Building a linear mechanism got me learn a lot of the knowledge of using motors and relevant parts, and for getting a precise linear motion, I have to be really careful with all the lines and placements.
I started with using brass wood to build the base of the installation, one part for the rails and one part for the stepper motor. (One thing to mention I used a sheet of acrylic at the button for making it more steady).
As seen in the pictures, I drilled holes for the screws in order to fastened the base together.
After I have set up the base, I drilled another 4 holes for the L bracket that holds the stepper motor.
After the motor part is finished, I measured the diameter of the shaft that I am going use and laser cut the shaft holders with the measurement.
I did the aligning and measuring after I got the shaft holders in order to place the shafts in the right positions.
As the middle one is set up with the stepper motor, it got easier to finish the rest of the twos. So I placed the rest of the two shaft holders next to the middle one, and finished it by inserting the shafts in.
I hot glued them on the wooden base, and they are firmly sticked to it.
Final look of the linear actuator.