While Trish is completely right that the roughness can't be completely eliminated (you can't print a perfect spherical surface with discrete layers), the situation can be improved dramatically. The most telling photo in your question is the one of the removed support structure.
The part of your sphere that's seriously rough is all severe overhang. In this ...
Huh. On a hunch I just changed a copy of a .3mf model to have a .zip file extension, and what do you know, it works! 3mf is just a set of compressed xml.
The zip folder structure I saw included a MetaData folder. I bet you could put just about anything you wanted in there, as long as it doesn't conflict with things other 3mf parsers are expecting to find.
The problem lies in Fusion 360.
If you export using file export as .3mf then the refinement (poly count) is set to low. Thus it creates a low-quality circle.
If you export through the mesh tab, select 32d print and make sure the refinement is high then it exports a nice-looking perfect circle.
Yes you can!
To have stronger prints you would have to choose the correct direction of filament deposition paths/traces. This answer demonstrates changing the direction of the filament path in Ultimaker Cura slicer.
To do this, it requires some tinkering of your model and choosing the correct slicer parameters (decimals aren't allowed in changing the ...
Layer shifting has two basic causes: the partially printed part moves or flexes, or the bed or Y carriage (almost always -- they seem rather uncommon on the X axis) skips one or more steps in one direction or the other.
Permanent layer shifts -- that is, where the entire print above the shift is and remains shifted -- are more likely to be the latter; ...
Regardless of the choice of long bridge support or short bridge support, Prusa Slicer 2.3.0 has a feature which allows forced support or allows forced no support.
In Advanced or Expert mode, there is an icon in the left tool bar for "paint-on" supports. The left mouse button paints on supports, while the right mouse ...
Open PrusaSlicer, go to Configuration -> Configuration wizard, then go to page named "Other Vendors", tick the checkbox next to the name "Creality", then click "Next" at the bottom right of the window. A page with a handful of Creality printers should appear including Ender 3. Tick the checkbox under Creality Ender 3. Then ...
You can't print them smooth
The short answer is: with FDM you can't make curves that go into the Z-direction. The better question is: Why?
Let's look at why it is rough: the roughness is from the layer height and the thickness of the perimeters (walls). At some point, perimeters of the given thickness have to be placed in a way that does not cover up fully ...
Basically all slicers work very similarly, it is a matter of preference, being accustomed, or wanting to use a certain (set of) features. Their job is to prepare the object to be sliced in layers to be executed by the printer you use. For every slicer to work properly, you need to configure the printer settings correctly.
Basically, all slicers have the ...
This may be due to uneven cooling. The part cooling fan only comes from one direction on the Ender 3 series of printers. You may be able to solve the issue by printing the walls from the outside in. If not, I recommend printing a fan shroud that has part cooling ducts on both sides; there are plenty of them on thingiverse.
In my experience, the ends of bridges must always be supported by the layer below them — not the perimeter of the same layer. Add a feature to your model which makes the area under the end of the bridge solid, not a gap.
If on even layers, the routing is in one direction and on odd layers, the routing is the opposite diagonal, you'll have a much weaker structure, as there will be no material after the crossing point.
Addressing that aspect, one could consider that the design is implemented in such a way that the nozzle creates the odd layer continuously from one corner to ...
What you're looking for is the Support Interface Layers.
In PrusaSlicer, enable Advanced or Expert mode, and under Print Settings ▶ Support Material ▶ Options for support material and raft you can decrease the Interface Layers to zero, and only the support structure will remain.
Keep in mind, this will affect ALL supports in the model, however.
What I have done:
Using lowest hotend temperature 170 °C
Using highest hotend temperature 220 °C
No wobble in extruder (x-axis)
No wobble in gantry (x-axis)
No wobble in bed (y-axis)
No wobble in z-rod (z-axis)
Bed levelling to my perfect
Shorten and slower the retraction, from 8 mm and 70 mm/s to 6 mm and 50 mm/s
Enabling and disabling retraction
These are (at least almost certainly) not layer shifts. A layer shift is when the physical toolhead position becomes inconsistent with the logical one because a stepper motor missed a step or the bed surface shifted or something else went wrong. It's possible for them to reverse if the same happens in the opposite direction at a later layer, but very ...
Zeiss Ikon's answer is good - but just in case that doesn't solve it, have you printed larger / longer prints before? There's a well known problem with the Ender 3's 4.2.2 motherboard that causes layer shifts as it overheats on longer prints. You can try elevating the printer and putting a fan underneath to see if that changes anything. (I had that problem ...
It doesn't seem to be heat creep. See What are ways to avoid heat creep?
Have you measured the actually temperature of the heater block? You may have a failing sensor (thermistor) or sensor circuitry. Optically is the best way to measure. The least expensive way is with multimeters that come with a temperature sensor, such as a thermocouple (lowest cost ...
Still don't have an actual answer as to why repairing the stl file didn't seem to work, but since my stl file was a combination of different stl files I tried repairing the individual stl files before combining them, which resolved the problem.
Do the two loose pieces go where the fill shows up on the larger piece? If so, you may have internal surfaces there that need deleting in your drawing so that they don't mess up your slice program. Otherwise, the slice program may leave a gap in the gcode where you have no extrusion.
If you retract too much, it can cause the filament to jam in the hotend, ...
The error message explains that you cannot print your objects sequentially as they are too tall for the gantry to go back to the bed level after the first object.
In other words, your clearance between bed and gantry is too small.
Minimum Travel after Retraction is exactly what it says on the tin: if the travel after a retraction would be less than 2 mm, it does not retract. You'll want that to be short, but not 0, because retraction can lead to under extrusion at the start of a new line, and every swap from one shell to the next shell right next to it is classed as travel.
As a software developer and 3D printing enthousiast I can tell you that indeed, like Trish said, the limit is your memory (RAM) and loading/slicing time depends on the cpu power.
RAM: keep an eye on the memory usage in the task manager/performance/memory tab. When it reaches the top of the graph, the application will suddenly crash and disappear.
CPU: The ...
This is most likely a hardware problem, namely the heat bed thermistor cable.
To confirm this as the root cause, here's what you can try
Reboot the printer
Move the y axis around to make sure there is freedom of movement at both ends
Jigger the thermistor cable around in multiple directions at multiple points on the cable
If you hit BED MINTEMP or ...
The bed minimum temperature is defined in your configuration file, e.g.:
#define BED_MINTEMP 5
If the error is displayed, it means that the measured temperature drops below this level.
What I am noticing is that upon finishing the first print
This could hint to a faulty heatbed connector where the connection is lost because the bed moves to the end ...