JGMaker Magic Flex Filament Extruder Upgrade

thingiverse

Like many others, I was having problems trying to print TPU using a Bowden extruder, in my case a JGMaker (JGAurora) Magic 3D printer. I started with thing:3485470 for the Ender 3, but I needed to re-render it so that I could make the adjustments to the feed hole height, spring length, and other dimensions that would make it compatible with my Magic. I have posted the STEP file here, so that others can make further modifications if they like, without having to start from scratch. I am now printing TPU with no problems at 30 mm/sec, and probably I could go faster. Others have also replaced the plastic tube from the extruder to the nozzle with a higher quality one, supposedly to lower the friction, but I did not do that. I have used this extruder with TPU flow rates up to 110% with no problems. The only problem I have had is with one specific brand of TPU that was wound very tightly onto its spool and tended to stick to itself. The extruder had difficulties pulling the filament, and tended to slip. I solved this by pulling sufficient filament off of the spool and laying it across the room, so that the extruder could freely pull it in. This was not necessary with two other spools of TPU that I have used, nor with several PLA and one ABS spool, so it appears to be more a problem with that specific TPU spool, and not with the extruder itself.