Clamping helping hand

I liked [3dfernando](https://www.thingiverse.com/3dfernando)'s [Helping Hands](https://www.thingiverse.com/thing:2655828), but I wanted a better way to hold them on to my really thin table and also more flexibility in being able to fix them to any other thing, so I thought they would remix really well with my [Mini screw clamp](https://www.thingiverse.com/thing:2902018).

I've redesigned the clamp to have a sturdier, stronger screw. This model still prints really well in place, though it's dependent on **really tight tolerances**. If there's interest I wouldn't mind uploading a looser clamp, though 3dfernando's original ball socket has a pretty tight fit anyway.

PLA is doable, but i don't really recommend it. PETG works wonderfully well for these parts.
I've uploaded a thin version of the clamp (10mm), ideal for thin glass-top tables (like mine) or other supports, and a large version (20mm) that should cover something else. Over that, you're better off with a *U*-clamp like the o