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. 

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

Hi I just received mine and not able to print because of huge layer shifting Even all tests are ok. My printer must go back for services and i have not printed anything yet. In the past prusa was making a print Before sending out a printer. 😖

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

Initially I was sometimes getting layer shifts as a result of the print head colliding with blobs of filament on the print.

What solved it for me was properly calibrating the Z offset and setting this in the slicer. (This isn't part of the basic calibration that the built in wizard leads you through).

I used the live Z adjustment to find the value that gave the best first layer. (To get into live Z adjust, once the print starts go to tune and hold the button do down). I used a test pattern like this one:

https://www.printables.com/model/251587-stress-free-first-layer-calibration-in-less-than-5

...to determine the optimum Z offset, then set this in the slicer. (Try a different Z offset for each notch).

After doing that, so far, I've been having trouble free printing. I've also added a filament dryer and I think this might have helped to reduce stringing a bit (but not a massive difference). There may still be minor VFAs where there are sharp features on the perimeter (likely true of any 3D printer) but these are not an issue for me at all.

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

Regarding:   "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 am a  "newbie" so perhaps I have no idea what to expect or what to look for.   This is my first two weeks or ever owning and using a 3D printer.  I have printed maybe 10 items, half PLA and half PETG.   Without knowing any better, I used the default PrusaSlicer 2.9.3 setting of SPEED.   It has the .4 HF nozzle.   All the prints look great.   But...  I had done a LOT of reading before getting the printer.  So right when receiving it, I dried my filament for 4 hours before printing.  Both PLA and PETG.   Works great.

What should I be looking for?  I don't see zits, oozing, or stringing.  The surfaces look clean, but again I am a beginner.

Cheers,

Neal

RE:

One of my own "lessons learned": The Core one has no means of controlling the three Z-axis motors individually, they are wired together (logically). 

Instead, it whacks the table into the end stops to sync the motors. Which is ... ummm... fairly accurate (enter Cosmo The "Fairly Accurate" Knife Thrower). Theoretically the error gets fixed in software. In real life it's always better if there is no error in the first place. 

So take some calipers (typical digital ones give readings with 10 µm accuracy which is far and beyond the level of consistency between mechanical end stops, at least without "user intervention"). Measure the height (at any convenient level) to the gantry and manually tweak the screws to make it as level as you can get it. Then cross fingers the printer won't "forget" the setting stored in "mechanical memory" (which it won't unless someone carelessly runs Z-axis calibration).

If in doubt, print a first layer test = a very thin box spanning the print bed.

And don't get me wrong, the software correction is probably as good as you can make it. But, common sense prefers "no significant error that would require software correction".

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

Posted by: @neal-2

Regarding:   "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 am a  "newbie" so perhaps I have no idea what to expect or what to look for.   This is my first two weeks or ever owning and using a 3D printer.  I have printed maybe 10 items, half PLA and half PETG.   Without knowing any better, I used the default PrusaSlicer 2.9.3 setting of SPEED.   It has the .4 HF nozzle.   All the prints look great.   But...  I had done a LOT of reading before getting the printer.  So right when receiving it, I dried my filament for 4 hours before printing.  Both PLA and PETG.   Works great.

What should I be looking for?  I don't see zits, oozing, or stringing.  The surfaces look clean, but again I am a beginner.

Cheers,

Neal

 

Really depends on a lot of factors starting with the type of filament, the brand and more crucially how dry it is. If you live in a humid environment then it's a necessity to keep your filament in a dry box and occasionally run it for 6-8 hrs in a filament dryer. If you live in a dry environment like I do then it's less of an issue. Damp filament can cause all sorts of issues. Zits, bad layers, stringing, rough surfaces and nozzle clogging are all indicative of damp filament that needs to be dried. If you pull fresh filament out of a vacuum bag and use it for a couple of weeks you won't notice any of this. Using the faster profiles like "Speed" for example can make this worse. 

I would say in general though the speed and balanced are fine to use as long as you are creating functional parts or prototypes and can accept some stringing, not perfect corners etc. 

RE:

mine prints great now, it took a bit of calibrating and messing around with some things but here is what I did.

- make sure your gantry is square (prusa has some guides on it if you go down there belt tuning tutorials)
- Tune the belts after to the correct frequency, mine i had to retune 2-3 maybe more times over the course of several days / prints, they seem to stretch a bit, just check them ocasionally. Mine are perfectly dialed in to the values prusa tells you in their tuning page on the prusa app.
- Use infill like gyroid, i noticed some prints would get wobbled around by the print head hitting infills on cubic (and it will be worse on grid), make sure to use infills that dont "cross" themselves, (like gyroid)

Otherwise, I didnt change hardly any settings over prusa's defaults that I think would really matter. I tend to use balanced exclusively and my VFAs are really cleaned up now. It prints like my old MK4 but faster.