Watch Winder MK2:
Main Features:
OLED Display with TPD (Turns Per Day)
Rotary Encoder with Push Button for selecting TPD setting
Upgraded to NEMA stepper motor
Cooling Fan
Spring loaded bearings
Watch Winder MK2:
The first Watch Winder I designed was 4 years ago when I was 20-21. I have been thinking about improving the design for a very, very long time. Now that I have 4-5 years more experience with building and electronics, I felt confident that I could design and create an even better watch winder.
MK2 aims to add more features to the original watch winder while being better designed, but still maintaining the beautiful aesthetics of the 1st version.
The important thing to keep in mind is wiring the coils correctly. They need to match each other. The example Stepper Motor Driver is an A4988. (How To Mechatronics - Stepper Motors and Arduino - The Ultimate Guide)
TMC2208 Stepper Motor Driver:
I decided to use the TMC2208 Stepper Motor Driver for this project as it is very quiet - much quieter than the A4988 and DRV8825 - and has the option for microstepping.
GND - Ground
VIO - Logic Supply Voltage
M2B Motor Coil 2
M2A Motor Coil 2
M1A Motor Coil 1
M1B Motor Coil 1
VM - Motor Supply Voltage
DIR - Direction Signal Input
STEP - Step Signal Input
CLK - Clock Input
PDN - UART and Auto Power Down Control: GND = On, VIO = Off
MS2 = Step Configuration
MS1 = Step Configuration
EN = Enable Motor Outputs: GND = On (0V), VIO = Off (5V)
TMC2208 Specs and Important Information: (from fysetc website)
Logic Input Voltage (VIO): 3 - 5V
Motor supply Input Voltage (VM): 5.5 - 36V
Potentiometer is for adjusting motor current input (adjusts the resistance):
Max Continuous Motor Current Output: 1.4A, Peak Current: 2A. Reference Voltage should not exceed 1V.
Measure the voltage on the Vref pin (0 - 2.5V). Maximum settable motor current is 1.77A RMS. SilentStepSticks can only go up to 1.2A RMS
Definitions:
Irms: Root Mean Square current per phase (lrms = Imax/1.41)
Imax: Maximum current per phase (Imax = lrms*1.41)
Vref: Voltage on the Vref pin
Equations:
Irms = (Vref*1.77A)/2.5V = Vref*0.71
Vref = (Irms*2.5V)/1.77A = Irms*1.41 = Imax
Note: IMPORTANT
Vref measures Gnd and the voltage at the middle of the potentiometer.
Do not connect the motor when measuring the voltage, otherwise it is easy to burn the driver.
Power should be connected when measuring voltage, do not just connect USB power supply.
Resources:
The Machine Shop - Website
https://themachineshop.uk/how-to-drive-a-nema17-stepper-motor-with-a-tmc2208-v3-and-an-arduino-uno/
Motor Wiring is incorrect - I followed HowToMechatronics to get the Stepper Motor wired correctly. It would still be useful to use a multimeter to figure out the coils.
Used their code for Stepper Motor movement
How To Mechatronics - YouTube
https://www.youtube.com/watch?v=7spK_BkMJys&t=1073s
Used the A4988 Wiring Diagram in the video
TMC2208 Pinout Diagram
https://wiki.fysetc.com/docs/TMC2208
Diagram of TMC2208 Stepper Motor Driver Pinout. Good information about the TMC2208