What is the NEW Quad-I Vise?

by the designer and inventor of the original Quad-I Vise, Stanley Dornfeld

The Quad-I Vise was redesigned for the Machinist.  Why?  Because all the earnings coming into the machine shop, come in through the hands of the machinist first; and Quad-I is here to help him.

The Clamp
The first order of business was to build a very good clamp.  The “Straight Line Clamping” feature employed in the Quad–I Vise applies all of the clamping force to hold the part.  The vise is very sensitive to feel.  When needing a light force, a light touch can yield one.  When needing a strong force for holding, the extra clamping force developed by “Straight Line Clamping” will supply one.  The box way design of the moving jaw has a very close running fit, less than one thousandth of an inch, yet it still has a free running slide.

The Fixed Jaw
The second order of business was to have the fixed jaw in front to align the vise to the machine’s coordinate system.  This is a big advantage in helping the machinist keep his mind clear of work a rounds and confusing extra steps needed to make accurate parts.

The fixed Jaw in front enabled other advantages to emerge.  The Acme screw passes through the fixed jaw.  The Capture nut which is attached to the screw applies the clamping force to the fixed jaw.  This same force is also pulling the moving jaw in to clamp the work.  These opposing forces neutralize each other and create a balance between the two jaws.  This system offsets the pressure against the fixed jaw allowing it to remain a stable zero reference for repeatability.

The fixed jaw in front has made loading and unloading parts much easier, because part loading is done very close to the machinist’s body.  Therefore the Quad–I Vise is also more ergonomic.

The entire working mechanism of the vise is embodied in the fixed jaw.  Loosening one small screw allows the machinist to remove all the moving pieces from the vise if necessary for maintenance.  This means the vise may be left bolted to the table with the fixed jaw and its removable jaw plate intact.  When reassembled, machining can proceed as it was, as none of the locating references have been disturbed.

The Moving Jaw

Before the 1970’s most of the vises had one glaring difficulty.  The moving jaw lifted, which in turn lifted the part when clamped.  Most of us used “dead blow” hammers to re-seat the part for machining.  In the early seventies I saw my first Kurt Angle Lock vise.  It did what the other vises could not do.  It kept the moving jaw down.  It was a big deal and a big help. 

Kurt came in and sold over the other vise manufacturers because those manufacturers were not paying attention to what the machinist needed.

All that was needed was to machine a close running fit for the moving jaw.  These moving jaws were sometimes lifting twenty thousandths of an inch.

When I redesigned the Quad-I Vise I decided to remove the lock down mechanism.  The lock down system uses some of the clamping force to hold the moving jaw down.  That meant you needed to use about fifty percent more force to hold the work as you would with out it.  You first had to tighten the jaw enough to take up slack in the mechanism; and then to that, add enough to hold the part.  To me, what was most the most annoying is the inability to feel how tightly I was holding delicate pieces.

The Quad-I Vise now has a very close running box way fit.  The target allowance is between .0005-.001 inches.  The Dura-Bar iron used in the vise has quite a bit of graphite in its matrix and is nearly self lubricating which helps prevent galling and gives the vise a long working life.

The moving jaw was also “folded” to make a shorter vise which can still hold over six to seven inches.  The moving jaw has what I call a integral “tongue” which sits down inside the vise body and protrudes toward the fixed jaw about one half of the moving jaw length.  This jaw in conjunction with its bottom plate develops a nice long bearing surface for the clamping process.

The Acme Screw
Keystone makes very smooth rolled Acme screw stock.  The six inch vise uses a 1 inch 6 lead Acme screw.  The screw’s pitch diameter and lead combination yields a 3.3 degree helix angle for good clamping leverage. It is an alloy screw with some degree of work hardness.  I chose the Keystone Acme screw for its efficiency of manufacture and its strength.

The Acme screw stock in combination with the capture nuts yield the advantage of tandem vises which can hold very large pieces. Combining two Quad-I vises and a three foot long Acme screw assembled into the tandem setup can hold over twenty four inch long parts.  The screw stock also comes in six foot lengths.

The Quad-I Vise Body
The vise body accommodates bolting to the table through the inside for close multiple vise nesting.  The sides of the vise have “keyhole” slots for side mounting as well.  These slots are back counter bored (milled) for socket head cap screws. This feature helps accommodate end work and edge work on hard to hold pieces.

The Capture Nuts
What is a capture nut?  Well, it is a nut which fits an Acme screw thread; but is not a working nut.  Its purpose is to hold on to the screw and not slip.  To do this the capture nut has a specially designed thread to help the nut bind to the screw.  It also is a split nut which uses a socket head screw to constrict it around the Acme screw.  If it were not for this nut design, I would not have been able to use the pre-threaded rod.

The Over All Picture
A gentleman called me to buy another vise. “You know what like about this vise?” he said.  “It’s so easy to clean!” I liked that.

At a later time I heard, “The first thing I do when I receive a vise is get the body grinder out and radius all the sharp corners.”  I don’t like sharp corners either.  So I’ve milled radiuses on the vises so the machinist will feel more comfortable working around them.

“I really like the fixed jaw in front.  It makes loading and unloading the vise easier.”  “We are from Viet Nam and we are shorter than you Americans.” I smiled and thought, of all the ideas and features I built into this tool, I would have never suspected that. And I laughed out loud and told those fellows that.  They bought two more vises. I delivered them and they took me to lunch. Good people.

I’ve tried to make the vise as versatile as is reasonable without getting it too complicated.  I’ve been in the trenches too, as a machinist.  So I’ve tried to address the aggravations which have annoyed me the most.

I hope you like our new Quad-I Vise.

Best regards,

Stanley Dornfeld