Saturday, 25 February 2012

Defining My Vice Design...

In the previous post, I discussed a vice I saw listed in next month's Live Free or Die auction that is administered by Martin J. Donnelly Antique Tools.

Before I get into discussing my design for this vice/vise, let me first point out that "vice" is the English spelling, while "vise" is the American spelling. I try to use English spelling whenever a difference comes along as, while I'm Canadian, this country was part of the English Commonwealth from it's inception through to 1982. Many of us here still tend to acknowledge our British roots wherever possible.

The renderings that I included in my previous post were just for general dimensions. While I stated in the article that accompanied them that I was thinking of having the lower screw come at things from the back of the vice, the renderings included do not reflect this.

Damien left a comment regarding my concept and felt that having the screw come at things from the rear wouldn't work as it would not keep the legs parallel. Damien has offered me his opinions a few times in the past and I tend to listen to him. Having followed his blog, Woodlooking, I have come to believe he has a far better grasp of physics than I. With respect to his knowledge, I have created this second post about this vice to explain my vision of it further, hoping Damien will return and give me the yah or nay for it. I would hate to cut up that beautiful piece of maple sitting here, only to find out it won't work.

The following render is a cut-away view of how I would like to deal with the screws...

The render shows both the screws trapped to the front upright. The main screw is trapped as it passes through the face, done so using a collar and recess so the screw is still allowed to turn freely. The second, lower screw is also trapped to the front upright in the same manner. This one, though, is trapped where it butts up against it, rather than passing through it. Both screws use female thread blocks attached to the rear upright, both centre pinned on each side to allow them to rotate vertically.

While Damien was concerned with the two uprights not remaining parallel to each other, that is exactly what I am looking for and the sole reason this vice caught my eye. I do not know if Arthur's version has a non-parallel capability, but hopefully mine will. As I want to do self-standing carvings and make odd-shaped boxes, I think having this feature on my vice would be ideal.

Note that the render shows a hole above the lower screw and below the upper. These are labeled "Pivot Capture" and are there to accept a wood pin that would pass through to them from the edge of the rear upright. Being able to fix the pivots vertically will overcome having to deal with a "sloppy" front upright when the unparalleled feature isn't necessary. I would assume that I would probably work the vice with the upper pin installed and the lower removed most of the time, as this would limit having to adjust both screws every time I use it.

I may be still all wet, but hopefully, I'm only just damp.



1 comment:

  1. This is very creative, but (looking from the safe shore :) I see some problems. As the pivoting screw is off center, the screw will be strained. The pivot can be set in line with the screw, but then it still needs to be very strong. I would try to follow the original design with a screw capture set on the side combined with enough vertical space to allow tilting the jaws.
    For the lower screw I think two rotation points are needed to make the whole work. Removing the pivot and letting the screw end in a small vertical recess (without a top and bottom screw capture) may solve the problem. I would probably use a more standard slide with many pinholes. The extra advantage is that a slide helps more to keep the jaws from tilting sideways when a workpiece is set off centre.