Marble Track Keychain

Features:

• beautiful keychain with interesting shape based on a Moebius ring
• nice to watch the different parts join in mid-air during the print
• illustrates that 3d prints can be combined with other objects
• useful as everyone has some key laying around that can use a keychain
• fun little gadget with the spinning marble
• ideal to show-off your printer to a friend and let him/her keep the print as a gift

See the spinning marble in action:

I'm interested in seeing what creative combinations of marbles and filament colors you can come up with. So post a picture of your creation, if you print one.

Print instructions

I have put two versions for different marble sizes: 13 mm (white marble in pictures) and 16 mm (orange-red marble). I prefer the smaller version for use as a keychain. But since many marbles have a larger diameter, I included a bigger version also. 

• Optimized for 0.20mm SPEED profile (PLA)
• Print upright with keyring hole at the top
• Supports: For support enforcers only 
• Add a support enforcer box at the bottom to keep the print stable.
• Vertical shells: 4 perimeters
• Detect bridging parameters: On
• Insert a “Pause Print” g-code above point where two halves join to insert marble.

Small loops may occur near the top overhang. These can easily be removed with your finger nails:

NOTE: If you want scale the design to fit a different marble size, try to select a scaling factor that has as little overhang as possible on the layer before the bridge that joins the two halves together in the middle: