Hi, Frank S, & Gramps43,

Lo and behold - didn't I say in my reply to Gramps43 previously, that somebody somewhere is bound to have come up with a vise design like this, and there Frank has found one right away on EXACTLY this principle - the Heinrich Vise - designed and patented way back in 1943 ! Very interesting indeed.

He used 2 rods for locating the sliding jaw and one as the 'pusher'. When talking about making a larger version with twin rods, I assume you mean like this, as distinct from twin 'pusher' rods which wouldn't be necessary as any off-centre clamping forces are taken by the jaw sliding rods in the case of the Heinrich vise (or the moving jaw tenon in the slot in the base as on my conventional design). I briefly considered dovetail location at the outset but opted for the easier to make basic tenon idea in the end.

In the distant past when working in and around machine shops, I have come across the vises you refer to with the buttress thread and the half nut although have never actually used one myself. The threads would have had to be kept well clear of swarf, otherwise the not fully engaged thread would have a tendency to jump out of engagement ? They were all large vises (6"+), which makes me wonder if it would be viable to make a small, say 3" vise on this principle - then again why not ?

Here's another interesting alternative which I have just discovered on YouTube - definitely worth a look :-



Thanks for reply Frank & Dennis and you're both very welcome to the club of 'never ending planned projects' of which I am a lifetime member !

p.s:- Dennis, could you tell me where on YouTube you saw the vise similar to mine ?