I have not had the best of luck painting PLA and stickers don't seem to last very long, so I decided to modify Ekobots-Rubik's Cube. I indented each outward facing face slightly then printed up a bunch of tiles to fit into the indents. The core is still the original file (so I didn't upload it).

This is not a "Speed" cube by any means but it is fully functional.I printed it all in PLA and used 6 M3x25 with 6 M3 washers.

UPDATE: I was having trouble with the screws backing out of the core after several twists on my original cube, so I made yet another modification. I modified the core itself with 3mm nut insets. The nuts were very tight already, but, for added assurance, I glued them in place to prevent them from moving. I also use white lithium grease to make it twist even smoother.

UPDATE #2: I was still having trouble keeping the screws from backing out while twisting the cube, so I redesigned the core from scratch (using Fusion 360). In order to make it easier to print, I cut the core in half, added fillets and made it so that 3mm square nuts can be used (this way they won't twist loose). Also, I printed the new core in PETG to give it more strength. Print 2 pieces of the RC Core v2 and then, when gluing them together, make sure that the holes line up with the cut outs. If aligned properly, you will have channels for all 6 square nuts. I also printed the new core without supports (using Slic3r) and it only required minimal cleanup on some of the overhangs and at 50% infill (.2 layers). Also used a drill bit and cleaned up the screw channels (by hand). Be careful not to over-tighten the screws. I did and I broke one of the corner pieces and side pieces (which I promptly reprinted).

Print Settings

Printer:

Anycubic Kossel Delta

Rafts:

Supports:

Yes

Resolution:

Infill:

20

Notes: