Direct Drive Mod for Flex Filaments

thingiverse

This modification/addition to the direct drive extruder can make feeding flexible filaments more reliable. I have a Qidi X-plus printer and the specs states that it can print TPU at 30mm/sec print speed but I found that I have to slow it down to almost 15mm/sec to get it to feed reliably because otherwise it would jam. I thought of getting a Flexion extruder, but it would take too much work to adapt so I decided to make this thing. With this installed, I can print at 30-40mm/sec with no problems. You slide this sleeve on to the extruder gear and it will basically remove the gap where the TPU/flexible filament can jam into. You may have to sand it down a little to reduce the friction as much as possible because it is a tight fit. It does add a little friction, but the stepper motor is not bothered by it that much. You must add a very small amount of superglue to tack it on (very little…like a small drop and only the half side of the tab). My original design had a vertical tab so you do not have to glue it because it acted as a rotational stop, but then you would not be able to manually disengage the idler using the lever. I thought that tacking it on was a good compromise. I must re-iterate - Please do not use too much glue. You must be able to pry it out if you must replace it in the future or want to remove it for whatever reason. I included the Fusion 360 file if you decide adapt it to your liking or if you want to add a vertical tab so you don’t have to glue it. This works on Qidi X-plus (and thus the X-max because it has the same extruder assembly) but I cannot be sure that it will work on other direct drive extruder systems. All direct drive extruder designs are mostly similar, so it may work on without further modification – just do not blame me if it doesn’t