leg vice construction

Re: leg vice construction *LINK*

Bill Houghton, Sebastopol, CA

>The Workbench Book has some drawings and pics on construction.

How to make the screw: some people like wood. Several suppliers have steel screws that are perfectly usable; see the link below for Lee Valley's. The nut visible in the picture goes behind the rear jaw; the collar fastens to the front (movable) jaw.

Search the archives for multiple threads on the subject.


Lee Valley's leg vise screw

ebay also

Jack Guzman from Maine

>Those screws(not LV ,but that style)are fairly commmon and inexpensive on ebay.---Jack

Some limited additional information

Bill Houghton, Sebastopol, CA

>I've picked up at garage sales a couple of screws designed specifically for leg vises. The difference from the Lee Valley example is that the collar (at the handle end) has an oval hole, and the "T" into which the handle goes, and the collar, are curved ("T" convex, collar concave). This allows for the fact that a leg vise movable jaw is not always dead parallel to the fixed one.

My grandfather's leg vise (made by my uncle) doesn't have a collar, and it's necessary to pull the jaw back - although the jaw always caught on the threads enough to ride back by itself - another way of dealing with the issue. Since I had to bend down to set the pin in the bar at the bottom for jaw opening, it was never a big deal. Post-retirement, when I rework my bench, I'm going to reinstall it - I've missed it, and my experiments with other types of vises have confirmed that it's the right vise design for me.

One note if you're buying from eBay: make SURE that you get a screw with a nut, and confirm with the seller that the nut's in good shape. The forms and pitches of the threads on these screws may not be infinite, but the variety is sure greater than the commonly available modern thread forms/pitches.

Any reason why.... *LINK*

Steve Kubien

>...I couldn't use this Lee Valley shoulder vise screw? I realize that it is 5" shorter than the tail vise screw but otherwise, I think it would work (removing the fitting at the end of the screw, of course). The reason I ask is that I have 2 of these kicking around in the shop from my old shoulder vise and sliding bench dog/tail vise (no longer in use).

Thanks,

Steve Kubien


http://www.leevalley.com/wood/page.aspx?c=1&p=31134&cat=1,41659

Re: Any reason why....

Bill Houghton, Sebastopol, CA

>The catalog description says, "7-1/4" clamping capacity (less wooden shoulder thickness)...", which implies that is roughly the length of the threaded portion. You've got at least 2 inches, and three or four is better, of thickness for each of the two jaws. If you recess the nut in the back jaw so that the threads are right at the face of the rear jaw, and used a 3" thick movable jaw, you'd have, if I understand the description right, 4-1/4" of clamping capacity - not much.

Plus, no collar at the handle end.

Still, if they're free...the reality is that most vises are only ever open a little anyway, and if your use of a leg vise were chair parts, boards being planed, etc., the limited opening wouldn't matter. So, as always, your use of the tool is the dominant issue.

It's worth mocking up. I would lay the screw out with an imaginary front and rear jaw and see how it works out. If you do decide to use these, put a big, thick washer under the handle "T," to keep the wood from getting chewed up. My grandfather's leg vise uses a brass washer of almost fender-washer proportions, and about 3/16" thick.

One nice thing about leg vises is that they're so simple. No careful fitting of parts to slide against each other, as with a European tail vise, no getting the chain synchronized on your LV twin screw vise, no building the shoulder vise into the bench so it doesn't rip off the first time you grunt down on the handle. Just build your two jaws (the rear jaw is often a leg when building it into a bench, so you've already built that one), drill the needed holes, cut your mortises for the strut at the bottom, drill holes in the strut (use a strong hardwood - maple, oak), find a suitably sized pin (my grandfather's uses a large nail, about a 60d spike), and Bob's your uncle. If you were sufficiently fueled up and had the wood already, you could probably build one in an afternoon.

It also doesn't need exotic wood - my g.f.'s was built of Douglas fir, undoubtedly all he could afford in the Depression when he built it.

One comment, which I've made before: the major weakness of my g.f.'s vise is that he fastened the top of his bench on top of the legs using large wood screws only. As the holes wore, and as the vise operated against the top, it all loosened up, so that by the time I inherited it, I couldn't clamp in the top 1-1/2" of the jaw - the top would move backward. I wound up having to be sure the wood being worked was at least three inches wide, so it could be clamped between the leg and vise jaw. Even if you're building your vise to be flush with the top of the bench, notch out the top so that the rear (non-moving) jaw comes all the way up to the same level as the front (moving) jaw.

Another, though speculative, comment: The Workbench Book shows some pictures of leg vises that slant sideways, so that the clamping area is not directly above the screw. It doesn't take much slant to accomplish this, and it appears to have the advantage that you can clamp pieces vertically and still get plenty of firmness. When I rebuild the leg vise on my bench, using my g.f.'s old vise screw, I plan to build it this way.

Thanks Bill

Steve Kubien

>I'll mock it up sometime this week. The legs of my bench are flush with the front edge of the top so, indeed, I only need to make one jaw. I think I can maximize the clamping capacity by leaving the nut close to the surface of the bench leg. That way, the only loss is in the thickness of the jaw I make. I'll probably use a piece of construction grade 2x material since I've got some kicking around. Do you think that is thick enough? I might be able to find a piece of oak or maple and I will definately take your advice on the washer.

Let me know your thoughts,

Steve Kubien

Give it a shot

Bill Houghton, Sebastopol, CA

>I picked up a leg vise at a garage sale - never used that looked like a clear grade 2x6 jaw, so a con grade 2x4 is worth a try, as long as it's not one of those with a giant knot midway in the board.

PARENTAL ADVISORY: THE FOLLOWING DISCUSSION DOES NOT USE PROPER ENGINEERING TERMS, BECAUSE I NEVER TOOK ANY OF THOSE COURSES AND COULDN'T HANDLE THE MATH ANYWAY.

Part of the issue is how long the lever is between the clamping point and the screw - if it's too long, you'll probably get too much flex. Leg vise jaws flex a bit as you tighten up, but you want the flex to be reasonable.

In the long run, I think you'd probably want a hardwood jaw, but if you've got the 2x4, I'd knock it together and try it out.

For experimenting purposes, and possibly forever, just a hardware store washer, if your hardware store carries washers that size, should be enough under the handle.

I'll keep you posted. Thanks

Steve Kubien

>

Ditto

Doug Littlejohn

>I was able to get both the screw and off bench piece of the vise for about $25 shipped off of Ebay. All I have to do is to mate it up to the lower rod like piece and it'll be good to go.

Sherwood