A good friend designed this and agreed to share. He made it for his kids so they would stop stealing his spring clamps to hold blankets to chairs and such for kid fort purposes.
It’s a simple clamp that could be modified for specific needs. It utilizes rubber bands for tension which are much more versatile (need more tension? use more/thicker rubber bands!) and much cheaper than springs.
The design is meant to be print in place, or all printed at one time.
For example, scaling the .stl file to 60% works well with #8 – 3/4 inch long bolts. You’ll need 3 bolts and 3 nuts. Put the bolts in place before you snap the different pieces apart.