This is a customizable tool maker's clamp
This video gave me the idea for making these: https://www.youtube.com/watch?v=1tRgONkbEdM
Dimensions can be altered to suit your needs. Use the Customizer app to alter the clamp dimensions.
Shown are two versions of the clamps. One version was printed to use 1/4"-20 threaded rod, while the 2nd version uses M3 screws.
2x threaded rod pieces or screws
2x nuts to match threaded rod
Loctite to adhere nut to threaded rod
Cut threaded rod to desired length using a hacksaw
Use Loctite to adhere nuts to the end of the threaded rod;
Press bolt knobs onto the end nuts of the threaded rods.
Press two nuts into the captive nut holes in the clamp.
Thread rods into the holes of the clamps.