No leg vise but a sliding "leg" vise

[Rusty Quinn]

Got the idea that boring a 2 5/8" hole and a mortise immediately behind (for the nut) has to weaken somewhat the left front leg on a Roubo-style bench. Never have seen a bench with an unviolated leg and a sliding "leg" vise only. What would be wrong with that from a design standpoint?

[Jessica Pierce-LaRose]

You don't need to mortise the nut, all it really gets you is a cleaner look, and a little more capacity for the leg vise. I clamp things in the vise large enough to require the extra length rarely enough that I don't mind kludging something together with clamps.

If you're concerned about the strength of the leg, make it bigger.

The number of ancient benches with some variation of leg vise seems to exceed the number with sliding leg vises considerably. I've certainly never heard of anyone having catastrophic leg failure.

In the end of course, if the sliding leg vise better suits the work you do, then by all means, go for it. But if the leg is sufficiently stout, I'm not sure it's something to worry about too much. Certainly, I'd rather have the vise applying pressure against the heavy leg, than trying to pull itself out of the groove in the top of the bench. Making the sliding leg vise assembly stout enough seems like it'd be a hassle to work around dogholes if you like them fairly close to the edge of the bench.

[Andrae Covington]

I have both the typical stationary leg vise through the left leg, and a sliding leg vise. As Joshua says, you don't have to mortise the nut. Mine is mortised about an inch and otherwise hangs off the back of the leg like a big wart.

It never hurts to increase the size of the leg if you're concerned about the through bore. As a very rough guideline, consider that building codes typically limit holes through studs in bearing walls to <= 40% of the width, with the edge of the hole at least 5/8" from the edge. As an alternative, you can drill holes up to 60% if you double up the studs. 40% of 5 1/2" (2x6 nominal) is a hole just about 2 1/4" in diameter. But surely your legs would be at least doubled up 2x6's, so 60% would allow over 3". The legs on my workbench are about 5" wide by 6" deep, with a 2-1/8" bore for the 2" screw. Solid as a rock.

I use the sliding leg vise a lot, but also the stationary, and both together. I think you could just have the sliding vise, but if you're only going to have one, the stationary in the left leg is less likely to get in your way for other operations. I move the sliding one off to the far right when I'm not using it. If that's still in the way, I unscrew the screw/chop and set it aside. Not that big of a deal, but, can be annoying going back and forth.

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[Jim Ritter]

I store tools under my bench so having the screw and parallel beam sticking in under the bench was a deal breaker. I thought about it, but just decided to add I a leg vise on the right leg also. It has a slightly shorter screw so if it is in the way it's no big deal to remove it.

http://i1135.photobucket.com/albums/m628/boatman53/workbench/th_45cd4768.jpg (http://s1135.photobucket.com/albums/m628/boatman53/workbench/?action=view&current=45cd4768.jpg)

[Rusty Quinn]

Very helpful answers. Thanks, guys!