The Home Machinist!

I know Kurt is the vise to get if you don't want the moveable jaw to raise as you clamp, but if I place a round rod between the moveable jaw and the work piece, will that not perform the same purpose as the Kurt? It would appear that when the moveable jaw exerts pressure on the round bar, the bar would rotate thus transmitting force in a downward direction on the work piece, as illustrated in the sketch. What are your thoughts on this?

Why would it roll and not just tighten up? Unless the part has a taper where the rod would touch the part?

Richard W.

Mr Ron wrote: the bar would rotate thus transmitting force in a downward direction on the work piece, as illustrated in the sketch. What are your thoughts on this?
VISE TILTED.jpg

The bar might roll slightly as the movable jaw raised up, but no down force would be transmitted to the work piece.

When I square pieces using a vise, it is common practice for me to use a rod, generally a drill blank. I shoot for the center of the jaw, ensuring that the rod won't influence the piece being gripped, thus being held square with the fixed jaw. Once I have the item square on three faces, I then abandon it's use. I have also been known to use a long Allen wrench, with the narrow flat of the wrench serving the same purpose.

H

The Kurt (and maybe some clones, but certainly not all or even most) have a feature that adds pull-down when tightening. There are two small (1/4" OD?) o-rings in pockets on the underside of the movable jaw. With the vise loose the movable jaw is raised up off the bed slightly, but when tightened, the ram/wedge/sled/whatever-you-call-it pulls down and the o-rings compress. This pulls your workpiece down when the jaw moves down.

Adding o-rings to a cheap copy vise that didn't come with them is easy and works. I've done it to my $50 3" milling vise and it made a big difference. No more tapping to get stuff seated down tight against the parallels (or vise bed).

ccfl wrote:The Kurt (and maybe some clones, but certainly not all or even most) have a feature that adds pull-down when tightening. There are two small (1/4" OD?) o-rings in pockets on the underside of the movable jaw. With the vise loose the movable jaw is raised up off the bed slightly, but when tightened, the ram/wedge/sled/whatever-you-call-it pulls down and the o-rings compress. This pulls your workpiece down when the jaw moves down.

Adding o-rings to a cheap copy vise that didn't come with them is easy and works. I've done it to my $50 3" milling vise and it made a big difference. No more tapping to get stuff seated down tight against the parallels (or vise bed).

I wrote to Kurt back in January to see about getting some replacement o-rings for my D-675 and this is the response I got:

"They are just standard O-rings. We don’t even use them on the vises anymore.

You can use a #008 O-ring. They were used to hold up the front of the jaw slightly.

Best Regards,

Michael (Mike) E. Chester

Technical Support / Customer Service

Kurt Manufacturing-Industrial Products Division"

Ted