Mounting vices to a torsion box table

[Frank Stutzman]

I'm building my mondo workbench/assembly table. I'm using torsion box design for the bench top and am currently trying to figure out how I am going to mount my vices. These are the vices I'm currently looking at:

now my bench top is 4.25 inches thick. What I am concerned about is how deep the 'back' of the vice is. In other words, if I mount the vice to the underside of the bench top, will the top of the vice be flush with the bench top? Can anybody point me to some drawings with dimentions for such a vice?

[Australopithecus scobis]

Make your wooden faceplate(s) as tall as necessary to reach the top of the table. The iron doesn't have to go all the way up.

[Mike Richardson]

The link says they are 3"deep?

[tom]

It's usually best to have your hardware in hand before hacking up the bench. If you can find a copy of The Workbench Book, there's a lot of good info there to be read. Do you think a torsion box will be strong enough to mount a vise upon? Tom

[George]

Sure - fill in the web in that area with solid wood.

[Frank Stutzman]

Well, one of the features I want in a vice is a pop-up bench dog. If the vice is shorter than the thickness of the vice, it would make the bench dog less functional.

[Frank Stutzman]

I read that to say that the jaws are 3" deep. The mounting surface would be something over 3" from the top of the vice. The question is how much more?

[Frank Stutzman]

Probably true.

Yes. I plan on filling the web where the vice will go with a soild block of wood. Maybe even some of the surrounding webs.

[mike hide]

why build a torsion box if the design does not have any torsion loads ???

[Frank Stutzman]

Uhmmm, I'm no mechanical engineer, but where did I say that there wasn't going to be any torsion loads? There may or may not be. This bench is going to be used for a lot of things.

However, the reason I'm going with this design is because I need this table big (4 ft by 16 ft) and free standing. It also needs to be exceedingly flat and as level as possible. A torsion box design seemed to be the most economical way of accomplishing all this.

Sigh. Ya just gotta love usenet. Ask a question and get a half a dozen questions back that are only tangentially related. Could someone just take a tape measure to their vice and tell me the dimention I need?

[George]

Ya gotta just love some of the questions. The answer, already given, is the same answer as any other "how big" in woodworking. Make it fit. That's what the sport is about.

Sure helps when you have the iron at hand and available for a couple of test runs so you don't put wood in the way of stabilizer bars and such, BTW.

Be sure and have blocks in the web for your dogs before you laminate the skins.

[Australopithecus scobis]

Good point. Consider, though, that you could put a couple of holes in your face plate for removable dogs. I don't like the metal dogs in vises; too harsh for the wood, but ymmv.

What are you doing about dog holes in the middle of the bench? I can't readily visualize how one would do that with a torsion box.

[Frank Stutzman]

Thanks, thats an item I hadn't thought of.

More solid blocks filling in the webs. My webs are 5.5 inches square. I'll fill in every other (maybe every third) web in with a solid block that I will drill for dogs.

[Australopithecus scobis]

Whoops, you answered that same question a couple of posts after the one I replied to, sorry.

I wonder what happens inside a torsion box. In my complete and utter ignorance it seems you'd want to nail/screw your blocks dead center: one nail per vertical face, through the center of the web segment. Engineers: what's OP's best method to attach these blocks? Would pressure on a dog cause the block to rotate in place, munging up the thin web?

[CW]

Glue solidly top, bottom and to the webs. You'd want to make it as much like a solid piece as possible.

[Frank Stutzman]

Well, I did what I should have done first -- called somebody and had them take a tape measure to one.

The folks at the nearest place that might have one (Rockler in Portland,

200 miles away) were very tolerant of my inane question. The 9 inch Pony vice they had on hand would fit a bench up to 2 1/2 inches thick. My design is currently 4 1/4 and I'd like to make it 4 1/2. I'm going to have to think about how I'm going to do this a bit more.

[Leuf]

Well here's another one :) A freestanding bench with vises and dog holes wants to be as heavy as possible. 3 sheets of MDF ripped in half will get you 2-1/4" thick with no less work getting it flat and a lot less work getting it put together. Inlay some hardwood where the dog holes will go and you're done. 4 sheets gets you 3". Mine is only 2'x4' 3 layers and it laughs at anything that tries to move it.

-Leuf

[Leuf]

Oops, I was thinking your bench was 2' by 16'.. double my numbers on quantity of sheets. Okay maybe you're on the right track ;) Maybe even half the bench torsion box, half solid might work.

-Leuf