Multiple print problems across multiple printers. What am I doing wrong?

[CLT9er]

All right folks, I need some help with one of the most frustrating technology experiences of my life.

Purchased an A1 combo about three weeks ago. I printed a benchy and a few other small things just fine to start. When I tried a larger print though, it messed up about halfway through. From that point on, it never printed right again.

Bambu support initially said the nozzle seemed too low, and it was bumping the print. They asked that I tighten the seven screws on the hotend, and I did, but it didn’t fix anything. Support had me extrude manually, and everything looked good.

Since support was slow to respond, I wanted to make sure I didn’t miss my return window so I just chalked it up to a bad unit. I returned and purchased a new one, but it did the same thing. I got one good benchy, a test cube, and a larger print, but now it’s doing the same thing.

Sometimes it seems too low, sometimes it seems too high. Sometimes it won’t print at all from the start, it just spins around with filament attached to the nozzle, sometimes it prints but immediately messes up, sometimes it messes up partially through a print.

I’ve calibrated again and again, I’ve cleaned with Dawn and scrubbing (making sure not to touch again), I’ve changed hotends, I’ve used several different brands of filament, I tried printing at 50%, I tried heating the hotbed a few degrees, I tried using an adhesive on the hotbed, I made sure the plate and nozzle match settings, I’ve manually trammed.

Now it’s happened with two different brand new devices, I’m wondering if I just have bad luck. Is it possible two new devices were just bad out of the box?

https://drive.google.com/file/d/1yRMncKDm8eAKEnhJmCQyJituWA876m5C/view?usp=sharing

https://drive.google.com/file/d/1D0ipoczY9BgTchRATydqCiMV0T2Bpu1S/view?usp=sharing

https://drive.google.com/file/d/170KUKUipv3mzZLWEGqR4sdmPagJxYtKI/view?usp=sharing

https://drive.google.com/file/d/1AFY0umQ0mY05RZhs3AbmkiemaUtT5Z41/view?usp=sharing

[EnoTheThracian]

From the vid’s, you obviously have bed adhesion issues.

Since the A-series has a known issue with the print head screws, it is sound advise to check and, if neccessary, tighten the print head screws. However, I assume your issues may be much more basic.

While you did mention bed cleaning, I have found my new (textured) plates to require a bit of “breaking in”. Not (only) by printing. Several repeated (!) runs in the sink with plenty of warm water, dishwashing liquid and a stiff, clean (!) brush can do wonders.
Similarly, I have found moist filament to aggravate issues. It may help to dry the filament. You can do that on the printers heat bed using the cardboard box the filament came in.

Another test you can do is to increase the first layer line width. It is the modern equivalent of fiddling with z-offset as it forces a 1st layer squish. If it shows underextrusion, there may be a flow and/or z-offset issue, if it still slides off, it is a plate contamination or temp problem (heat bed and/or nozzle).

&

PS: The filament can give further hints. Which filament(s) did you use?

[CLT9er]

Appreciate the insight. It’s been a mix of basic PLA filament, - Esun, elegoo, and Inland. I’ve scrubbed the plate several times decently well. It’s just so weird to me this is happening with two different new printers. Makes me think there’s definitely something I’m doing, but I’m just printing basic files from Bambu at this point, nothing custom.

[EnoTheThracian]

Well, fdm has so many variables in play that different root causes can give similar errors. So troubleshooting can become a bit of an art. And indeed, it may just be a case of being particularly unlucky.

Nevertheless, I’d reccomend to do what I do when stumped.
First, I do all of the recommended maintenance (and belt tightening), revert all modifications to defaults, clean the plate really thoroughly (again), dry the filament (again), stick to the defaults (easier with Bambu filament as 3rd party filament needs to have recommended settings applied in the slicer (!)) and then try at a slower speed.
Usually, this allows me to diagnose the issue better by spotting peculiarities during printing, helping me to rule out particular root causes.

If the first layer still does not stick and there has been no play to the print head, I’d try increasing the line width by 50% to help with the diagnosis.

&

[RafaelSantos]

I am facing a similar problem with an A1 with 800 hours of usage. The first layer adheres to the plate, but it is very stringy! It happens with all my filaments (from a Brazilian maker, never had problems before), I just recalibrated and cleaned the plate.

It seems that the extruder flow is not enough and it is printing thin, messy squiggly lines.

Any suggestions on next steps to try?

thanks

This is part of the 1st layer (with the printer running).

When it starts to print the second layer it appears a bit better.

This is the final printed piece, still ragged.

And the last (+Z) layer: