WATCH WINDER
This is the second version of my watch-winder.Here is the link of the first version
https://www.thingiverse.com/thing:2195223
This model is made with a 3d printed frame, and some cheap stuff.
I have use very simple electronic devices such a us a simple Arduino uno (Arduino nano too), a simple oled display a DHT-22 temperature sensor and a 5v stepper motor 28YBJ48.
Display
https://www.banggood.com/custlink/DDGDThVSIw
Temperature sensor
https://www.banggood.com/custlink/3KGm1R5SOG
Stepper motor and driver
https://www.banggood.com/custlink/vvvG7dVSoR
Bronzines(10X12x20)
https://www.banggood.com/custlink/3G3G7hP9Or
I have used a small potentiometer to turn off the watch movement while it continues to show temperature, but you can use a simple button.
I uploaded (download link at the end of the page) the Arduino sketch that I use to move the motor and control the display at the same time. ( I advice to use millis() function to make possible to work the display and motor at the same time, and use accelStepper.h library instead of stepper.h because it lets to control the motor in a half-step mode, which is more quiet and efficient.)
I used bronzines instead of radial bearing for simplicity and versatility, and i made a 2:1 gear ratio to let the motor turn easily.
I chose helical gears with a big modulus to make them more quiet.
Gear has a real involute profile made with Solidworks because toolbox uses an arc of circumference.
If you need I can give a text file with the profile points of the gears made with a matlab.
The Thingverse project where you will find stl files on this link:
https://www.thingiverse.com/thing:3779926
if you like, offer me a coffee please