At some point in the use of my CTC 3D printer, I kept getting annoyed at how unwieldy the filament string was. It didn't matter wether the filament was ABS or PLA. If you accidentally let go of the filament string during the changing process, the filament roll would unwind badly. I thought about putting a large metal clip on the top part that is used to mount the metal guide for the print bed. Then I thought of making these babies.Just print the STL file on it's side or better yet print it upside down with the little "legs" sticking out in the air. Once printed, just like the picture mount on the top of your CTC 3D Printer on the wooden part that "mounts" the metal rods which guide your build platform. My settings when printing: Infill: 20% Shells: 2 Layer Height: .20mm Use supports if you are printing the STL as-is. I recommend turning it in Makerbot or Replicator G so that it is on it's side or upside-down with the legs sticking up (that way you do no need to print supports). You will need glue to make the installation permanent. On my printer I had to dab some on the filament guide between the stubby "legs". I often found that no matter how "snug" I made the part, the filament would eventually force it off the 3D printer unless it was glued on.