We are all aware of the typical wood shop vice, the type that is mounted underneath the workbench and takes forever to open and close by continuously spinning a large handle. These vises normally only open several inches due to the length of the operating screw. They are also not very wide because a cantilevered wide jaw would provide less force the further away it is from the center-mounted operating screw.
Wood worker [Andrew] wanted a very versatile and large vise for his shop. It needed to be wide, provide equal clamping force along the jaw and be able to hold very thick objects as well. One more thing, he wanted it to have a quick release clamping system so there would be none of that continuous handle spinning nonsense.
Spoiler Alert: [Andrew] did it! The end product is great but the interesting part is the journey he had taken along the way. There were 4 revisions to the design, each one making the vise just a bit better.
As you can see, this is a long vise, and it has to be to work how it does. The outermost jaw and those two long wooded 4×4’s are one assembly and can move in and out independently of the base. The jaw is pulled open and after a work piece is put in place, the outermost jaw is slid back to close up any gap. The handle is then turned, spinning an axle that begins to wrap the cable around it. That cable is routed, by way of some pulleys, down one side of the 4×4’s, across the open end and back up the other side terminating where it started, at the outermost jaw. This is where it gets weird, when the cable is pulled tight by turning the handle, the ends of the 4×4’s get closer together and pinches that small block between the 4×4’s. This now prevents the jaw and 4×4 assembly from easily sliding back and forth. As the handle is turned further, the hinge-mounted outermost jaw tilts in to clamp the part up against the innermost vise jaw.
[Andrew] can get a 20 inch long piece of wood in his vise. The vise opens much further but the 4×4’s aren’t able to bend enough to get a good grip on that center block. Clamping force across the jaws is even since the cables are out near the ends of the vice. After 4 revisions to his vise, [Andrew] is happy with how it turned out and plans to incorporate it in a new workbench he is building soon. He’s made 4 videos documenting this project from beginning to end, including all the changes… check them out.
Instead of a horde of magnets for a clutch and a crank to pull on the cable, he should have used a ratchet similiar to this:
http://www.padlockoutlet.com/images/P/3057DAT.jpg
And the middle block that the slides grab onto should extend all the way, so the amount of cable you need to pull doesn’t depend on how far open the jaws are. A material such as rubber between the slide would ensure the gripping force instead of using the leverage of the long slides. That way you’d need only a single pull of the ratchet to tighten the cable at any position, and you’d have a push-button release.
Also for a long vise, I would make the back jaw move along the table. That way you don’t need that much space next to the table, and it is more stable also.
Oh, that’s smart. The first thing that popped into my mind is that this takes up the whole table. (It could also go underneath the table, I suppose)
The whole contraption is going to be integrated under the table, which isn’t apparent in the demonstration video. The “back jaw” is the end of the table, and thus not movable.
Not needed: http://www.popularwoodworking.com/wp-content/uploads/workbench_5F00_intro-33.jpg
I would have used diy gear rack and ratcheting mechanism and final tightening by screw.
I was thinking maybe you could use a cam, driven by a long lever, although it would probably not be that compact.
How about a simple locking pin from the handle to a bunch of concentric holes around the base. Push in to lock
I would be kinda scared of lock failing out due vibrations (working on the piece) or not being properly inserted (laziness) or just breaking (wear). If you would combine getting hit with it with some rotary tool you gonna have a bad day;) But that is just worst case scenario.
Cotter pins are a thing.
This device, though clever, seems like an invitation to very unpleasant backlash as the stored energy unwinds the winch, but for very short term clamping (or perhaps a wine press) it might be very useful.
Quick-release threaded vises are fairly common and offer the advantage of not having to accommodate the stored elasticity of the cables/straps in the tension mechanism. Longer clamping is often done using some variant on ratchet straps (circumferential clamping of frames and round sections) or clamp heads fitted to relatively cheap steel pipe.
You did a great job of using a simple idea to solve several problems. I like the idea in the comments about using a cam action lever to solve the backlash. That would be another inexpensive yet very effective solution.
Anyone who’s watch any episodes of Woodwright’s Shop knows that for clamping big wood, the end vise has a dog that sticks up, and that the whole bench top has stops along it. Mechanically simpler, and as for reliability, they’ve used that design since the 1700s at least.
If you mean these: http://www.bob-easton.com/blog/wp-content/uploads/2008/10/bench-dog-boards.jpg
They have the problem that they only clamp a narrow part of the object. Fine for some purposes, problematic for others. For example, it can only hold against forces that are along the table dimension, perpendicular or diagonal planing will be difficult.
As the video [Leithoa] shows, you use more than just the bench dogs.
Assorted extra bits here: http://www.fine-tools.com/spann1.html. Note the ‘if you really insist on a vice’ one.
The most common clamping method is using a couple of simple wedges (made from scrap) to provide the force. Googling ‘bench dogs’ will show you more than you ever wanted to know.
About a week ago I was trying to invent a clamping system to fit in a tight space. After stuffing about with pivots, springs, cams and the like – oh right, dog & wedges. Doh.
But yeah, let’s re-invent, over-complicate, and perform worse than something that’s been around forever. Because we can, of course.
You can make pivoting dogs with long faces. You can make pivoting dogs with leather straps between two high points, you can make them with multiple hinge points. By utilizing a front vise, and end vise with properly spaced dog holes you can clamp nearly anything. And, not to sound too heretical, you can drill extra dog holes where needed it you have to.
But his vise is an interesting solution, which I will file in my compendium of interesting solutions, which might be useful in the future.
[Andrew] seems to not like having dog holes in his bench top. I don’t see the annoyance but perhaps for projects he builds they interfere. The other problem he addressed with this solution is that except for very expensive end vises you don’t get equal clamping pressure parallel to the vise jaws. Another youtuber John Heisz has built a couple bench vises that he seems happy with. John uses wider guides in his vise than the one [Andrew] currently uses. Which cuts down on the size of vertical work you can clamp.
A solution that is seen in one of the woodwright’s shop that allows for secure clamping along the edge is to drill holes for a holdfast in the bench apron. This is seen in the folding workbench that Roy Underhill builds IIRC this is an antique design. But for $35 bucks and a hole in your bench apron you can securely clamp a variety of work.
@jpa
There is a method to clamp using only bench dogs, a holdfast , and scrap wood. If you cut a 90* fish mouth in a piece of scrap this can be clamped by the holdfast against a corner and it keeps work from pivoting around the dog regardless of how you plane.
https://www.youtube.com/watch?v=WNrof3cd1cA
Around 0:50, anti racking inserts. Screw the vice, I just need me some of those.