Creality CFS tensioner using POM wheels for K2+ and Hi Combo

Please see my video on how to print and assemble: https://youtu.be/_eJe7B8Vqws

Parts list for one CFS unit (4 spools)
4× standard POM wheels
4x M3x20 screws
4x M3xL3OD4.5 heatset inserts

• A complete set of four tensioners even fits on the build plate of the Creality Hi not only the K2 Plus.
• Add the M3 heatset inserts into the designated holes on the tensioner arms. You can use a soldering iron, or if you’ve seen my earlier video, a stealth press makes this super easy.
• The POM wheel should snap into the arm.
• If you’re using them, glue in the little cover rings to stop the POM wheel from sliding out.
• Insert an M3x20 screw into the funnel-shaped roller-wheel. You should see about 5mm of the screw sticking out from the axle tube.
• Push this tube and screw through the hole of the POM wheel and then fasten the other small printed wheel using an Allen key. The POM wheel should spin relatively freely.
• You might need to clean out some debris from the screw holes on the new 3D-printed base piece, regardless of whether it was printed with or without supports.
• Carefully pop off the original bumpers and springs from the CFS unit. Hang on to these; we’ll actually reuse the little bumpers and springs.
• Remove the two screws holding each of the original bumper bases. Keep these screws, as we’ll use them to attach our new bases. I kept the original bases too, just in case I ever want to restore it to its original state.
• Insert your 3D-printed spring into the tensioning arm. Make sure the open end of the U-shape is facing away from where the POM wheel is.
• Now, you’ll need a short piece of PETG filament to attach the assembled tensioning arm to the replacement base. I initially tried using PLA, but it snapped when I bent the ends to keep them in place. PETG is much more flexible and won’t get brittle over time. Just pass it through the holes and melt or bend the ends.
• Fasten the complete new base assembly in place of the original bases, using the original screws, with the tensioning arm hanging down.
• Use the original springs and bumpers in the new bases. These new ones provide a slightly longer range of motion for the bumpers though using the same springs.

3D printing settings

No supports are needed. No brims either, especially if you’re using that lovely epoxy resin plate that came with your Hi. For the springs, I recommend using mouse ears for better adhesion, unless you have that epoxy plate. I used PLA, with 3 walls, and the standard 0.2mm layer height preset.