Filament resists going through the FS Cover into the extruder
I have the enclosure finished. I'm having an issue with the FS Cover meeting the entrance of the extruder.
It's easy to get the filament into the PTFE tube and to push it all the way to the FS Cover, but getting past the FS Cover cover is difficult, and takes quite a bit of force to do typically. Is this normal?
And this is also after using a 45 degree filament cutter with Prusament PETG.
Thanks!
Best Answer by ChrisK:
Here is my fix. I printed a bowden extruder cover and put in a PC4-M10 coupler.
Works perfectly.
https://www.printables.com/model/295803-prusa-i3-mk3s-reverse-bowden-set/files
RE: Filament resists going through the FS Cover into the extruder
I'm having the same issue. I had to remove and replace the cover to get filament loaded for my first print inside the enclosure. Had also done a 45 degree cut and was using Prusament PETG.
RE:
So in my case I ended up needing to push the PTFE tube down further into the FS Cover. It has only a little resistance now, but not nearly as much as it did before this.
I feel like i would like a cleaner path into the extruder still, but this works for now.
RE: Filament resists going through the FS Cover into the extruder
This problem bit me again. It looks like the issue is that the tube can't go all the way down into the coupler, and then there's a ledge inside the coupler the filament can get caught up on and not properly slide into the extruder.
So I replaced the coupler with a PC4-M4 press fit pneumatic tube one, but still had issues with filament still getting caught up on the ledge.
Finally today I took a needle file and beveled the internal ledge the filament was getting caught on inside the coupler.
It seems to be working better.
What pneumatic couplers do people recommend that don't have this issue?
RE: Filament resists going through the FS Cover into the extruder
I have this problem as well. Especially frustrating when using TPU.
I've resorted to disconnecting the bowden tube, feeding the filament through and then once it's safely past the restriction I recouple the bowden.
RE: Filament resists going through the FS Cover into the extruder
I also have this issue. Thanks for the info on a cause. Anyone have the issue that unload after filament run out isn't enough to get the filament out of the new FS cover enough to grab it? I've gotten caught in no-man's land -- filament can't be removed and can't easily be pushed down in so you can push it out.
RE: Filament resists going through the FS Cover into the extruder
I've also had this problem - was removing the tube and feeding it in, but I found an easier way...
Make your filament cut a V (that's two cuts) with a knipex cutter (so the end of the filament resembles a pencil tip) then feed it in.
I tried using a pencil sharpener and another jig but it's not worth it, just making two cuts with the knipex works best.
RE: Filament resists going through the FS Cover into the extruder
Thought it was just me, and I have the exact same issue. I am still working on a solution.
RE: Filament resists going through the FS Cover into the extruder
I took the original stock feed cover, drilled the hole larger and threaded in the coupler in. Works perfectly.
The gap between the threaded insert and the extruder is the issue. It gets hung up. The hole needs be smaller in diameter.
RE: Filament resists going through the FS Cover into the extruder
I heat the end of the wire to one centimeter. Then I stretch it and cut the yarn. Remains a tip that fits perfectly.
RE: Filament resists going through the FS Cover into the extruder
Here is my fix. I printed a bowden extruder cover and put in a PC4-M10 coupler.
Works perfectly.
https://www.printables.com/model/295803-prusa-i3-mk3s-reverse-bowden-set/files
RE:
Great suggestion. Any suggestions on removing the slippery tube from the stock coupler? I've had a hard time attempting to grip it to remove it.
RE: Filament resists going through the FS Cover into the extruder
These work much better. Pressing down on the release collar has an actual click - then pull the tube.
https://www.amazon.com/dp/B07ZCNB1L8?psc=1&ref=ppx_yo2ov_dt_b_product_details
RE:
I printed this. I've installed it and given it a go now. The hole for the filament through the PC4-M10 coupler is much larger. I did make the hole for the filament just ever so slightly larger, though.
After multiple filament unloading tests it seems to work really well now.
Here is my fix. I printed a bowden extruder cover and put in a PC4-M10 coupler.
Works perfectly.
https://www.printables.com/model/295803-prusa-i3-mk3s-reverse-bowden-set/files
RE: Filament resists going through the FS Cover into the extruder
The new fs-cover and coupler mentioned by @chrisk did the trick for me as well. Thanks!
I was unable to remove the tube from the stock coupler that the enclosure came with. It refuses to release the tube. I ended up cutting it just above the coupler installing the existing tube into the new coupler. Everything works great now. I still can't get the little bit of tube out of the stock coupler. Oh well.
RE: Filament resists going through the FS Cover into the extruder
Even with the new cover that I mentioned and printed, I still (every now and then) have a small issue pushing in the filament.
I believe I found the solution - the bowden tube is never 90 deg to the top of the cover. If I hold the bowden tube perpendicular (in both directions) to the cover, the filament goes right in every time. Very small tolerances I guess.