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Leg vices... musings

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condeesteso

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I admit I am fascinated by benches. Recently did a big one with a wooden-screw twin-screw face vice, but I really wanted to explore leg vices. So I have just done one and want to share what I discovered, what I tried and how it came out.
First though, I am not the first to make one and this isn't about sucking eggs... but for anyone considering one, some of what I tried and learnt may be handy.

The basic principle. It's a vertical beam with the screw nearer the top, and a guide through the leg at the bottom. So closing force is down-geared (the ratio of distance between guide pin and screw, over the distance from guide pin to jaw). In my case it was about 75%. But it's worth noting a vice is pressure, not force. And a typical leg vice has a jaw a mere 8" wide. There's good reason for that I think, as they are quite prone to racking (in the horizontal plane) so greater width would be fairly useless.

I made mine using a metal screw (recovered from an old Axminster bench tail vice. It's very basic, and was lying around.
Wood v metal screws - wood ones cost way more, have a much greater pitch (about double) which is good, but stick out a lot more and tend to get in the way sometimes. Also note the beam / gearing principle - the metal screw has a lower pitch but that pitch is up-geared in that beam ratio. I mean one turn may be say 10mm, but at the jaws it's maybe 13mm.

My whole reference to leg vices has come from Chris Schwarz (who seems to me to be the World's foremost advocate of them). So I read all his work on them (not just the book, various mag articles too). Then I decided to make a few changes:

- it seems usual to place the guide very low down. That means raising the stretchers a bit, probably. I placed the guide above the stretchers (which are 125mm, 100 off ground). This has an effect on that beam ratio, but given the quite sm,all area of the vice face I did my rough sums and decided a few benefits: I get the stretchers where I want them, I don't bend so far to move the guide pin (sad, I know) and I can get my foot under the bottom of the beam to pull it out when opening the vice. NOW it's only leg-vice users that may get the real advantage of that one :)

All the support in this vice is in one vertical plane - so it is sure to rack side-to-side. I made the guide mortice interference, and spent a pretty time tuning it so it was zero clearance side-to-side. It does need a few mill top and bottom though, as it will effectively pivot.
 

condeesteso

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sorry that ended high n dry... upload or lose it and start again!
So, the hole through leg was zero clearance too - 28mm. The screw kind of cut it's own thread first time - but nil sideways slack, a good thing I felt.
The beam has a beech face at 90 degrees, so the grain strength is in the direction you would want in a vice. And it's screwed on so replaceable (good plan Bugbear!)
Anyway, I really like the design principle. Simple, shop-made, cheap (metal screw does very well I reckon), and lifetime serviceable. It looks like this:
b4-1.jpg

b4-2.jpg

b4-3.jpg


Will report back once it is in proper use... any niggles, tweaks etc.

p.s. yes. a new spinny stick thing for the vice is planned, that one is pretty nasty.
 

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jumps

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you have been busy!

I thought your 'shop was full of some oak right now? Look forward to having a closer look at this vice arrangement next week - will email tomorrow.
 

condeesteso

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Hi Jumps - no, the oak (400kg of it... I'll come back to that :wink: ) is sitting on the drive!!
Get on over and test this bench, get your banksia nuts and help me shift some oak. Said I'd come back to it.
 

condeesteso

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Nails - not yer furniture grade stuff. Green structural, brick base built already, an Edwardian sun loggia complete with period stained glass, slate roof etc... just can't face moving the oak nearer the workshop and need to do it before spring kicks off. If it starts to dry much the whole thing will fast become an exercise in curves.
 

jimi43

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I like this a lot Douglas!

I need to see this next week! I can come over and supervise the oak moving if you need anyone to shout "left a bit....right a bit...." :mrgreen:

Jim
 

cambournepete

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Interesting stuff.

condeesteso":2x97qyup said:
sorry that ended high n dry... upload or lose it and start again!
Bitter experience on forums and company systems has taught me to to do the typing in a text editor on my local machine so I don't lose my carefully crafted words of wisdom!
 

Paul Chapman

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condeesteso":2hjeetc0 said:
I admit I am fascinated by benches. Recently did a big one with a wooden-screw twin-screw face vice, but I really wanted to explore leg vices.
Hi Douglas,

I share your fascination with benches and have really enjoyed your various bench threads. However, I am puzzled by the recent popularity of leg vices. The advantages of the various twin-screw (chain-driven or not) front vices; the various tail vices; wagon vices; and the Moxon-style vices are clear. However, I struggle to understand what work-holding problems are likely to arise for which the answer is a leg vice and for which one of the other style of vices wouldn't be better.

I'd be interested to hear what you see are the benefits of a leg vice.

Cheers :wink:

Paul
 

Benchwayze

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I love throwing pebbles into a calm mill-pond, so:

There must be a reason why the Roubo bench went out of favour. Could it be because the Roubo design is so heavily slanted towards the hand-tool woodworker?

I like the Roubo, and I am formulating my own new bench along similar lines. So please note this folks, as I am not just playing Devil's Advocate here...

John :)
 

DTR

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Paul Chapman":2epxk675 said:
However, I struggle to understand what work-holding problems are likely to arise for which the answer is a leg vice and for which one of the other style of vices wouldn't be better.
The other day I wanted to work on the edge of an interior door. I clamped it up to the side of my 5' bench, but the Record vice guide bars stopped me clamping it up "symmetrically", so to speak. Thus I had about 2' of door overhanging one end of the bench. I imagined that if I had a leg vice instead I could have simply unscrewed it and be left with an unobstructed bench front.

Later I realised I could have moved the bench away from the wall and clamped up to the unobstructed rear instead #-o

That's the only thing I can think of. That, and leg vices are typically deeper than cast iron vices (but then so are twin screw...).

Benchwayze":2epxk675 said:
I love throwing pebbles into a calm mill-pond, so:

There must be a reason why the Roubo bench went out of favour. Could it be because the Roubo design is so heavily slanted towards the hand-tool woodworker?
Is there any reason a Roubo isn't suitable for power tool working?
 

Benchwayze

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No more reason than for my dining room table to be unsuitable I suppose Dave! :mrgreen: Seriously:

I sometimes use my vice for work holding when routing, but the vice can get in the way of the router fence; depending on the size and depth of the workpiece. Thus some routing benches don't have a vice.

Seriously, I am just wondering why the Roubo 'vanished', and believe the thick, one-piece top might have something to do with it. Of course Schwarz's designs (in his first book ) didn't have one-piece tops. But they were still quite thick, and could pose problems holding down work for routing.

Regards
John :D
 

woodbloke

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Maybe it's me and it probably is, but a bench is just another workshop tool (probably the most important one if truth be told). For me, it's what you make on it or make using it that's important. What I like to see is the bench in use for making stuff - Rob
 

jimi43

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woodbloke":wd349x0n said:
Maybe it's me and it probably is, but a bench is just another workshop tool (probably the most important one if truth be told). For me, it's what you make on it or make using it that's important. What I like to see is the bench in use for making stuff - Rob
A car's for going from A to B but I will still cry a little tear the day they stop making Aston Martins.....we have to have beauty in our lives otherwise we will all end up like robots! :wink:

Jim
 

woodbloke

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jimi43":39a0vlht said:
woodbloke":39a0vlht said:
Maybe it's me and it probably is, but a bench is just another workshop tool (probably the most important one if truth be told). For me, it's what you make on it or make using it that's important. What I like to see is the bench in use for making stuff - Rob
A car's for going from A to B but I will still cry a little tear the day they stop making Aston Martins.....we have to have beauty in our lives otherwise we will all end up like robots! :wink:

Jim
...and in some ways I agree with that analogy Jim, but benches to me are different somehow. Maybe my view is coloured by my experiences in a professional 'shop, where what was built on it was far more important that what it was built on. My benches were simply lumps of planed 4x4 with a slab of 18mm mdf on the top. In fact makers also had an assembly table (as large as possible) with a 75mm overhang all round. This was by far the most useful thing as it meant that it was then easy to cramp stuff to a flat surface if any complicated routing (for example) was taking place. In fact I saw makers use their bench as a depository for tools and other assorted clutter and build a piece entirely on the assembly table. If you have a look at my 'shop:



...you can see my take-off table (what also doubles as my assembly table), has exactly the same overhang feature - Rob
 

jimi43

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Yes Rob...I don't disagree with you either...I just think there is room for Minis and Astons! :mrgreen:

Actually...having had one for ten years I would say a Ford Focus was the "assembly table" of the car world...with lots of drawers and more than enough room for the occasional "bench dog"!!!! :mrgreen: :wink:

Jim
 

condeesteso

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(aha - just realised the above belongs in 'leftovers bench' thread... repetition, damn)

Agree with pretty much everything :) in that Kind of mood having finished the small bench.
Yes, I imagine the 'Roubo' style to be totally hand-tool focussed, but I can't think of much it couldn't do with powertools, as I reckon it can clamp any shape on either the top or face.
Paul, re the leg vice 'trend' - I do think C Schwarz started it and it may be a sort of 'fashion' at the moment. But they are very simple, cheap, effective and can be tuned to work very well I think. Do pop over and have a play some time!

And yes, a bench is a tool (have said that already on the 'leftovers bench' thread. It will be used as one and I will make the best furniture on it that I am capable of. That do?
 

woodbloke

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condeesteso":2nio6l1l said:
And yes, a bench is a tool (have said that already on the 'leftovers bench' thread. It will be used as one and I will make the best furniture on it that I am capable of. That do?
Happy with that Douglas :) - Rob
 

Paul Chapman

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condeesteso":ansb6tdd said:
Paul, re the leg vice 'trend' - I do think C Schwarz started it and it may be a sort of 'fashion' at the moment. But they are very simple, cheap, effective and can be tuned to work very well I think. Do pop over and have a play some time!
Will do - I'll give you a ring some time before long. The finished bench looks very nice.

Cheers :wink:

Paul
 
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