Maybe a dumb questions? Engineering vs pure mass for workbench (Paulk vs Roubo)

[Curt Putnam]

Stan, thanks for that excellent analysis although I don't buy it entirely. For example, how often does one load in material that clearly off-center so as to weaken the joint? Not arguing, just raising an eyebrow. Ok. not wanting to beat an irrelevant baby, what is your opinion of: a split top bench (don't argue about the split top) with leg vise on left (I'm a righty) with one housed tenon (square, round, or rectangular) and an exposed rectangular chunk of leg. Since it is a split top the housed tenon would have to be part of the transverse bearer upon which the top sits.

I like the exposed tenon idea because less than perfectly executed mortises and/or their tenons would probably result in a weaker bench than my "proposal" (I'm quite sure that no one has done a formal study of the various loadings and likelihoods of resisting damage.) Twin tenons at the other corners make sense although a 1" square spline across the transverse bearer would totally stop movement in the long dimension and a couple wedges would stop it the other way. I might even have to spring for the Benchcrafted plans to see how they do it.

[Stanley Covington]

Stan, thanks for that excellent analysis although I don't buy it entirely. For example, how often does one load in material that clearly off-center so as to weaken the joint? Not arguing, just raising an eyebrow. Ok. not wanting to beat an irrelevant baby, what is your opinion of: a split top bench (don't argue about the split top) with leg vise on left (I'm a righty) with one housed tenon (square, round, or rectangular) and an exposed rectangular chunk of leg. Since it is a split top the housed tenon would have to be part of the transverse bearer upon which the top sits.

I like the exposed tenon idea because less than perfectly executed mortises and/or their tenons would probably result in a weaker bench than my "proposal" (I'm quite sure that no one has done a formal study of the various loadings and likelihoods of resisting damage.) Twin tenons at the other corners make sense although a 1" square spline across the transverse bearer would totally stop movement in the long dimension and a couple wedges would stop it the other way. I might even have to spring for the Benchcrafted plans to see how they do it.

Curt:

I clamp material off-center in my leg vise frequently. For instance, when cutting a tenon at the end of a stick, the leg vise screw gets in the way of clamping the stick both plumb and centered. Or, when cutting dovetails in a drawer side, the screw gets in the way again, and clamping it off-center is the only option. Same situation occurs when using the leg vise to hold a wide board for edge planing.

Any of these scenarios will cause eccentric loading at the vise. If the stick, for instance is clamped on the right side of the vise jaws, it may bear only on the edge of the benchtop and not on the exposed dovetail tenon. The force of the screw will cause a reaction force to the right of the screw, which will cause the screw to bend. This is obvious. So what does that bending force do to the the leg? And what resists that bending force, Curt? Obviously, it is the wood between the dovetail tenon and the vise jaw combined with the wood between the rectangular tenon and the dovetail tenon that must resist the tendency of this force to twist and tear the leg through the edge of the benchtop. A continuous edge at the benchtop is obviously stronger than one severed to accommodate a decorative dovetail tenon.

Of course, so long as one does not get carried away with the torque applied to the vise screw, and the benchtop's edge is strong, straight-grained, and without much runout, the rearward tenon will probably be strong enough to resist these forces without popping off the left side of the benchtop edge. But the simple fact is that the exposed dovetail tenon, especially at the vise, is not an improvement, but a decoration.

I understand why the exposed tenon at the vise face is attractive. I felt the same way until I sat down and designed my last workbench with my first leg vise and looked at the forces in play. My reading of other's experiences led me to realize the actual danger of popping off the benchtop's edge. The problems with the "steps" at the benchtop's edge, and the difficulties they cause with clamping, are both obvious and something others have warned me of. An exposed tenon is not an improvement IMO.

Sorry, but I don't follow how you plan to use splines and wedges. Nor do I understand your proposed design. By "transverse bearer" do you mean the spreader, or beam, rigidly connecting front and back legs?

If so, and assuming the tenons would penetrate completely through the benchtop, the mortise and tenon joints would be located below the split bench, and would not be cut into the tenons penetrating the benchtop. This will weaken the leg's tenons a bit, but if you size your spreader tenons right, and the legs are made of a strong wood with straight grain and are big enough, it should not be a problem.

I am not fond of split tops. They handicap a workbench used to plane wide panels. Fine for working narrow pieces of wood, I grant you. In any case, I will defer a discussion of the structural details to those that have made and used them.

Do you plan to glue the leg tenons to the benchtop, or leave them dry so they can be disassembled for moving?

Stan

[Matt Lau]

Thanks for the tips...particularly, thanks Stan!

This post is particularly to avoid doing things in a half-way, haphazard manner.
My particular challenges will include:
1. Must not move when being used--no racking or twisting during use.
2. Must be moveable-- my workshop/garage is pretty small. It'll be helpful to move this workbench down a bit
Sometime down the road, I may want to make some cabinets.
3. Must have a vise-- I've tried going viseless ala crochet, but found a vise to be immensely helpful for small parts (like neck billet, bridge work, etc).
Thankfully, I have an old Record Quick release that I can bolt to the future bench.
(as in many things, you were right stan)
4. Hopefully not ugly?


Anyways, I'd love to run some more ideas past you'all:
1. Use the laminate maple for the top. Have a few dog holes
2. Have some beefy truss braces to avoid racking
3. Have a big piece of plywood on the floor with a mortise to set the legs into.
4. Maybe some wheels that flip under bench, ala Schwartz http://www.popularwoodworking.com/wo...r-bench-mobile

Anyways, I've been thinking a lot about stuff like dust collection, tooling, etc.
I'd like to pattern my workshop some operatory rooms that I've seen in the past:
1. most crap easy to reach, but out of the way..
2. The area clean, sterile, uncluttered.
3. Tools readily organized for quick deployment.
4. Bigger, heavier tools moved out of the way until used: bandsaw, planer, table saw, etc.
5. The workbench being the "operating table" with an auxiliary workbench for tool holding.

It probably won't be the best place for a few dudes to pull out a beer, but it'll allow work to be done in a efficient, safe, comfortable manner.
(Since alcohol + sharps + untrained dudes = bad idea, that might not be a bad thing.)

[Curt Putnam]

Stan, once again, a hearty thank you!

Transverse bearer = 4 x 4 or 4 x 6 connecting two legs (same end) at the top and upon which the 4" top rests. A spline could rest in dados in the transverse beam and the top. A couple wedges on either side of the spline would stop all movement except in the up direction. That's about as far as I've gone in thinking about connections.

I think I need to order Bencrafted's plans before I go much further. I do have the wood. Several hundred feet of curly soft maple that I got at a killer price.

I am well aware that benches get built a certain way because that way has worked well over the centuries. What the split top will do me: Each 12" half will something I can handle by myself. Each half will fit through my planer if need be. The space in the middle gives my saw a place to go (too arthritic to use a saw bench) Then there is tool storage and a planning stop. Since it will be a walkaround bench, on Rockler's bench casters, I can use each half for different projects or different phases of the same project.

Matt, my apologies for the detour I've caused in this thread.

Thanks, Curt

[Stanley Covington]

Stan, once again, a hearty thank you!

Transverse bearer = 4 x 4 or 4 x 6 connecting two legs (same end) at the top and upon which the 4" top rests. A spline could rest in dados in the transverse beam and the top. A couple wedges on either side of the spline would stop all movement except in the up direction. That's about as far as I've gone in thinking about connections.

I think I need to order Bencrafted's plans before I go much further. I do have the wood. Several hundred feet of curly soft maple that I got at a killer price.

I am well aware that benches get built a certain way because that way has worked well over the centuries. What the split top will do me: Each 12" half will something I can handle by myself. Each half will fit through my planer if need be. The space in the middle gives my saw a place to go (too arthritic to use a saw bench) Then there is tool storage and a planning stop. Since it will be a walkaround bench, on Rockler's bench casters, I can use each half for different projects or different phases of the same project.

Matt, my apologies for the detour I've caused in this thread.

Thanks, Curt

Thanks for the clarification, Curt.

Your reasons for the split top are indeed sound.

Stan

[Curt Putnam]

Reviewed what I could on Benchcrafted's site. Ordered plans. Appears as though BC uses a pair of square, rectangular tenons off the leg. Have to read the plans but it seems as though their transverse bearer is not as major a player as I'd envisioned. Once again, I want to thank you for your excellent exposition of the leg vise / leg /top connection. I think you may have saved me from a major faux paux. Take care.

[David Dalzell]

I don't know how common this is, but I have a decent/heavy workbench that I have augmented with 4 ea 25 lb bags of #8 lead shot. I put one bag in each corner of the lower support members. So I have added 100 lbs to the bench weight; this takes up no additional storage room and does not interfere with any work/storage that I need. This does wonders for stability and eliminates movement when planing or doing any other hand work.

[john zulu]

I am going to receive a lot of hate mentioning this idea..... Here goes.

Top solid hardwood. 3" to 4" thickness.
Legs welded metal...... 1/4 thickness tubing. Weight can be increased by placing sand into the tubes.

I would build this if one intends to change the bench over time..... But in pure fairness, I would rather build a solid roubo bench any day. Sourcing material for that bench can be difficult as
one needs to hunt proper wood stock for it.

[peter Joseph]

I think a standard Roubo fits all of your requirements. I have a massive one in my 9 x 10 ft shop that sits against the wall. A local sawyer advertised KD 12/4 white oak for 3$/bf at the time I was drawing up the plans so that is what it is made of. The top is 28" by 7ft, 4.5 inches thick. Legs are 6x6. Shop floor is oak so I can slide it if I need to but the need seems to arise very sparingly.
PJS

[Scott DelPorte]

Hi Matt,
Let me suggest that if you primarily are going to build instruments, that your needs may be slightly different than those of someone primarily working on furniture. My experience is with acoustic guitars, so it may be different for solid body guitars, but most of the guys I know aren't using a typical woodworking bench with leg or tail vises etc. as their primary work surface. For instance much of the planing you do on an acoustic guitar involves boards that are 20 to 30 inches long, but really thin (<1/8" thick), and have to be clamped to a flat surface rather than be held in a vise. And the work you do in a vise often involves smaller or irregularly shaped pieces that dont always fit well in a regular woodworking bench vise. I ended up with a large (60x60) laminated maple top mounted on a storage cabinet with generous overhangs all around the top. There is one regular woodworking vise mounted on one of the four corners. I have large overhangs to make it easy to clamp stuff to the bench top, and that is the primary way I hold wood for planing. I also use a parrot vise mounted on surface that is bolted to the wall for irregular or small parts. My main bench is heavy enough that it doesn't move, but I have seen people use lighter tables successfully for planing by connecting one side to a wall, and relying on the wall to keep the top from moving. It works well, but makes it more difficult to move your bench around.

If I had your bench top, and wanted to use it as my main bench for guitar building, I might consider mounting it on legs so I could still clamp to as much of the underside as possible, and fix one of the smaller sides to the wall so I could plane toward the wall without it moving around. I would probably try to figure out a way to mount a regular woodworking vise to it while leaving plenty of room to clamp things to the underside of the top.

Thats just my suggestions. Lots of more experienced people on the forum. You can also look around at the pictures of guitar builders workshops on their websites and get some other ideas. I hope this is helpful.
Thanks
Scott

[Matt Lau]

Scott,

Thanks for the post! You nailed it. I think it's sort of hard for non-luthiers to understand the more delicate, fragile nature of the craft of acoustic guitars.
In terms of your workbench, a few questions:
1. Why 60" x 60"? I have short stubby arms, so I have a hard time reaching past 22"
2. Ever try holdfasts? I became a convert after getting a pair of Grammercy's on a blum bench.
3. If you get a chance, please look at kiyond's videos on youtube. He's a Japanese luthier with a rather different approach than the western workbench.
Granted, it seems like a specialized planing beam on a traditional workbench. https://www.google.com/search?q=japa...LU27FbkJZjM%3A

[Scott DelPorte]

Hi Matt
I watched the video, and he uses his workbench in much the same manner as you could do with your bench top. He mounts it to a regular workbench so he can clamp underneath it, and you could do the same (if you had a bench) or just fix one end to a wall. He uses a bench stop thats built into the top sort of like bench dogs, and then clamps the really thin stuff. On my bench, I will clamp thin scrap boards to the top, and use them in a similar manner to the stops he uses. A wide board used as a bench dog seems to support the work better for me. That works pretty well for me for things like fingerboards or bridge blanks. I know one guy who has built hundreds of instruments, who keeps a 1/8 inch aluminum plate that he clamps to his top to use as bench stops for thin stock. And then with really thin parts like tops/backs/sides, I clamp one end with 2 big C clamps, and have to flip the board around and measure with calipers a lot to get an even thickness. If you were clever with hole placement, I imagine you could do the same with holdfasts, but I haven't tried it. One thing worth noting is you really need a good deal of clamping pressure to hold the wood for planing. You may want to plane in the direction of the grain, and also scrub across the grain, so it has to be held tight enough to resist forces in both directions and not crush the wood. Finally, for planing tiny parts like saddles and nuts or rosette tiles, I have specialized jigs that get clamped in the vise. All the tiny pieces of the rosette in my profile picture were shaped and held in little jigs and dimensioned with a block plane.

The 60X60 is a fairly new bench (about 3 years old) for me, and may have been in response to having worked so long on tiny cramped benches. I like the large surface area, because there is enough room to leave something in the assembly stage while working on parts, and I like the large overhangs because I rely on clamping to the underside so much. Some people have a different assembly table and a workbench, I sort of have it combined. In use, I never reach across it, its more like I am working on a few different things along the four sides of it. It takes up a good deal of real estate in the shop, but it suits how I work. There are a bunch of other guitar builders here too that might have other good suggestions for you. Lots of different ways to skin the cat, and if you build for a long time you will probably adapt your setup a few times along the way to suit how you like to work.
Thanks
Scott

[Matt Lau]

Thanks!

I'm assuming that you're a pretty tall/big dude.
Ironically, all the guitar builders around my area use a thickness sander (Michi Matsuda, Ervin Somogyi, Lewis Santer, Randy Angella, Leo Beundia).
They just look at me funny when I mention that I just want to use planes!

Anyways, I'm still in my prepubescent phase as a neander.
There's always something new that seems to be less messy, less fussy, more "right" that I've found people have done before!

Mind posting a picture of your workbench/fixtures sometime?

On the planing front, I started with Grizzly indian planes (horrible-> LV bevel up Jack, small smoother (excellent) --> Mujingfang (rough, but tune up nice and take a ton of abuse --> Japanese (still need to tune up other planes, really appreciate the attention to detail). Do you have a particular favorite? I know a guy in SF that almost does everything with one homemade Krenov frankenplane with two slots for his blade--one place for thicknessing, one place for dimensioning the fretboard, one place for scraping, one place for jointing...all in one plane.

[Megan Fitzpatrick]

Just a note on the breakage on Chris' cherry Roubo...that slab glue-up was _really_ punky and had a split there (filled with black epoxy). His original SYP one and the oak one he uses now, and my eastern white pine Roubo, remain solid as a rock (OK...my EWP one is a quite light-weight rock; I pile heavy stuff on its shelf to keep it from walking across the floor when I use a jack plane).

[Scott DelPorte]

After building for many years using just hand tools, I spoiled myself and got a drum sander for thicknessing. It is quicker, but by no means necessary, especially when you are starting out. I save a couple hours per guitar, but I dont make nearly enough guitars to justify saying I need it. Its more of a luxury for a hobbyist like myself. Some of the luthiers you mention are really well known professionals who can probably more easily justify the cost. I usually taper parts of the soundboard a little, so I have to plane it by hand anyway after I get it close with the sander. I have also used a drill press "safety" planer to hog off wood before final thicknessing with a hand plane as a way to save time. I might take a board from 1/4 inch to 1/8 inch and do the rest with hand tools. It saves a little time, but I have never felt great around those "safety" planers.

For guitar making, I do 90% of the planing with a LN 4.5 smoother and a LV low angle block plane. I have other planes that I use for certain things, but for the most part I could get by with just those two. Key thing is get good at sharpening, and spend time setting up your planes well. One builder I know does pretty much everything with an old #4 Stanley and a low angle block plane, but his old plane is well set up and he keeps the iron sharp. I always end up needing a low angle block plane for end grain, otherwise I could probably do it all the planing a smoother. You really dont need a lot of tools to build guitars other than lots of clamps. There a hundreds of specialty tools in the StewMac catalog, and it sort of gives a false sense that you need lots of special tools for every procedure. Its not really true, and it sometimes add confusion. Here is a picture of my bench with a bunch of walnut on it that is now in the shape of a table. You can sort of see the size of the overhang on it. A lot of professional luthiers I know also will give classes in guitar building. If you have the funds for that, its a good way to get started.

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