3DPrinting

If you haven't tuned stuff yet, I'd start here. It's a great guide to tuning a lot of things

If those 2 are from the same job its either a sagging gantry on an ender or the bed/mesh is not tilted properly or not meshed/leveled properly. Check squareness and sagging gantry, then check mesh/level after.

This is going to sound stupid, but don't forget to activate bed levelling after performing the leveling measurements. Maybe this is a stupid idea but I put M29 L1 and M29 A at the start of my gcode to load the ubl slot 1 mesh and activate it. Before getting ubl I used M420 S.

I spent way too much time frustrated by bad prints before I learned that leveling wasn't active.

I thought I’d add that it looks like it’s overextruded. So much that the filament is being “pushed” out and curling back around the nozzle.

It could be the e steps, flow rate, etc but it could also be that your Z offset needs to be adjusted back away a smidge.

That could be part of the inconsistent print since the tool head movement over one section of the bed vs another may be affected by the layer below based on how the filament curled there.

If you want to do a deep dive into adjusting/calibrating the Ender I did write up a bit here (although that post does relate to Klipper and I mention settings/adjustments for Klipper it starts purely with the physical printer itself and builds on it)

https://lemmy.world/comment/7904011

Others have mentioned, but looks like 1st z is too low and it's squishing the lines together on that top right widget.

If there's a corner of the bed that's a little higher that could be doing it. The touch is supposed to ameliorate leveling, but I would check the mesh and see if it is crazy bad

How old is your Bowden tube? Could you be getting more friction when it is bent certain ways leading to inconsistent feeding?

Stop buying enders.

Almost every issue in this board is an ender.

Belt tension should be tight enough that you can strum it and hear a tone. It's possible to tighten a belt TOO much, which causes extra stress on the motors. This would result in the motors being physically very hot. However if these were both printed at the same time, that wouldn't be the issue here.

I wonder, how level is your bed? Yes yes, you have a bltouch and all that, but you still need to manually get your bed relatively level. Were these two prints next to each other or on opposite sides of the bed? How did the other prints in the same batch compare (like was there an obvious pattern of failure from one side to the other)? The bad print looks to me like the nozzle is too close, so it might be interesting to see what your first layer looks like in a test across the bed.

Even in the good print there's some blobbing at the end of each path and the main surface should be the same height as the walls around the cutouts. Did you calibrate your E-steps? It kinda looks like you're pushing out a little too much filament. depending on your slicer options, you may also check acceleration to slow down the head at the end of each path, which can help give the whole path a more uniform output.

One other consideration, although not as likely... Warm up the bed and check to see if all areas feel like they're about the same temperature. If part of the heating element went bad then maybe you're over-heating one part to compensate for a lack of heat on the rest of the bed. I only mention this because the bad print looks like it has a slant to it, but that could be an illusion of the photo.

What kind of bed do you have? If your bed isn't flat this can happen as well. I scrapped a magnetic PEI sheet because it was never gonna be flat enough for a whole smooth first layer for me