wisdom such as this are one of my favorite parts about reading bench build threads. The reinforcement of basic building rules helps others with their projects be they making cabinets, tables, chairs or a bench.

The individual style isn't as important as what holds it all together.

jtk

[Andrew Seemann]

It's your bench, so build it however you want. That said, there is some wisdom to staying close to traditional designs for a hand tool bench. Hand tool benches are a mature technology. Most of the details were worked out hundreds of years ago by thousands of craftsmen trying thousands of designs.

Since you asked:) here is my take. I'm not as worried about the overhang on the tail vise. It is pretty typical of what Roubo calls German benches and most here call Scandinavian/Frid/Klaus benches. No pounding takes place on the vise or behind it. The tapered legs make sense for a bench that is going to take a lot of pushing down its length, e.g. planing, as they will resist racking well. As commented above though, they aren't ideal for pounding. Since straight legs are perfectly adequate for planing, and tapered legs not ideal for pounding, why go to the extra effort and taper them?

Overall observation: You seem to have a combination of a Scandinavian bench with a leg vise. Given that the tail vise is the hard part of a Scandinavian bench and the part that scares most people away from them (not sure why, they aren't that difficult to make), why not lose the clumsy leg vise and put on a proper shoulder vise? They are much more useful for dovetailing and edge jointing and hold work more securely. You're two-thirds the way to a Scandinavian bench; just add a shoulder vise and straighten the legs. Roubos, Nicholsons, and Moravian benches are trendy now, but Scandinavian style benches were/are the choice for cabinet makers for hundreds of years. There are plans out there for both Frid's and Klaus's bench.

Disclosure: My hand tool bench is a Frid bench and I love it.

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[Will Blick]

"Roast" your design?
I applaud it !
I am impressed with your CAD skills...what program are you using?
Effective use of CAD is so helpful in perfecting a design. I keep trying to get better at it.
Sanity checks are humbling, but mandatory IMO, others see what one pair of eyes often misses.
I too immediatley thought, too much unsupported bench over the legs. Otherwise, it looks like a great build, and something u will use and take pride in for years!! Nice design!

[Joshua Lucas]

Thanks for your input, everybody!

One thing to note is that this isn't my first rodeo: this will be my second bench (not counting doors on sawhorses); the current one is similar to Chris Schwarz's $175/$280 workbench (from the red workbench book). So, I have a general idea of how I work and what I want my bench to be able to do.

My attractions to the Moravian design are twofold: one, the angled leg vise. This strikes me as the best all-around front vise design, with its huge capacity and the ability to clamp boards vertically without racking. No offense to the shoulder vise fans, but I don't think there's anything it can do that the angled leg vise can't do at least as well.

The second is the ability to knock the bench down. This won't be a portable bench by any means, but even though I don't have any plans to relocate in the near future, at my age (29) it's a near-certainty I have at least a few moves in my future. A bench that can be moved by two people is a big plus.


A lot of you are concerned about the overhang. I agree that it does look like a lot. One important thing to note though is that from a stability standpoint, the overhang isn't measured from the leg joint but from the base of the leg, which decreases the overhang by about 5 inches, from about 24 inches to 19. This is basically the same overhang used by most end vises, including the Benchcrafted wagon vise and the Frank Klausz tail vise. It's also less than a quarter of the total length (80 inches).

Also adding to the stability is that this is a very heavy version of the Moravian: my CAD software is estimating 270 pounds for the total weight. That's assuming dry wood too, which this is most certainly not!


As for the Shitage Kama joint, I'm not concerned about its strength. It's very strong and derives most of its strength not from the shoulder like a normal tenon but from the fact that it's essentially a dovetail. The wedge drives the angled bottom face of the tenon against the mortise wall and very effectively prevents racking. Here's an x-ray view of one of the joints:
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Note: as modeled here the wide part of the tenon does not actually fit through the narrow part of the mortise. I realized this today when cutting the first of these joints. It's easy to correct by just making a bigger wedge as it should have been in the first place.


Wil, thanks for believing in me, haha!

I'm using Autodesk Fusion360. The learning curve is probably pretty steep if you haven't done parametric CAD before, but it's way more powerful than SketchUp and the like. And it's free for hobbyists!

[William Fretwell]

OK Joshua lets do some simple maths. Your tenon slope, all one of them is at about 15 degrees, as you increase the angle, say to 45 degrees the longitudinal force from wedging increases; would you agree with that? You have essentially a slope and a wedge, as you continue to increase the slope, say to 90 degrees you have a through tenon with a 90 degree wedge. For the same size, the force along the stretcher is given by the Sine of the angle. The Sine of 15 degrees is 0.259, the Sine of 90 degrees is 1.

So essentially you will achieve a quarter of the longitudinal force given by a through tenon of similar dimensions. In reality it will be much worse than a traditional bench as the tenons are larger and the wedge of a through tenon can be driven far tighter.

Keep thinking: The angled wedge of a through tenon is in an angled hole, it is exactly the same thing as you are building just at 100% efficiency instead of 26%. Now if the 26% is enough for your design please let us know in a few years.

Yes the longitudinal pivot point is in line with the bottom of the leg, however the lateral wobble is in line with the top of the leg. It is the lateral wobble that bothered me when using a bench with overhang. My bench is traditional with essentially zero overhang.

Ken’s insight into appreciation by doing what many lifetimes have taught us is most profound.

I have not even touched on racking forces in a frame, shoulder size and separation. Have fun with your half a dovetail!

You did say ROAST!

[Frederick Skelly]

Josh, it's your money and time. And chances are, even if your design is all wrong - which it probably isnt - nobody will get hurt. So go for it. FYI, I built my bench out of dimensional lumber and deck screws, long before I found SMC. The bench works very well. Probably because I spent 2-3 trips to woodworking stores studying how high end benches were constructed and used a lot of that. I also built a half scale mockup before the final bench.

You might consider doing a mockup of some or all of that bench (using cheap dimensional lumber), to test your designs. Several people here have built more than one bench. For example, Ken Hatch in post #5 has built probably six or more, and IMO, he is our resident expert. He has studied them and tried different classic designs to understand their workings. His advice on a bench is worth it's weight in gold, as is that of several others who have responded.

I'm not trying to tell you to always do what our forefathers did - if that was so, we'd all be working in Parthenon-style buildings and driving ox carts to work. But there's some kernels of wisdom here.

Look forward to seeing pictures of your bench build, regardless of what design you ultimately choose.
Fred

[Jim Koepke]

My attractions to the Moravian design are twofold: one, the angled leg vise. This strikes me as the best all-around front vise design, with its huge capacity and the ability to clamp boards vertically without racking. No offense to the shoulder vise fans, but I don't think there's anything it can do that the angled leg vise can't do at least as well.

An angled leg vise can still be subject to racking. The workpiece has to pass through the centerline of the vise screw to lessen racking.

There are many ways to counter racking in various kinds of vises. In my case a stack of shims has actually made it possible to use racking to advantage, especially with holding thin work:

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Here having shims in the vise to counter racking also works to regulate the vise's pressure on the workpiece.

jtk

[Joshua Lucas]

In that comment I was contrasting the angled leg vise's vertical clamping ability to a normal leg vise more than anything. A standard leg vise can't clamp a board vertically without being subject to racking, while an angled vise can put the workpiece on the centerline of the vise and so avoid racking.

Of course any vise design can rack and the angled leg vise is no exception. It's more that some vises do so in more annoying ways than others. My current bench has a metal/wood hybrid wood face vise like I believe yours does, Jim. That vise may possibly be the worst possible design when it comes to racking since the only thing preventing it are a few little screws (six #12 wood screws on mine I think) holding the vise to the underside of the bench top. My current bench has a Douglas fir top so those little screws are now quite loose in their holes. Obviously you've made lemonade out of lemons but it's still not an arrangement I'd knowingly choose.

[Alan Schwabacher]

The dovetail wedged tenons will work fine. Paul Hasluck, Scott Landis, David Charlesworth have described them in their books, and from the name you gave them, it seems there may be an eastern tradition as well. My bench made with them decades ago is solid as a rock.

The flaw in the analysis above is that the critical force is the pull out force, not the force pulling shoulders in under no applied force. Before building my bench I tested smaller dovetail wedged tenons to destruction: the tenons do not slip. Failure is by pulling off the tenon itself. This breaks far more wood than is present holding in a tusk tenon, but I'll just say that both types appear sufficiently strong.

You are right that in terms of balance, overhang beyond the foot is critical. But rigidity of the top would be higher with less overhang. Note that many benches with large overhangs also have a 5th leg to stabilize the end.

A slanted leg vice does allow unimpeded vertical clamping, but note that it does not require the leg itself to be slanted. Slanted legs are generally used to help a lightweight bench to resist planing forces. Yours sounds heavy enough to not need this.

[William Fretwell]

My analysis compares force vectors in similar set ups. Testing the pull out force to destruction is pointless as in the real world resisting wracking is the goal, the force applied to the shoulders at rest must be greater than the wracking force when in use. With Large wide wide shoulders this is easily achieved.
The splayed legs of the Moravian design mitigate some of the wracking but two shoulders still help. If your roof caves in on a Moravian design then the pull out force may be of some interest if you seek refuge under it.

[Matt Evans]

Nice bench design.

I like the ratchet mechanism on your leg vise. I've built a few of those, been using one I made out of aluminum for the last year.

I have the lever mechanism on the same side as you, and I would HIGHLY recommend you change it to the other side. You constantly have to move a step or two when you want to use the vise, and, while this doesn't sound like a lot, it is very inconvenient and drives me nuts.

Regarding the tenon/shoulder design, I wouldn't worry about it personally. That joint is very strong, easily tightened up if it loosens a bit, and it has held up very well on several large trestle tables and other furniture I've built. If you NEED to add a shoulder to the top I have done that once or twice by modifying the the wedge and design a little and having the wedge driven into a hidden pocket on the stretcher.

[ken hatch]

I have one question about the ratchet on the Parallel Guide. Why bother? BenchCrafted's crisscross has been perfected, it is an easier install and works a treat, better than any parallel guide with or without a ratchet mechanism.

Forgive an OF's ramblings but there is a point that I will get to. Back in the Dark Ages I flew two different aircraft that were designed and built by two of the legends of aviation. One was Bill Lear, when Lear needed to find a solution to a problem he would find the simplest possible. As an example he developed the "jet pump" for moving fuel. That simplicity made the LearJet a joy to fly, it worked with you and felt as if it was a part of you. It was my favorite aircraft to fly. The other was Ed Swearingen, unlike Lear he would find the most complex way to build something. The SA227 was a pilot's nightmare with nicknames like the "Texas Death Tube, San Antonio Sewer Pipe, Necroliner and so on. The Merlin/Metro was always working against you and was miserable to fly.

There is a reason for the above, if possible follow KISS. There is a reason thing evolved the way they have.

ken

[Jim Matthews]

I don't think clamping should be the primary concern of bench design. Proper height, stability and flexibility are more important.

So long as the top is sturdy, boring the occasional hole to accept holdfasts will accomplish most tasks.

*The more things I make, the less I tend to clamp them down, particularly when planing.*

It is VERY rare that I hold a thinner piece of stock upright in my tail vise. This position duplicates the function of the (more versatile) leg vise.

The movable tail vise on my bench is frequently jammed due to Seasonal movement. I did not build the bench and would not include the feature, as it offers little utility and is difficult to make. Your all wooden design would be more sensitive to changes in humidity.

An alternative exists - which would be simpler to mount.

https://store.woodandshop.com/product/wagon-vise-for-portable-moravian-workbench/

[ken hatch]

I don't think clamping should be the primary concern of bench design. Proper height, stability and flexibility are more important.

So long as the top is sturdy, boring the occasional hole to accept holdfasts will accomplish most tasks.

*The more things I make, the less I tend to clamp them down, particularly when planing.*

It is VERY rare that I hold a thinner piece of stock upright in my tail vise. This position duplicates the function of the (more versatile) leg vise.

The movable tail vise on my bench is frequently jammed due to Seasonal movement. I did not build the bench and would not include the feature, as it offers little utility and is difficult to make. Your all wooden design would be more sensitive to changes in humidity.

An alternative exists - which would be simpler to mount.

https://store.woodandshop.com/product/wagon-vise-for-portable-moravian-workbench/

Jim,

I'm with you on the tail/wagon vise and work holding in general. I often think I should have a standard reply on tail vise posts, do a search on Jim's work holding posts. For me an even better option than Will's vise for the few times I need one is just, I forget what Veritas calls 'em but I think", their Wonder Dog. That said, I have Will's wagon vise on a shelf waiting for the next bench build just to give it a go so I maybe I will know what I'm talking about.

BTW, that procedure worked out with BC's crisscross. I believed I'd never find anything better than a wood screw and a parallel guide until I built a bench with the crisscross.

ken

[Joshua Lucas]

Ken, I seriously considered the Crisscross 14 but even with the smaller size I couldn't find a way to get it between the screw and the through tenon that I was happy with. Either I would have to raise the screw or put the stretchers just a couple inches off the ground. In the end I decided to go with the ratchet design, which has the advantage of greater clamping pressure and variable toe-in for tapered workpieces. Worst case, if I decide I hate it I can retrofit it with Jim Ritter's chain guide.

[Prashun Patel]

I didn't read all the responses, so apologies if these are already addressed.

FWIW, I have a very similar bench. My learning:

1) Angled legs can interfere with the tail vise's ability to hold things vertically, say when working on the end of a tenon. Consider making those legs vertical or moving them farther from the plane of the tail vise opening.

2) Dog holes over the leg or over a stretcher are a pain; they limit the use of hold fasts and fill with shavings too frequently.

3) I often wish my tail vise was flush with the left side of the bench so that I might be able to use it to saw parts. Even though I am right handed; i would appreciate this option.

4) I wish the handle of my leg vise were higher. I used to think I wanted the screw lower to allow bigger jaw capacity. I have never needed that (at least never on a part that couldn't navigate around the screw). Rather, having the screw as high as possible improves the holding power of the vise near the top of the jaws and also makes the handle more ergonomic to use (i.e. less stooping). These things are important during repeated use. You might think that a manual parallel guide requires stooping anyway, but in practice, you won't have to move the parallel guide that often. Your parts tend to be similar thickness on a given project. And each setting will work over a surprisingly wide range of thicknesses anyway.

Angle legs are sexy, and my 60" bench is remarkably stable because of them. But unless you are doing a lot of heavy thicknessing sessions, the stability may not be worth the mild inconveniences. YMMV

[Alan Schwabacher]

Testing the pull out force to destruction is pointless as in the real world resisting wracking is the goal, the force applied to the shoulders at rest must be greater than the wracking force when in use.

I don't think we disagree. The role of the shoulders is to convert wracking force into pull out force. My point is just that a through dovetailed tenon is not substandard. The component of the force provided by the dovetail tenon is sufficient to hold shoulders in contact.

Part of that may be that a shallow wedge can exert a phenomenal amount of force along the leg without damage, so that even the small perpendicular component of that is plenty to hold the shoulders tight. It may be a smaller fraction than with a differently oriented wedge, but overall it's a large force. If you leave the shoulders loose and apply a substantial wracking force, then tap in the wedge, you can see the shoulders move into contact and the joint becomes square and solid. (Square because I'm talking about square joints here.)

[Joe Tilson]

Just keep us updated on how things go. New ideas most always take a thrashing at first.
It's your idea, and I wish you the best with it.
Nothing against the notes from some very knowledgeable people here. The next thing you know we all may have one similar to it
Like Jim Kirk said to Scotty; young minds, fresh ideas.
Best wishes,
Joe

[ken hatch]

Ken, I seriously considered the Crisscross 14 but even with the smaller size I couldn't find a way to get it between the screw and the through tenon that I was happy with. Either I would have to raise the screw or put the stretchers just a couple inches off the ground. In the end I decided to go with the ratchet design, which has the advantage of greater clamping pressure and variable toe-in for tapered workpieces. Worst case, if I decide I hate it I can retrofit it with Jim Ritter's chain guide.

Joshua,

If you use the BC Classic screw you only need ~16" between the top of the bottom stretcher and the bottom of the slab. I've been a fan of Lake Erie wood screws but the BC Classic and crisscross is a perfect combination with much better holding power than any wood screw/parallel guide I've used. I doubt I will ever build another bench with a wood screw or parallel guide.

As always it is your bench, have fun building it and putting it to use. I hope it turns out to be a Lear instead of a Merlin.

ken

[DannyC White]

Same here with respect to the overhang. Not sure if this is your first bench, but say for example with chisel work, you want an absolutely solid bench to pound into. I have a very solid traditional bench but I can tell the difference with the piece placed directly over a supporting leg versus placing the piece just on the bench surface but not exactly over a leg. This is only a slight difference, but I would imagine any overhang like that would not be efficient for chisel work.

Totally agree with other posts, go with what has been proven before by hand tool workers before electricity was even discovered. It's like trying to improve on the design of a violin.

On the design side, the bench looks like a Telsa truck, Vulcan-like. Personally I prefer to add some curves, spice it up, give the legs more form.

But in the end, it's your bench, enjoy it.

[Tom Bender]

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Hi Joshua
A couple thoughts on the stretchers;

This view shows that the short stretcher will interfere with the long stretcher, or be glued in with a short tenon. But with angled legs it is the short stretcher that sees the greatest stress.

KD design compromises strength vs 100% glued joints. And moving this bench with a hand truck will be easy, much easier than say a piano. And those are moved all the time.

Sweeping under your bench will be inconvenient.

If you raise the long stretchers a few inches they will clear the short ones and your broom.

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My stretchers are 3" x 5" and tucked right up to and slightly recessed into the 3" top. Absolutely rock solid.