Brooke Chalmers

I dusted off an Ender 3 Pro that I had sitting in my closet for a few years, and I'm having some trouble with printing. Specifically:

• The first layer prints perfectly fine

• The next few layers have a lot of nozzle dragging (sometimes causing the stepper to skip in the Y direction and offsetting the rest of the print!) and lots of "clicking" from the extruder stepper (can't push filament through)

• The rest of the print goes fine, albiet with more clicking from the extruder stepper

I've played around with a few parameters to try to solve this, but haven't had much luck.

Esteps: I followed the advice I found of drawing a line 100mm from the extruder, commanding that stepper to move by 100mm, and checking the difference. It seemed like by this test the extruder was underextruding by around 5% or so.

Bed leveling/Z-offset: I've been leveling the bed by sliding paper underneath the nozzle and turning each corner until I hit exactly the point of no resistance, and confirmed that the center is the correct height as well. I've tried playing around with Z-offsets too (in both directions) -- as expected, moving the nozzle closer to the bed causes problems with the first layer (too smooshed) and moving the nozzle farther from the bed leads to poor adhesion (even if I add glue stick).

Flow rate: This is the parameter I've had the most success with so far -- setting it to 80% instead of 100% removed the nozzle drag problem entirely, although I still hear the extruder stepper clicking occasionally when printing narrow columns. That said, it makes the prints have much worse surface obviously. I haven't tried more reasonable values because I'm worried I'm treating a symptom, not the root cause...

Z-axis motion: Z-axis moves smoothly by hand if I disable the steppers. There are a few spots where I can feel it goes a bit harder, but it's around 10mm high and the corresponding layers in the print look fine.

Extruder clogging or other factors: I did a cold pull, came out clean. Filament flows smoothly when I push it by hand.

Details:

• Slicer: PrusaSlicer, built-in Ender 3 Pro preset, "Generic PLA"

• Filament: PLA, it's "3D Solutech" brand, I bought it a few years ago and it's been sitting out in a closet (not an airtight box or anything). I live in New England so not a particularly humid climate.

• Settings: Using the PrusaSlicer "0.20mm NORMAL" preset, tried both with and without raft, 15% infill

Left: the mess made after the first few layers of dragging

Center: the rest of the boat was printing fine, but you can see the stepper skip in Y due to the dragging

Right: benchy printed mostly fine, but very underextruded (also not sure what the issue is with the weirdly empty layers near the roof of the boat but I assume it's related)

I'm trying to figure out what my next steps for troubleshooting might be, but Google is coming up empty for me so far. I'd appreciate any thoughts or advice you could give!