My own design of a circle 3x3x3 puzzle. Please refer to my shop home page for how to contact me if you would like stickers for this puzzle.
To assemble this puzzle, I recommend that you have a DIY core, since it will turn much better and be much easier to assemble.
For DIY cores: 1: Remove all centers from the core. 2: Begin assembling like a standard 3x3x3, but you MUST glue the centers onto the core instead of using the screws and springs. You can use the screws and springs in addition to the glue to make the core less likely to snap, but you only really need to glue it. 3: After the first layer is assembled (and that center is glued on), put in the 4 edge segments, which are composed of 3 pieces each. Glue in the 4 centers that hold them in. 4: Put the rest of the pieces (the pieces that correspond to the last layer) on top of the puzzle the way they should go. Glue on the last center. 5: Sand, sticker, and enjoy!
For Non-DIY cores: You must attempt the above instructions, but it will be very very tricky to get the glue in between the centers and the core at the right time.
NOTE: If you would like the circles on your circle 3x3x3 puzzle to rotate individually and not be fixed to the core, you don''t need to glue them.
If you have any more questions, please refer to my shop home page for contact information.