I made a video on my channel explaining everything
Please view it Bambu, and fix the extruder design!
Bård
Norway
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What brand filament do you use mostly?
The video is a bit long, I think what you are trying to say is that you think that the distance above and below the extruder wheel is to big and therefore leaves to much space for the filament to bend?
No it is not what i am saying. The inlet hole at the bottom has virtually the same diameter as filament 1.75mm, ANY bend of the filmanent will cause it to jam against the side of the hole, and the amd will try to pull it back, and then again jam it, bending it even more. The bottom hole of the extruder should have been a Funnel like shape, not a straight line with side-cuts. The jams will occur most frequently between filament changes, and it happens no-matter-what filament you use. Remember all filament by design is circulary shaped as it is on a circular roll, and that bend alone is enough for the jams to occur. If the funnel had been like shown in the intro-pic of the video, the filament would never jam even if it had a tiny bit of bend towards the hotend.
For me it’s clear what you mean but all what you show is without the extruder wheel which will guide it also. Besides all of this as far as I know extruder clogging is not a really common problem. I personally never had problems with it either.
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If the end of the filament isn’t quite “right”, it can hang up on the hole going in to the hot end during loading. I agree. But you can fix that by cutting the end of a new roll with some sharp diagonal cutters. Once the roll is started, this is no longer an issue.
The extruder does jam there, though. It happens because the filament gets to its glass transition temp (it becomes squishy), and when the extruder roller pushes the filament towards the hot end opening, the filament “mushrooms” instead of feeding straight. That mushroom blocks the filament from feeding any further, and it also prevents the filament from retracting past the top hole since it’s the same diameter. To fix it, you have to remove the extruder, disassemble it to extract the drive gear so you can get at the “mushroom”, snip it out, and extract the remnant filament pieces. Then, you get to put it all back together again.
And when it happens twice in one day, it makes you feel like you’re losing your mind. 
But it happens because the build chamber is getting too hot for the filament. Prop the lid up and/or turn on the aux and chamber fans to keep the hottest air from accumulating at the top of the chamber (which is where the filament feeds to the extruder, absorbing heat along the way).
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A great explanation. But my filament is not expanded in the bottom part, it is just bent repeatedly.
If what you describe is true, it sounds like it should have bee addressed in design.
Given theory filament would not thicken at the bottom , would a funnel design not give less problems?
I can’t explain “bent”. I don’t think I’ve seen anyone else complain about that being a problem (whereas my “mushroom” example has happened to plenty of people). I’ve been running my X1C for well over a year and this has never happened… Only thing I can think is that there’s some kind of mechanical misalignment in the extruder assembly.
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Millions of X1/P1 users, all printing with filament “bent” by being spooled, and this issue has not commonly occurred in the past 2½ years?
This is not a design failure, it is a problem unique to you and your printer.
…I am on my 3rd extruder unit now since I bought the printer 2 years ago…same problem with all of them, causing jams inside the extruder, where the nozzle is not the cause at all.
You mean to say you use AMS and have never in 2.5 years had a clog inside the extruder / — not the nozzle? Sounds like a miracle to me. I am happy for you! Meanwhile loads of posts and videos on how to clear clogs inside the extruder online. None adressing the problem itself. Thanks for a really productive comment.