This assembly was designed for raising and lowering window shades using a single stepper motor and a microcontroller. It was designed for pull cords made up of 3-5 mm beads and a 28BYJ-48 5V stepper motor.

https://www.youtube.com/shorts/Urxh3dx94WQ

The assembly consists of 5 parts:

1. 1 mount that is secured to the window frame with three screws
2. 3 gears (N10, N15, N20)
3. 1 cover that holds the pull cord in place

To complete the build:

1. Two bearings are needed: https://www.amazon.com/Pack-608-2RS-Ball-Bearing-Skateboards/dp/B07C6FL8TW/ref=sr_1_3?keywords=bearings&qid=1650076327&sr=8-3

2. 28BYJ-48 5V motor, control board, and programming instructions can be found here: https://lastminuteengineers.com/28byj48-stepper-motor-arduino-tutorial/

3. Window shades used for testing can be found here: https://www.amazon.com/gp/product/B088FD62YV/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1