I created this to automate my window blinds. the 180 that the servo alone would travel was not enough so I created a gearbox. When printing flip the gearbox 90 so that the flat side with the two holes is on your build plate.
This slides directly into the end of the window blinds and replaces the rod to rotate the blinds.
Feb-3-2017 I have updated a variation which should work for older blinds with the rotation rod centered down the length of the blind. It needs a bit more tweaking to work if you want to slide the mechanism to the middle of the blind, it should work well though on the end as a cartridge.
Offset_Geared_Servo_Blinds.stl works on my newer blinds.
Centered_Geareed_Servo_Blinds.stl works on my older blinds.
Please see my thread over at SmartThings.
Code for the Arduino/ESP8266 is here: https://github.com/jetpuf/SmartBlinds
I used enough layers to connect the servo screw holes to the outside of the case. I think 4 layers... or 1.6mm using a .4mm nozzle. Flip the gearbox 90* so the flat side with two holes is on your build plate.