High Speed Linear Actuator Proto
This is a prototype of a high speed linear actuator for my project. The actuator has ~20cm stroke and it uses a micro DC motor in a pulley wheel setup to quickly move the pin forward and backward.
The pulley wheel string is made half of rubber string and half of resistor wire (cauge 40 NiChrome) for motor controller to know the exact pin position. The resistor wire can detect the position in ~1mm precision with the 12-bit analog input of Arduino Uno. This sensor is necessary because DC motor and pulley wheel setup can't alone set the pin position precisely, so the sensor feedback can be used to rotate the motor the right way to move the pin to the exact position.
I made an H-bridge motor driver for the actuator using 4 NPN transistors (PN2222A) and another one with L293D but both of these drivers lost too much voltage to drive the motor properly. I'm still looking for a solution for the driver to test the actuator positioning. In the video I just swap the motor voltage direction manually to move the actuator back and forth to test the mechanism.