This is a small desktop vise I designed for a project and for personal use.
At full scale it is about 6 x 4" and has 2.75" of travel.

You will need a 6" 3/8" fully threaded bolt, (2) 3/8" nuts, and I used (2) metal washers with (2) Nylon washers against the vise base.
The nut for the slide along with the knob will need to be glued. I also chose to lock in the back nut with glue so it does not come loose.

I have included the files for a replaceable grooved block and a blank block.

I printed mine with PLA at 30% infill and 1.6mm wall thickness