TL;DR

Very esthetic spheric bowl with a print in place rotating outer ring.

rotating rings

I'm fascinated by print in place rotating ring stuff. 
From finger rings to fidget spinners over ring toys to bowls and spheres. 

how to slice / print

Import the 3mf file into your slicer of choice and hit slice, that's all.

Tolerances

I designed this model to be printable with 0.4/0.6/0.8 mm nozzle on less well calibrated printers with cheap filament. So this one will print fine on your printer no matter the brand or the nozzle or filament you are using. 

At least make sure your Z layer is calibrated well.

Stress Free First Layer calibration in less than 5 Minutes to perfection by yahbluez | Download free STL model | Printables.com

Scaling

Scaling up to get bigger bowls will work in any cases, 
scaling down needs a well calibrated printer.

That is because scaling up increases the tolerance while scaling down decreases the tolerance. 

Can I sell copies of this?

Yes! This project was shared under the GNU GPL v3.0 license. 
This license allows selling copies, 
but you must provide proper attribution, 
as detailed in the license itself. 
Just link to this model page.