My 3D printable helping hand system is tested and works great for holding wires / cables when soldering. I just officially added all of the STL files to the Stickvise website. Here are a couple pictures of the fully assembled system.

This is a worthwhile upgrade even if you already have a third hand or helping hand setup because these stay with the vise, making it easier to move your project around.

Head over to http://stickvise.com/hacks/stl-downloads for more instructions and to download the STL files!