Wanhao i3 Extruder Upgrade

Drive block and adjustable tension lever for Wanhao Duplicator i3 v2.1 and other printers with the same setup.

Even if I were able to print with flexible filament with the existing drive blocks, it was always a hassle to load the filament.
This drive block is designed to hug the filament from loading point and onwards. There is simply no way the filament can escape.

Of course I then had to redesign the lever as well to make the parts fit.

This work is inspired by several existing des