I have a nice old Wilton 3 1/2" drill press vise, it has a fast action screw and the jaws open to 3 3/4" but are 1 3/4" high so it's kind of too tall for the small stuff I usually have to mill. I tried using a cheap imported drill press vise I got from a yard sale and it was difficult to rely on for a single part and impossible for two, but its very obvious shortcomings made me read about different types of vises.
At the time I looked there seemed to be fewer affordable options. First I checked out Palmgren's low profile vises because they had been recommended for my machine, but decided a screwless vise might work alright, too, and later found some plansfor making them. Then I read about pull-type vises on Kurt's website, which work in a similar way. They were way out of my budget but they seemed like something I could make using a nice piece of left over cast iron I had scavenged for making a milling slide for my lathe.
The finished vise is a good size for holding little things - for comparison it's about the same size as the ones for a Taig, and about half the size of the smaller Kurt. I think it works really well.
Step 1: Design
The 3/8"-20 thread is fairly strong and left enough room so I could have a 1/4" hex drive on the end and use a ratchet for tightening it. The screw is centered in the base of the vise and pulls against the end with the fixed jaw, and the moving nut fits in a channel and is angled at the front where it presses against a similarly angled flat on a dowel pin. Clamping pressure draws the jaws together, and pulls the moving jaw and the nut together against the vise body.
What I found from a quick, non-exhaustive search both features seem to have been patented independently in 1951 in the United States by L. L. Walker and L. Pupura but I've seen it advertised that their combination is manufactured exclusively by Kurt.
Step 2: Parts
The base of the original is an 18mm thick and 15cm long t-shaped piece of seasoned gray cast iron. The stem of the t is 48mm wide, and the arms are 70mm across and are made into the mounting lugs. I have some 1/2" x 2" steel pieces that I thought about making a vise with slots in the sides instead of lugs but I don't know if it's a great material for it.
Both jaws are 2" wide steel bar. The fixed jaw is 1/2" thick and about 1 1/8" long, and the moving jaw is about 3/4" thick, and 1 5/8" long.
The screw is a 179mm long 1/2" drill rod with a 4mm piece of 5/8" pressed on the end. The bearing housing is a piece of 3/8" steel about 1" long and 7/8" wide, and the nut is a piece of steel 1"x1"x1".
There is a 2" 0.250" hard dowel pin, a 2" piece of 1/4" keystock, two 1" 1/4"-20 socket head cap screws, four 5/16" 8-32 pan head machine screws, one 1/2" 8-32 set screw, two 5/8" 2-56 socket head cap screws and a thin 1/4" shaft collar with 3/4" outside diameter.
The base is a piece of 1/2" steel plate I found that already had a stepped bore. It's about 5"x4". I made the clamping plate to fit from a big shaft collar. The locating plate is a piece of 1/8" tool steel from an old circular saw, maybe 1 1/2" long and a close fit to the width of the lower part of the slot in the vise body.
Step 3: Base
Step 4: Nut
Step 5: Jaws
After milling the keyslot on the fixed jaw I fit the key to both parts and pressed them together, marked for the screws and drilled, counterbored and tapped for 1/4"-20 socket head cap screws.