HO Scale TurnTable

HO scale turntable.

Parts:
28BYJ-48 stepper motor
Longrunner A4988 motor controller
Raspberry pi
screws
1/4" ball bearings
Adafruit 736 Slip Ring with Flange, 22 mm Diameter, 6 Wire

The bowl has a diameter of 323mm. The longrunner says it needs 8 volts to operate but seems to work fine with 5.5V as the stepper motor I have is a 5V. You can get a 12V version if you wish. You will need to research how to connect a longrunner a4988 to the 28BY-J-48 stepper motor. Modifications to the motor are needed to make it bipolar instead of unipolar. The Raspberry pi controls the motor by sending pulses to the longrunner motor controller. An on-off-on switch on the pi controls the direction of the rail bed. I had to put 0.1uf capacitors across the switch contacts to de-bounce them. Or you could control it with a joystick. I chose the yaw axis on a flight stick.

I added a sigmoid curve equation for smooth movement on ramp up and ramp down acceleration. Currently only active