Extrusion issues halfway through the print

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I have had my Ender 3 pro for about 2.5 years and recently it has been stopping extrusion when it is 5-7mm through the print. I tried different extruder motors and a new mainboard but that did nothing. The only thing I can think would be happening is the issue doesn't start until the parts are heated up. This has seemingly showed up out of nowhere. Any help would be appreciated.

I modified (removed bowden tube feature) for a direct extrude design. Purchased an aftermarket plate that allowed me to mount the extruder right above the hot end. This prevented 'binding' of the filament within the bowden tube, because you are basically left with a very small spacer between the extruder and the hot end. What I found was the extruder was getting so hot that it was softening the filament as it was passing through the gears and crushing it into more of an oval shape. When I had prints that required more frequent retractions, this distorted shape was causing the filament to get stuck in the tube and preventing extrusion. Another option could be to print/mount and install a fan for the extruder to keep it cool, but I have found that I even with the extra momentum of the extruder attached to the X axis, having this extra mass has not introduced any vibration issue & have actually improved my prints with temperatures @ or above 240C.

Since it's 2.5 years old I'm not sure what firmware you have on it or if you have upgraded it.
If you haven't gotten a thermal runaway error...watch the hotend temp during the next print.
If it fluctuates at all, then it's most likely the thermistor.

I updated to marlin recently and the problem persisted. When you say fluctuates, how much do you mean? I print at 205 and every now and then it says 206 or 204 but that doesn't seem out of the normal.

Yes that's normal.
I had to replace mine about 5 weeks ago. It was jumping from 200 to 260, than 180.

So no other ideas?

Not really..your replacing parts..have you checked your slicer settings..??

Other than that, I don't have any idea.

Since your hotend is ok, what about your bed..??

I don't feel like it is the slicer (I use Cura) because it was working before. What about the bed? The Extruder motor just stops spinning. The printer doesn't stop or give me an error. It just keeps going without extrusion.

Sorry, I was stuck on it happening when things got hot.
If you've replaced the stepper & the board..I'd look at the wiring...but
You said "it has been stopping extrusion when it is 5-7mm through the print" so read this.

I just replaced the extruder thermistor, and the problem seems to have been solved. I got through a 125% sized Benchy. Before, I could only get halfway through one. Thanks for you feedback.

Good to know. What made you decide to replace it, you posted above that it seemed fine..??

Because I replaced everything else lol. I pretty much rebuilt the whole printer. It still doesn't show any difference on the LCD screen though. The temp is reading just the same, so I don't know how it made a difference but apparently it did.

I took about 3 days before I noticed mine. I wasn't watching long enough, once I realized it was stopping between 15-30min. I watched it the screen the entire time and caught it.

So.... the blasted thing cut out on me again. I am just baffled and have no idea what direction to take.

Ok, maybe I was missing something. Anyway, thank you for all your help.

What caught my attention in the article was the section about overheating the extruder motor driver. Maybe my cooling fan is going bad?