Design

Originally, I was thinking how cool would it be to have a flexi snake, but each body part was a gear. 

The result was a half link like chain, where each joint had 3 axis of rotation.

Gears

Each gear is able to rotate independently, and mesh with it's neighboring gears. A normal gear would not work in this situation because of the degrees of freedom. I had to come up with something custom, and thus the pumpkin gear.

Vertical Pivot

Each gear and link can pivot on the vertical axis with 70 degrees of freedom.

Horizontal Rotation

Each pivot can also rotate on the horizontal axis with 230 degrees of freedom.

Slicing

⚙ Basics

I recommend a 0.18 layer height for this print, with bridge setting enabled.  I used PLA+ for my prints.

⤴ Supports

For slicing this does require supports, but only the gears require them.  The links do not. 

For Prusa Slicer disable automatic supports. Then go to Paint on Supports, select Smart Fill, and change the smart fill angle to 20 degrees.  Finally select the bottom of all 12 of the gears.

Additionally I recommend using Organic supports with a Maximum Branch Angle of 50.

↔ Tolerance

I set the majority of tolerances are set to 0.3mm to make it more universally printable. If your printer is able to print tighter tolerances you can change you X/Y Size Compensation (Prusa Slicer > Print Settings > Advanced > Slicing >X/Y Size Compensation). Also, scaling this down to 66.6% will change the tolerance to 0.2mm tolerance.

↗ Scaling

If you wish to scale this, you will need to keep the tolerance.  This model comes with a conservative tolerance of 0.3mm.  If you scale this to 2x, the tolerance will scale to 0.6mm, to compensate for this change your X/Y Size Compensation to 0.3mm which will remove 0.3mm tolerance ((0.3mm x 2) - 3mm).  For 50% scale, you should change your X/Y Size Compensation to -0.15mm ((0.3mm / 2) + 0.15mm).

Printing

Here is my first completed print.