Struggling to dial in perfect prints on Core One — tips?  

RE:

- Slicer - I like to mess around with the slicer settings but honestly the stock Prusa profiles work a treat for 95% of prints unless you have special cases.

- Just make sure you have the most up-to-date firmware. On mods, usually just quality of life improvements not necessarily going to improve the print quality without more invasive upgrades. My advice is just make sure the gantry is square and the belts are correctly tuned and you are primed to make great prints. 

- Filament brands - if buy cheap and you'll get a mixed bag. Can be great at times and then terrible. I think when you go with the more expensive brands (polymaker, prusament etc) you pay for a more consistent experience, sometimes not always needed or worth the price difference.

Id advise always drying your filament before use and think about how you store when not in use. You note stringing, this usually indicates the filament has taken on water. A lot of moisture will impact surface quality also. Drying before use might be all you need to do. PETG is well known for this issue. A freshly opened spool doesn't necessarily mean it'll have low moisture either, can be packaged in the factory already after taking on water. I think likely a bigger problem with more budget filaments but can be an issue with more expensive brands too. A couple hours drying will help. I print a lot of elegoo PLA and PETG for protyping or just for rough and ready prints, once well dried have had good results. When I need best quality for final prints I pull out my prusament or polymaker spools. 

On the overhangs, no printer can print in mid air so depending on the angle, a well placed support is always recommended or reorientating the print

RE: Struggling to dial in perfect prints on Core One — tips?

When I want a decent print, I go to my Mk3. 

My impression is the Core One has some teething problems not yet figured out. And I am having doubts they ever will be. I'd rate the Core One as being in the same "development stage" as the early i3 Mk3, which really wasn't finished until the Mk4 was released.  

You will also hear many here report flawless prints, but if you search for their threads you'll find they are suffering the same maladies the rest of us are seeing. So take the positives and the negatives with a grain or two of salt. Sure, certain models will print well, regardless of the printer. But try to do real things, and you are liable to fall into gaps. I still can't get a simple row of attached square boxes to print correctly. Rather hysterical, really.  In this case, it is a slicer/printer interaction; half of the issue is firmware and deceleration, half the way the slicer is broken and a setting is being misapplied to an inner perimeter rather than the outer is should be affecting so you can't compensate for the firmware issue (both have been reported to GitHub).

That said, I will never use a SPEED profile for the Core One: almost certain print disasters.  Sure, lots of plastic spits out very fast, but so far only the simplest models are even acceptable - anything with any functional detail gets lost in translation. How can you print something and get perimeters that don't join in corners? Why would you? 

Rant complete ...

RE: Struggling to dial in perfect prints on Core One — tips?

I agree with @tim. PrusaSlicer 2.9.3 SPEED and BALANCED with a 0.4mm HF nozzle on even a simple PETG print is a recipe for disaster so I don't use them. I just did a print with BALANCED and the result was comical... wish I took a photo. STRUCTURAL is perfectly clean. If I need to print something fast and I don't need detail I switch to a 0.6 or 0.8 nozzle.