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 designs (see Remix source files), but I had to re-design it from the group up, making completely new parts (base and lever).
The nub file is not my design. It comes directly from thing:1516255 by dumbcomputers.
New lever (extarm3_v4)
I found that the pressure on the filament / extruder gear might be a bit high. I've edited the lever so the nub can now go somewhat higher (into the lever). I haven't tested it yet so I'm keeping the old (extarm3_v3) here for now.
0.1 (or 0.2 with adaptive layer hight)
The drive block prints on its back.
The lever can be printed on its side or with top down (thats how I printed it).
Clean up the parts and make sure the lever fits nicely on the drive block cone. Otherwise sand it down until you get a nice snug fit.
Install a M3-nut in the adjustable arm. You might need some force to get it in. It's a tight fit.
I recommend drilling up the filament tube with a 2mm drill. You can get the filament through without doing so, but I still suggest you open it up a bit.
Install the v-block bearing in its seat. It should more or less snap into place. Fix it with a M3x10 from the back. Make sure the end of the screw is flush with the front of the lever. Otherwise you won't be able to fit the heatsink properly. There is plenty of room for the screw head between lever and drive block.
Make sure the bearing can rotate freely. Otherwise take it out and clean up the print some more.
Installation onto extruder is the same as for the original drive block.