I created it after I tried to use this feeder for 1.75mm filament and found that it needs some additional guidance under the extruder motor.While printing test prints with the new feeder and 2.85mm filament I also had some noise coming from the feeder which has its cause by the filament not really centered on the pressure bearing. So I adapted the addtional guidance for the 2.85mm version too.With those two pieces I can switch the extruder from 2.85 to 1.75 just by switching the snap on guide.I tested the 2.85 with some prints, works perfectly, noise is completely gone.The 1.75 I only tested that the feeding really works, I want to change the bowden tube, the PTFE coupler and the nozzle before I do my first print. Maybe this gets an updated after the first print, but so far it looks very good.Printed 0.1mm layer height and 100% infill on the side with supports by purpose even the part would print very good on the back side because this way the parts are much stronger at the sections where it needs to be: the hooks where it snaps onto the feeder and the middle part where it has to bend a little when you snap on and off.NOTE: This could be called version 2, I withdrew the first one as I experienced filament grinding with the 2.85 version. I realized that the additional guidance caused this because the filament is too strong to be bent enough on the resulting 1cm between the guides where the extruder and the pressure bearing are if the filament can not move a bit. So I changed the round hole to long holes since only the position of the filament centered on the wheels is important.