Overly complicated vise stop

[petertha]

One advantage of the Kurt mill vises & their lookalikes is that they they have rectangular jaws. They lend themselves to jaw replacement, sacrificial jaws and those clamp-on work stops. I'm a big fan of stops. They help a lot with accuracy as the part can go in & out as often as you like & preserve the same position. Unfortunately my (Bison 5") mill vise has prismatic jaws. I shouldn't complain because its super accurate. But you cant use the typical rectangular clamp on stop due to the taper on the back face & also there is very little lip. I have a stop that comes in from the side but it takes a little longer to set up. When you have little parts around the middle of the jaw, the clamp-on kind of stops are easier.

So I came up with this arrangement. Its basically a steel bar with a bolt on front lip stop. It saved me milling away a bunch of material from solid & gives me flexibility to attach different thicknesses or custom shapes of stop plates if I choose. I had to relieve a notch in the top bar so it would clear the jaw protrusion. The rest lies flat on the top of the vise block. My vise also has big cap screw heads protruding proud on the block but I decided to not relieve for those or there would be little left of the bar to lay flat on. So my range is just a bit limited between the socket heads but it will be fine.

[petertha]

The overly complicated part comes with the clamping mechanism. Its funny how you take a POS hardware store C-clamp for granted. I wanted a shoe that would clamp tightly, accurately & in-line as much as possible with the stop area. That means the foot has to be able to free rotate about the threaded screw. If its fixed to the screw the whole assembly skates sideways as the shoe makes contacts & torques against the surface. There is a reason why clamp feet are designed this way. Many commercial clamp shoes have a ball in socket which nice, but not easy to replicate. Some are just an open cup with a peened over end on the screw.

I machined what looks like a big thumbscrew with 1/4-28 TPI threads from 12L14. The end is tapped 4-40 for a flathead 4-40 screw which retains the brass shoe and a nylon spacer washer. It gets blue Loctite so it retains the right clearance fit. The shoe is countersink so the bolt head sits slightly inside.

[petertha]

Clamp body parts. Plain 1018 mild steel. I probably should have machined the surfaces flat but just a bit of hand filing & wet/dry on a glass plate made it acceptable.

[petertha]

I made a shorter length stop finger just to give me more options around different parallel heights. And finally the blackening treatment on the bar parts which came out blotch free this time. I think there is something beneficial to those scuff pads as a surface treatment, methanol wipe to remove any oils, handle with rubber gloves etc.

The more I play with this stop, the more I like it. Its so quick to set up. And it stays put with a very positive grip.

[jjr2001]

Very good looking vise stop. Easy on. Easy off and great for small parts.

Cheers, JR

[bruce.desertrat]

Very nicely done.

[DIYer]

Thanks petertha! We've added your Vise Stop to our Vises category,
as well as to your builder page: petertha's Homemade Tools. Your receipt:

Vise Stop by petertha

tags: vise, stop

[Toolmaker51]

It's not a "Overly complicated vise stop", you worked around their design to accommodate a needed feature. It [the frame] might have been made one piece; no fun in that. Proof's in the pudding, that it remains in place. Rather critical function for a stop.
I notice at least one side of the body is drilled and tapped, opening a new opportunity for an extended stop.

[petertha]

Thanks.
Yes both ends of the top bar are tapped 6-32, same pattern for consistent setup. The front side (with the notch) is intended to accommodate different sized/shaped stops. I just made 2 for now of different depths. For example if I have a thin part, then the appropriate parallel will also be high. So the stop must have a shorter overhang without conflicting with the parallel. The other end of the top bar has the end plate bolted on. I tried to get the center of the clamp foot aligned close to the jaw corner as possible so tightening minimizes any coupling moment. Endless fun for a couple bucks of materials LOL.