fidget gear keychain spinner

Since some people requested it, here is a gear ring as key-chain pendant (check out my fidget gear rings). It comes in a few sizes and is prepared to be printed in multi-color, but an MMU/AMS/etc is not required. Only the top/bottom 2 layers of the small planet gears are colored, so there are only 4 filament changes, which can be done manually.

General settings:

• I use 0.4mm nozzle and 0.17mm layer height
• random seam placement
• I prefer NOT only one perimeter/wall on top layer
• concentric top infill

MultiColor with MMU/AMS/…

• Load the 3mf file
• Click yes to load as single object with multiple parts
• Change parts 3 and 4 to a different color; you can also choose 2 different colors, so top (part 4) and bottom (part 3) are different.
• set the general settings above

MultiColor without MMU/AMS/… (manual multi-color with virtual extruders)

• Expert mode
• Printers - General - Extruders: 2, 
• Printers - General - Single Extruder Multi Material: yes
• Printers - Custom G-code - Tool change G-code: M600
• Printers - Extruder 1/2 - Extruder Color: assign colors
• Print Settings - Multiple Extruders - Wipe tower - Enable: no
• Load multi-part 3mf
• Load as single object with multiple parts? Yes
• In parts list: Assign extruders to parts
• Set the general settings above
• optional: Add instances to print many
• Slice
• Check the order of filament colors in the preview
• Send to printer
• The M600 causes a manual filament change. Load new filament, grab purged filament, but don't pull it away yet, confirm color change, then another bit of filament will be purged, then pull away the purged filament.
• Unfortunately there will be an unnecessary tool-change right at the start: Either edit the G-code file and remove the first M600 line before uploading it -or- just go through with it and insert the same filament again.
• Here's the original and longer guide for this method:
  https://forum.prusa3d.com/forum/prusaslicer/manual-multicolor/

You can use the turn tool to break the ring loose and to break it in, e.g. with a power tool.

This model requires a well dialed-in printer and filament combination; depending on these and the settings, the gears may

• rotate freely and quite smoothly right from the plate
• need some force to break free
• need some minutes of breaking in to run smoothly
• be totally fused together

If you have problems with fused gears:

• use force; if it breaks it wasn't usable anyway.
• try a different filament; some (like silk) are more prone to ooze and fuse than others.
• Reduce the extrusion multiplier/flow ratio a bit
• try a slightly negative XY size compensation (e.g. -0.02)
• try reducing acceleration and speed
• try reducing the temperature

Have fun!