FlexAdapt - Use flexible filament with cheap Chinese all metal extruder

thingiverse

I decided to upgrade my Ender 3 with some cheap Chinese all metal extruder parts. I had those laying around for months meant for another project. I found it working mostly good but for the bad filament trajectory. This extruder has a very wide open area after the gears. As I was going to print some TPU feet for my Vorpal Hexapod Robot I had the idea to use this flaw as an advantage. There is a lot of room to design an upgrade part for leading the filament on its way from the gears to the bowden tube. It succeeded on the first try so I want to share it! This modification lets me transport FlexiSmart TPU with 50 mm/s inside the bowden tube without any problems! But beware: I also use Capricorn TL PTFE tubing. The example print perimeters where printed with 30 mm/s, the solid infill with 50 mm/s. No retraction and 2 mm wipe. It has no visible seam on any side. I do use Klipper Firmware with pressure advance though. From what I saw it may also be possible to use a bot of retraction with this setup. It was printed on the LokBuild surface which sits on a flexible steel plate mounted with magnetic foil onto the bed. The surface was heated to 40C and the TPU sticks very well. A bit too good for my taste. TPU also tends to leave "color" back on the print surface which transfer to other prints. For this reason I switched the LokBuild surface with a (self etched) frosted mirror for the second example print. This was headed to 65C. The mirror uses a layer of ferro magnetic foil below and so it snaps tight to the magnetic foil on the build plate. This also worked well and is very easy to remove without residue. Because of my BLTouch it is easy to swap between different surfaces for each print.