This is a Moxon-style vise, whipped up out of a couple of bits of 6x2" treated pine, a bit of decking timber, and some bar clamps. I suppose it would be nice to be able to make it out of nicer timber, but this stuff is perfectly serviceable.
Some day, hopefully, I'll be able to sort out a pair of hand-screws to provide the clamping force instead of the bar clamps. The clamps do a decent job, but they're more awkward to manipulate.
A Moxon vise is excellent for furniture making, as there's no obstruction to the work piece in the middle of the vise, allowing it to accommodate quite long bits of timber vertically for dovetailing and the like. Also, because the front face is more or less free-floating, it can clamp as evenly on tapered stock as on straight, and there's no risk of racking the jaws. This one has a gap between the clamp bars of about 600mm, which is quite a lot for my purposes.
This is a portable version, and it's just attached to the bench by a pair of clamps on tabs extending out the ends of the rear jaw. I'd normally mount the clamps with the handles downward, to keep them out of the way, but it is easier to mount them as shown here. If need be, I guess I could use a pair of long carriage bolts with hand-screws, for the lowest-profile attachment: it would be easy enough to arrange, since it's unlikely to be mounted anywhere but where it is right now.
The back jaw has a sturdy brace out the back to resist force pushing against the vise; it's probably not necessary, but it makes me feel happier.
Coupla Days Later...
The woodwork of the vise is essentially complete, and I've given all the non-meeting faces a few coats of shellac.
The photo demonstrates how it holds a tapered work piece; this would be about its limit in that respect while it's being held together with clamps. A proper screw system could probably manage a little more.
The threaded rods, when I get around to mounting them, need to be able to move a bit laterally to enable this tapered-thing-holding, but not vertically, so that they hold the jaws in the right position relative to each others' top edges. I have some ideas about how that might be able to be managed.
I think the holes in the wooden jaws through which the screws pass will need some sort of bushing, as otherwise the screws will chew the crap out of them.