Need to clamp some parts together in a tight space when other clamps will not fit? Here is a little spring loaded "F" clamp that just might do the job. Regular "L" clamps use a little wedge but often slip. In this design the pressure is applied to the moving jaw by a spring loaded movable ferrule for varying work thickness.

Suggest printing information: Any strong material. Solid infill.

The clamp has four parts and requires threading (tapping) a hole for a screw. It needs the screw and a compression spring. The hole in the adjustable ferrule is .05-inch (1.27mm) and can be drilled out and tapped for a screw. (Because the bar has small detents in it, the screw only needs to be finger tight to avoid slipping.) Although I used wing screws, socket head cap screws would be ideal. Regular pan head screws will work as well. Re-drill the hole to .106-inch diameter and tap for #6-62 screw, or re-drill to 3mm and use a M4 screw.

The spring is about .31-inch (7.8mm) ID and the length can be about 1-inch (25mm) long. The "L" shape retainer needs to be cemented to the sliding jaw back as seen in the photos. This helps grip and operate the clamp easier with one hand.