Mini vise-clamp thing

I needed a mini-clamp to hold down my spool holder to my desk and mistertech's design was just about what I had in mind, minus the headphone part. I also shortened the clamp down to 20mm because my desk is very thin. I also wanted the screw to withstand more tension, so I decided to split the original model and print both halves horizontally and acetone weld them after.

If you want the whole bolt or a larger version, check out [the original design](https://www.thingiverse.com/thing:2076034).