Crisscross Leg Vise Problem


Recommended Posts

Hello Gentlemen,

I am building my own version of the "Crosscross" leg vise.

I have it constructed, an it is in operation, but when the jaws grab,...and I keep turning the screw, the bottom of the leg keeps moving forward. This of course causes an angle at the jaw faces...and I am assuming also reduced clamping pressure.

 

In my research this can be caused by tolerance between the screw and nut...tolerance or gaps between legs and grooves, etc....

But I have made sure everything is perfect. (at least as perfect as I can get it)

 

It seems to be violating all logic, and I cannot tell where the movement it coming from.

 

Has anyone had this same problem with this type of vise, and found a root cause and solution?

I am sure there is more than one cause....but would love to hear of any experience in this particular problem, to help me find the root cause of mine....

 

Thanks!!

Link to post
Share on other sites

What you are describing is why I think that the crisscross variant of a leg vise was a solution in search of a problem. It’s possible to get the crisscross mechanism to behave, but that’s a bit of a feat of engineering.

 

I have a standard parallel guide and a pin for my leg vise. I set it up so that the pin end will be at least as wide, and probably a bit wider than the board that I want to clamp. This way, if there is any angle, it’s so that the top of the leg vise chop is tilted towards the board, which increases clamping pressure. And you can get effective clamping with a number of different thicknesses of wood. I can easily clamp boards between 1/2” and 1-1/4” in my leg vise without moving the pin.

 

If you’ve ever used a wooden screw clamp, you’ll know how useful that property can be. In fact, a leg vise can be thought of as a wooden screw clamp set on its back with the jaws pointing up in the air.

 

I don’t want to sound discouraging, and I’m sure you’ve already put a lot of time and effort into your design. Even so, I would consider getting rid of the crisscross mechanism and installing a parallel guide instead.

Link to post
Share on other sites

I just finished my bench build a few weeks ago and I installed the Benchcrafted Crisscross.  I don't have this problem but I know the Benchcrafted version is installed so that the top of the chop contacts while leaving a gap at the bottom on the chop (they call it toe in).  I'm not sure if that feature helps with this problem, but I figured I'd mention it.

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Who's Online   1 Member, 0 Anonymous, 119 Guests (See full list)

  • Forum Statistics

    29113
    Total Topics
    393946
    Total Posts
  • Member Statistics

    21954
    Total Members
    1529
    Most Online
    Dave M
    Newest Member
    Dave M
    Joined