Replies

1. 
   flairwoodworks | Nov 13, 2008 08:34am | #1

   I thought about it but ultimately bought the Veritas vise.  It has been done - the Veritas is relatively new to the market.  In one of the Taunton workbench books by either Lon Schlening or Scott Landis (I think Landis) is a bench with a chain driven twin screw vise.  I don't recall which of the two or whether the chain could be disengaged.

   Edit:  Of course, as Adam would point out, wooden twin screw vises have been used for centuries.

   Chris @ www.flairwoodwork.spaces.live.com

    - Success is not the key to happines.  Happiness is the key to success.  If you love what you are doing, you will be successful. - Albert Schweitzer

   
   

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   Edited 11/13/2008 12:35 am by flairwoodworks

1. 
   WillGeorge | Nov 14, 2008 05:11am | #2

   is a bench with a chain driven twin screw vise.

   First off.. I do not have a twin screw vice.

   Second off.. Probably never will..

   Third off.. I cannot afford any more to try.

   Forth off.. I love my pattern makes vise! Yes a China or other... rip-off but it WORKS! I always have something I need to angle in the vice a bit.. without looking for some old stick to fit.

    

2. 
   BrianDerr | Nov 15, 2008 11:07am | #3

   Both the vices on my bench are twin screw, but not linked by chain (or any other way). I just bought the heavy duty German screws from Woodcraft at $50 each and mounted them in pairs. I really don't mind turning both shopmade handles at once, and like the control of being able to rack slightly, i.e., control independently. The jaws and apron are 3" thick maple. This setup did take some time fitting, but what else is new.

   Brian

1. 
   donolee | Nov 20, 2008 04:18am | #4

   That sounds like a good idea. I like the "racking" option of two independent screws. Also you can't beat the price. Thanks.

3. 
   JulianBE | Nov 20, 2008 06:52pm | #5

   I used two very cheap small conventional vises mounted about, oh, 12" apart on the end of my bench.  The fixed, or inner jaw, is attached to both vises.  The moving jaw is also the full width of both vises, but only fixed to the left vise, just resting on the guides of the other vise.  The left vise has the little rising metal dog that makes that vise my tail vise as well,

   To assemble: I cut the jaws and secured the inner jaw to both vises to make sure the faces were coplanar, then I bolted the vises to one piece of 3/4" mdf, ensuring that the jaw face would end up perpendicular to the benchtop, and then screwed the assembly to the bottom of my benchtop.  Then I installed the outer jaw and planed them level with the benchtop.

   To use, keep the right hand vise a little more open than the left, insert workpiece, tighten left vise, then tighten right.  Loosen the right vise first.  It's really very quick and effective, especially with the little quick-release levers on the vises.  I don't find a need for the behemoths some attach to their benches.

4. 
   AdamCherubini | Nov 20, 2008 08:27pm | #6

   You have to be careful about how to react the rack top to bottom.  If you want to clamp stock between the screws, any set up will work (preferably looser the better).  But the trick is clamping stock above the screws.  The Veritas reacts this in a tight toleranced garter.  Garters are tricky because they are prone to wear.  And tight garter mean the jaw will bind side to side if the screws aren't moved together. 

   A wooden twin screw has a lot of advantages. Stock placed above the screws is reacted by the large screw heads.  The jaw can be loosely fit and garterless, allowing you to clamp irregular shaped  pieces with no dificulty.  Clamping stock above the screw heads is not really possible.  The jaw will just rock.  So mount the screws as high on your bench as possible.  The screw heads on my german bench are about 1/2" below the surface of the bench top. 

   The screws can also sag in their nuts.  You may need long nuts or spacer blocks between the screws and the bench top to stop that. On my german bench, the screws run in 16" deep holes I bored into the solid bench top. 

   Failing that, consider a tight hole at the apron, and set back the nut several inches.  This will require longer screws.  I would design it so there are no threads for the first 10" or so, such that the tight hole never sees threads. This will limit the capacity of the vise to 10"-jaw thickness, but that should be plenty. 

   Adam

   P.S.  I know of 2 wooden screw manufacturers- bigwoodvise.com and Mike Siemsen.  These won't be cheaper than a manufactured vise but they probably are better when you take into account what I've written above.

5. 
   tiburon | Nov 21, 2008 06:26am | #7

   Hi
   I just built a work bench and am looking at a twin screw vise and a tail vise. I think I may "bite the bullet" and buy the "off the shelf" one. I hate to re-invent the wheel if I don't have to. I do hate the price though.

1. 
   davcefai | Nov 21, 2008 08:14am | #8

   Something I will be trying this weekend:
   I cannot get a twin screw vice here and buying abroad will cost a fortune in shipping costs.So I bought a B&D "Workmate" lookalike for about $30. The top is essentially a twin screw vice.So the hardware will be screwed to the bench and I will replace the wooden (MDF) parts with beech.It won't be perfectly satisfactory but it should be usable. If I take a lot of trouble over it I should then find a plethora of twin screw vices on sale at the flea markets just after I complete the job :-)

1. 
   WillGeorge | Nov 21, 2008 03:20pm | #9

   It won't be perfectly satisfactory but it should be usable.

   Forget.. perfectly satisfactory and dwell on.. it should be usable.

1. 
   davcefai | Nov 21, 2008 06:05pm | #10

   I take it that your glass is half full rather than half empty :-)

2. 
   dkellernc | Nov 22, 2008 03:25am | #11

   "HiI just built a work bench and am looking at a twin screw vise and a tail vise. I think I may "bite the bullet" and buy the "off the shelf" one. I hate to re-invent the wheel if I don't have to. I do hate the price though."

   Unless you consider your time free, you will not be able to do better than manufactured vises.  They are built in high-speed and highly efficient factories, and it will easily take you about 10 hours to build and mount a chain-linked twin-screw vise made from off the shelf metal bench screws, bolts, sprockets, and chains.  It will likely take you more than 20 hours to build a wooden tail vise with an off-the-shelf metal screw. 

   For a tail vise in particular, they're complicated beasts, and require some very high precision planing and fitting to get them to work properly.  It took me 2 attempts to get it right, and I've got decades of woodworking experience.  The total time invested for the tail vise was about 25 hours, not counting the failed attempt, which I tossed in the "to be burned in the woodstove" pile after putting about 15 hours into it.  This is even after laying out the design several times in a CAD program, as most of the time wasn't design flaws, it was the tolerances required to get the vise to travel smoothly and not sag below the benchtop more than about a 1/32 of an inch or so.

   One of the best deals you can find in a front vise is find a used, and usable, antique Record quick-release on e-bay or at a flea market.  There's good reason why they go for $50 and up.