this post was submitted on 30 Sep 2024
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Could use some help. (lemmy.world)
submitted 2 months ago by fubbernuckin to c/3dprinting
22 comments fedilink hide all child comments
 

So I'm trying to get my printer to a point where i can pretty consistently turn out high quality prints, but I'm at a point now where i get results like this. These two prints are from the same batch, same print job, and I'm completely clueless on how to fix it. I have an ender 3 v2 with a bltouch, I've adjusted the eccentric nuts, tightened the belts until the tips of my thumb and index finger couldn't tighten them any further, bed is level, using hatchbox pla. I know i can do ironing to fix the cosmetic problem, but I'd prefer to fix the root issue if possible.

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[–] SzethFriendOfNimi 9 points 2 months ago* (last edited 2 months ago) (1 children)

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

[–] fubbernuckin 5 points 2 months ago

Ah, thank you for the advice and the link!

[–] mvirts 6 points 2 months ago (1 children)

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.

[–] fubbernuckin 3 points 2 months ago (1 children)

I figured there might be something like this that i hadn't seen. I'll look into it tomorrow, i get the feeling this would cause the inconsistency.

[–] [email protected] 2 points 2 months ago (1 children)

Not sure how it works with your printer, but with mine on Klipper, after bed leveling I have to save and restart the firmware, and then I have to go back and select the profile that I just saved, otherwise it doesn't use it.

[–] mvirts 1 points 2 months ago

That ain't right 😹

Maybe try contacting klipper people https://github.com/Klipper3d/klipper/blob/master/docs/Contact.md

Or file an issue if you think it's a bug.

[–] [email protected] 5 points 2 months ago

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.

[–] [email protected] 5 points 2 months ago (1 children)

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

[–] fubbernuckin 1 points 2 months ago

Wow, this is an incredible guide thanks for showing me

[–] [email protected] 4 points 2 months ago (1 children)

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.

[–] fubbernuckin 2 points 2 months ago (1 children)

I have a glass bed and I'm using the tramming function with the mriscoc firmware to give me depth readings for each of the four screws, and I usually reign them in to about 0.04mm range. Parts close to each other tend to have similar but not the same results, and i think the patches are too small to be from bed leveling, usually only a couple centimeters.

I can redo esteps, i can see what you mean about the overextrusion. I only set my esteps to the number recommended by the manufacturer of my extruder, but i haven't measured it myself yet, maybe that's a bit silly of me. Though if that's the problem then I'm still curious why it's different in different areas.

I can check out acceleration too, i looked up what acceleration and jerk meant at one point but it didn't make much sense to me at the time.

[–] [email protected] 3 points 2 months ago (1 children)

Yeah that's a pretty tight range for the bed leveling, shouldn't be causing any issues then. OK another possibility here... the failing prints, are they on the left side, right side, one specific corner, or does it tend to move around between prints?

E-steps varies per extruder, not per manufacturer. What they recommend will get you close but there will always be some variance. On my printer Creality recommended a setting of 93 but my measurements put me up around 98, so quite a difference. Are you still using a bowden tube style extruder or did you upgrade to a direct drive? And is your filament spool mounted on top of the printer (if so, what guides have you added for the filament path), or did you move it off to the side?

Erg sorry, jerk is probably what you're looking for here. It's been awhile since I did much printing so I keep confusing the terms.

[–] fubbernuckin 2 points 2 months ago (1 children)

The falling prints i think have issues in the same spots, there are relatively small patches around the print surface that don't print very well, though they don't seem to correspond to the bed leveling screws or anything. Now that i say that I'll have to check that I'm using the mesh level correctly when i get home.

I'm still using a Bowden type extruder. The extruder itself is a generic aluminum one. My filament is run out of a sunlu dryer by the side of the machine.

I think i actually raised the jerk at one point to reduce the radius on corners, so i can bring that back down again and experiment with acceleration.

[–] [email protected] 1 points 2 months ago

Hmm I'm out of ideas then, sorry. Still wouldn't hurt to do a single-layer test print (there are various models that put squares all around the bed) just to see how that's looking. If the issue had been confined to one side or one corner it might have been a mechanical issue, but random areas makes it a lot harder to figure out.

If I remember right, jerk settings should be rather small, like single-digits, but I think calibrating your e-steps will go a lot further for cleaning up the prints.

One other step (and of course I cannot remember what this is called) is related to calibrating the filament 'pressure' along each path. It takes a bit of work to set up but the goal is to create a profile so you get a perfectly consistent amount of filament extruded through the entire length of a path, which compensates for excess amounts at the beginning and end of each path, or too little extrusion through the middle. You might even have to compile your own firmware to enable it if there's not an option in Marlin to turn it on from the software (I was compiling my own anyway for a DIY direct-drive extruder), but it really does make a difference and it's a set-and-forget thing that you only really need to do once.

[–] mrcleanup 2 points 2 months ago

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

[–] half_built_pyramids 2 points 2 months ago

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_do_I_computah 2 points 2 months ago (1 children)

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

[–] [email protected] 2 points 2 months ago (1 children)

Creality bases are notoriously NOT flat although I've heard their quality has improved over the years. I have one of the 1st-gen Ender 3 Pro machines with a terrible dip in the aluminum base. One nice thing about a thicker bed material is that you can use discs of aluminum foil the shim the base. I started with a glass bed and 13 layers of foil to get the glass reasonably flat. I have since moved to 3mm G10 with a PEI sticker which is working pretty well (in case you want to try PEI again). I found some scrap G10 material on ebay and chopped it with a table saw, sanded all the edges, then got a PEI sheet that was 10mm wider than my bed to allow for some slop. Putting down the stickers is a lot easier if you have someone helping you. Then trim the overhang and you're ready to go.

[–] Dkarma -2 points 2 months ago (1 children)

Jesus Christ just throw it away and buy a real printer.

[–] [email protected] 4 points 2 months ago

Sorry, just because you're not capable enough to work with something that wasn't completely fine-tuned for you at the factory doesn't mean many of the rest of us have any problems with these machines. I do manual bed leveling and I can walk away from my printer for a year, turn it on, and pop out as good of print as the previous time it was used. How well does your "real" printer work after a year of neglect and with all the fancy gizmos turned off?

[–] Dkarma -1 points 2 months ago (1 children)

Stop buying enders.

Almost every issue in this board is an ender.

[–] fubbernuckin 3 points 2 months ago

I have never bought an ender. I just happen to have one :P