• No Supports.
• Print-in-Place.
• Very Durable. 
  • They've been thrown on the floor many times with only two breaks. 
• Captive 608 Bearing (same size bearing as in a skateboard wheel).
• Captive Ø8x5mm Magnets (or Ø8x2mm + Ø8x3mm stacked).
  • Bearings and magnets are captive to prevent choking hazards in case of part failure.
    • If you manage to break it, the center hub presents the greatest risk with a diameter of 19mm (.748") and thickness of 5mm (.197").
• Designed to work on refrigerators with both flat or convex door panels.
• Small, Medium, and Large gears.
  • Small gear requires Qty (1) bearing and Qty (2) magnets.
  • Medium gear requires Qty (1) bearing and Qty (3) magnets.
  • Large gear requires Qty (1) bearing and Qty (5) magnets.
• Colored by layer to minimize color changes.

About:

I'm super pleased with how well these work!  The embedded bearings make them so satisfying to spin.  You can certainly use printed bearings… but I'd recommend using real bearings so they spin like butter.👌  My son (1 year old) plays with them for minutes at a time; gets bored; terrorizes the kitchen; then remembers the colorful spinning gears and runs (while yelling) back over to them.  

UPDATE: It's now been two weeks and he's still entertained with them!  Anyone who has a toddler can confirm that's a big deal.😉

COMING SOON: SNACK Dispenser add-on. See video below:

Note that there are a couple snacks under the fridge; I'm working on a solution to eject the snack out away from the fridge. 

I'll upload once that's resolved.

Instructions and Tips:

Each gear is divided into two objects: gear and spindle.  The spindle has a Honeycomb infill with 30% density and 4 walls; the gear has Adaptive Cubic with 9% density and 2 walls. 

Shown in the following image, I have it set to pause at layer 65 (assuming 0.2mm layer height) to press in a 608 bearing; support the print bed from the underside while pressing the bearing from the top (wear a glove if needed).

It will pause again at layer 101 to drop in magnets.  Depending on how snug the magnets fit, I recommend putting a drop of glue in the hole and let it set up before continuing the print (hardened steel nozzle pulls magnets out if they aren't good and snug.

It will pause again at layer 102; this is your opportunity to stop the print if your magnets are weak or if you plan to coat the bottom with any sort of fridge-protecting layer.

I've included “Pry Pockets” to make it easier to break the gear and spindle apart (see following images).  Work your way around and loosen it a bit at a time.

On a couple of them I had to use a scraper and carefully work it in toward the bearing.

I would next recommend slipping some sandpaper between the spindle base and the gear to smooth it up.  Place the smooth side against the back of the gear and hold it there; then rotate the spindle while pressing the spindle base against the gritty side of the sandpaper.

Note that the Small gear is “undercut” in order to interface with Medium and Large gears; here's a closeup:

Feedback is always welcome! 

ENJOY!