This is a molecule kit which includes large atoms with 6 holes, small atoms with 1 hole, and rods to link them. For the atoms (The 1st and 2nd files), I used PLA. For the rods (The 3rd file), I used TPU. Print the atoms with one of the holes down, and print the rods horizontally. In the print info below, I stated that it doesn't matter if you use a raft, but I used a brim for all of the files and it worked great. Therefore, I'd recommend that you use a brim. This is my first Thingiverse post, so let me know if there's anything I should add in future posts. I hope you enjoy!