A leg vise question-

[Dave Zellers]

I'm in the process of building what I'm calling my tiny workbench. It's only 48" long by 18" wide. But it's a stout laddie! I found some rough sawn oak boards at my favorite lumber yard and MAN are they heavy! Don't know why and don't care. The weight will be a huge asset to this tiny workbench. But to the point-

I have decided to put not one, but two vises on this bench. The first will be the large Veritas Front Vise -- http://www.leevalley.com/us/Wood/pag...9,41661&ap=1-- (Which I'll attach to the end. HA!) and the second will be a homemade leg vise on the opposite end (but the front!) using this screw-- https://www.amazon.com/dp/B01M2109GD...Q0XU3LSD&psc=0

But still, I digress. My question is, why do all the leg vises I see taper from the top to the bottom? Is it because they are tapering down to the width of the leg they are attached to?

I'm thinking of making that leg wider than the others and not tapering the moving face of the vise which would provide more clamping area all the way down. Seems logical to me, but even without a wider leg to work from, I'm scratching my head over why anyone would taper the bottom of the front piece of a leg vise except for style.

Just curious re any leg visers thoughts.

[Brent VanFossen]

I can't answer for the others, but I use the Benchcrafted hardware for mine with the Crisscross support. This is rigged specifically with a degree or two of toe-in to make sure the vise chop contacts first at the top. I also have suede leather attached to both the chop and the mating area of the top side of the bench to give better gripping, but it also adds local thickness. There is a small gap at the bottom which gives no clamping there. So having a wider vise chop would not give me any more clamping area.

I think they're mainly tapered for aesthetics. I can assure you, though, that the gripping power of the vise is amazing, and I don't find that I need more contact area.

[Charles Wiggins]

I don't have any direct experience with leg vices but it seems that the relief cuts down the sides would serve two main purposes.
1) To reduce the weight of the chop. The more weight, the more effort it takes on your part to screw the chop in or out, and the more wear on the bench screw. The extra weight of leaving the lower part of the chop full width is not really going to give you extra clamping force. Any piece of 8/4 hardwood that is 3"-4" wide is more than adequate to withstand the clamping stress. The actual question should be, "Why does the chop flair out at the top?" The answer being, "The additional contact between the chop and the workpiece provides more grip to prevent slipping."
2) Less wood in the way of your knees if you need to get in close to the bench.

If you want a heavier bench to keep it from moving around I would look for other places to add weight - thicker top, beefier legs, on-board toolcase, a lower shelf with blocks, etc.

[Dave Zellers]

I think they're mainly tapered for aesthetics. I can assure you, though, that the gripping power of the vise is amazing, and I don't find that I need more contact area.

That is my thinking as well, but as yet I don't have any real world experience.

Sincere thanks for your real world experience.

I imagine it is also related to the pin board (?) at the bottom. The more (tighter) the options available, the closer you get to equal clamping pressure. But I agree, a properly done leg vise would probably be strong enough for most applications.

I still think I will not taper because in this case I can easily make the leg vise leg wider during construction and I will explore alterations to the pin board for finer settings. Shims can also make up any difference.

I actually have no clue what I'm talking about since not only have I never even clamped anything in a leg vise, I've never even been in the same building with one.

But I've been You Tubing up a storm.

[David Eisenhauer]

Real men taper. Hey, I don't make the rules, just keeping the fire going.

[Prashun Patel]

I don't think the taper is for aesthetics. I have a leg vise and here's my experience:

The chop is heavy. Tapering is a way to relieve some weight on the screw or the guide. I clamp plenty of table legs, and long panels in the leg vise - using the top area only. Having clamping force way down isn't so critical - you really only need it close to the point you are working (racking issues notwithstanding).

More critical than the taper is the height of the screw and the relative height of the parallel guide. In my experience, you want that screw as high as possible and that guide as low as possible. This does several things:
1) Creates the greatest fulcrum length and therefore the maximum clamping force near the screw
2) Puts the screw closest to the working surface of your clamped piece, which maximizes the clamping force
3) Minimizes the user having to bend over to loosen and tighten the screw. These vises can otherwise become fatiguing.

As for the guide being low to the floor (mine is a set of shims actually resting ON the floor), even with a manual guide, I find that I rarely have to adjust it at all. It's set to about 1" thick, which is fine for things as thin as 1/4" and can even handle a 2" table leg. My point is, you have to stoop to adjust a very low (manual) guide, but you don't have to do it that often, and it provides better force near the screw than a higher, more ergonomic guide.

[Dave Zellers]

Everything said makes sense. Plus, I want to be manly. I'll probably taper the bottom now partly to reduce weight and partly since you want the clamping pressure near the top.

Man there are a lot of different approaches out there- trapping the pin board between wheels, using a chain and sprocket to keep the chop vertical, the X- hardware, wedges, and today I ran across a sliding leg vise.

Technically, I guess that's not a leg vise. I'll just keep it simple but I might do the wheels above and below the pin board.

Thanks for the input!

[Christopher Charles]

Hello Dave,

I’m curious about why you are interested in both as front vise and leg vise since they have similar functionality? I’m also interested in what kind of work you plan as that would help with advice. Pardon the pun.

best
c

[Dave Zellers]

Hello Dave,

I’m curious about why you are interested in both as front vise and leg vise since they have similar functionality? I’m also interested in what kind of work you plan as that would help with advice. Pardon the pun.

best
c

The Veritas front vise (which I'm putting on the end) Will have jaws the full width of the bench- 18". With dog holes on the moving jaw and the bench top, I'll use it to pinch flat work on the top for whatever needs doing- sanding, scraping, carving, routing, etc. Also hand cut dovetails and regular vise things.

The leg vise is for edge work on larger pieces like cabinet sides or just boards that could be held by the leg vise on the left and supported by the other leg on the right. Also just for fun because I want one and the only thing I needed to buy was the screw.

I have just retired from life as a custom finish carpenter that included a lot of cabinetry.

It's time to have some fun. I'm getting ready to re-do our kitchen and then who knows? Whatever strikes my fancy.

[Derek Cohen]

Dave, I think you are on the right track in using a leg vise for edge work. That is its forte.

As I recall, the screw is recommended to be between 9" - 12" from the top.

From the screw up, the chop needs to be wide enough to hold wide boards. From the screw down, there is no clamping (other than the sides of a large panel), and width can be reduced. It just needs to be wide enough to secure the screw and the parallel guide. Any reduction in width is otherwise aesthetic ....



The parallel (or leg) guide I have is solid (no holes) as it is adjusted via a chain (AYS chain adjuster). This allows for variable widths without the need to set a distance.

You might also want to consider adding a sliding deadman, which is very handy when clamping panels and doors ...





Regards from Perth

Derek

[Dave Zellers]

Thanks Derek- that info re screw position helps. I just came across your review of the AYS chain system yesterday!