On B9 Creator use: 25 micron NZ resolution and 50 micron XY resolution.
This is printable with a standard FDM printer as well. I have included an exploded assembly view STL to show how to assemble the pieces.
I recommend setting your slicer to print at least two outlines in order from inside to outside to help with the overhangs. I printed it at .2mm layer height at 90mm/sec. It took just over 2 ½ hours to print. You will need to print 7 pins to connect the heart pieces to the center piece. I recommend printing extras just in case.
I suggest lubing the contact areas for each piece. I use CRC Heavy Duty Silicone spray to lubricate my parts. The parts will actually kind of stick while they are wet with the silicone spray, but will move freely in a couple of hours after it dries. Some cleanup may be needed around the connector holes depending on how much your printer squishes the first layer. Be careful not to clean it up too much. You do not want the holes to be too loose. You may also need to clean up a few strings depending on how well your printer handles the overhangs. Nothing an X-acto knife won’t fix.
Before assembly, notice that there are two sizes of sides on the center piece. The larger heart pieces will attach to the larger sides of the the center piece, and the smaller heart pieces will attach to the smaller sides of the center piece. I use a needle nose pliers to insert the pins into the heart pieces since they are so small. Be careful not to squeeze them too much. If they get stuck in the squeezed shape, they will not hold the heart pieces on. Use the exploded assembly view STL for reference for placement and orientation. As you add each piece, make sure that neighboring pieces are oriented correctly.
To assemble, insert the key through the hole in the bottom_w_keyhole until it is sticking out. Insert this into the hole on a large side of the center piece. Next, insert a pin into the top piece and attach it opposite the bottom piece. Add the other pieces oriented as seen in the exploded assembly view STL. After it is assembled, carefully turn it. It may take some work to get it turning well. As stated before, lubrication helps. With a little time to break it in, it will turn as easily as the one my 7 year old daughter is turning in the video.