FlexAdapt - Use flexible filament with cheap Chinese all metal extruder

thingiverse

I chose to upgrade my Ender 3 with some affordable Chinese all-metal extruder parts I had been saving for months, meant for another project. They were working pretty well but had one major flaw: the bad filament trajectory. This extruder has a very wide open area after the gears, which was initially a problem. As I was printing some TPU feet for my Vorpal Hexapod Robot, I realized I could use this weakness to my advantage. There's plenty of room to design an upgrade part that guides the filament from the gears to the bowden tube. I managed to succeed on the first try, so I'm excited to share it! This modification lets me transport FlexiSmart TPU at 50 mm/s through the bowden tube without any issues, but be aware: I also use Capricorn TL PTFE tubing. The example print perimeters were printed at 30 mm/s, and the solid infill was printed at 50 mm/s. No retraction and a 2 mm wipe were used, resulting in no visible seam on any side. I'm using Klipper Firmware with pressure advance, but it might also be possible to use some retraction with this setup. I printed it on the LokBuild surface, which sits on a flexible steel plate attached to the bed using magnetic foil. The surface was heated to 40C, and the TPU stuck very well - almost too well for my taste. TPU also tends to leave color residue on the print surface, which can transfer to other prints. For this reason, I swapped out the LokBuild surface with a (self-etched) frosted mirror for the second example print. This was heated to 65C, and the mirror uses a layer of ferro-magnetic foil below that snaps tight to the magnetic foil on the build plate. This worked well and is very easy to remove without residue. Thanks to my BLTouch, it's easy to switch between different surfaces for each print.