Inspired by Ikeda Yosuke's open/close sign design which relies on gravity and relatively frictionless joints, I decided to design one using planetary gears to drive the movement of the letters. An animation of the transition can be seen here: [https://youtu.be/TmrUlpgojlY](https://youtu.be/TmrUlpgojlY)

The gears are made to snap fit onto their respective axles, tolerances for rotational and press fit parts have been confirmed and should work well with a properly calibrated printer.

Updated 24/3/17:

• D in "closed" has finally been added to the design. Using the joiner.stl piece, the letter d should lay perfectly over the top of the c and the l. First glue the joiner to your gear_right in the correct position and then glue it to your letter d to allow proper alignment.
• Type has been refined a little bit, particularly on the letters e, d, c, and l.

Updated 11/2/17:

• Registration points added for letters to attach to gears
  Split base plate for smaller build platforms (minimum build size required 160 x 160 mm)
• Refined font to remove sharp edges
  E and S/N has been chamfered on the bottom edge to avoid catching
• Planet gears and gear_left have been heightened by 1mm in order avoid contact with the axle
  gear_left has modified gears to only allow rotation in the direction such that letters don't touch each other.