Hi all. This is an update to this post. I don't know what else the community can do to help, but I figured I'd throw some more content up there and give something bored people to look at.
Since the last update on that post, I tried working on the printer in freezing temperatures (not really but it's cold in this house) with extremely precise practices on assembling the hot end (the same hot end I had haphazardly assembled dozens of times and printed with zero issues) and yielded zero progress. Today, I tried a brand new PTFE lined heat break, along with a brand new Capricorn Bowden tube (I already had one but I needed more tubing for the heat break). Clogging in the same exact way in roughly the same amount of time as every other attempt. It's as if I've not tried anything, literally nothing is effecting the results.
I considered ordering a fancy micro-swiss or ed3 hot end, but at this point, including the stock hardware, I've gone through 6 heat breaks, 3 heat blocks, a half dozen nozzles and a foot of Bowden tubing, none of which did anything to fix my problem (or even make it worse). I would look to the extruder, but I outlined in the previous post the testing I did to rule that out (able to run >1m of filament at high and low speeds through the Bowden tube).
I'm at the end of my wits. Perfectly good printer cranking out multiple high detail prints a day, now completely useless over something so stupid as clogging. Where the hell else can I look? Could it possibly be some sort of software/firmware issue, where Klipper isn't sending or receiving the right commands or something? I know my slicer settings are at least good enough because I've tried both prints that have completed dozens of times as well as new prints with drastically reduced retraction. Do steppers need to be tuned over time? I don't think it makes sense that after a year it'd suddenly become so uncalibrated it's unusable, and when I tried calibrating it before I was just unknowingly calibrating against mild clogs, but I don't know where else to look.
You can try to use this hotend fix to avoid clogging https://www.thingiverse.com/thing:3203831
Also, make sure to replace Bowden coupler by new one
My hotend has been modified to avoid the need for this mod. (The Bowden tube runs all the way from the extruder motor down to the nozzle.) My couplers are all working properly as well. I was actually worried that the new coupler I put on one end was cutting the Bowden tube and somehow getting remnants to the nozzle, but I've mostly confirmed this is not the case.
"the Bowden tube runs all the way from the extruder down to nozzle", what kind of modification did you do because that's how most Bowden setup are from what I know. This video explains why the fix works https://youtu.be/7tCxO17XZtw
My printer originally had Bowden tube that goes from the extruder to the top of the heat sink. If you have a PTFE lined hot end, there is another Bowden tube fixed inside that runs from the top of the heat sink down to the nozzle. If you have an all metal hotend, there is a shorter Bowden tube that goes from the top of the heat sink to the top of the heat break.
I modified my heat sink by drilling out the top, where the first tube stops and the second tube starts, such that the Bowden tube coming from the extruder goes all the way through the heat sink to the nozzle/ heat break. This was done after the clogging issue began, and did not effect the results in any measurable way.
My original understanding was that most Bowden setups were like mine, with a long Bowden tube at the extruder and a small one fixed inside the hotend, but after watching your video it looks like those printers come the way I've modified mine to work, and that mod/ fix is supposed to make it work like mine originally did.