I used what stock I had available, after powering up the control board and motor, I timed the motor to one rotation every ten seconds. I needed to slow that down so i started cutting a new pulley for the threaded rod and using a rubber band as a belt (works great for dampening stepper motor vibration)I was able to get one rotation on the rod end every 42 seconds. I messed up and put the motor too close to the end bracket of the tile cutter and that cost me an inch of travel because the slide mechanism strikes the motor body. I had accounted for this earlier but forgot over a weekend. Take notes next time. So in all, I wound up with 26.5" of travel, and the 3/8" rod having 16 TPI... 26.5 x 16 = 424 revolutions per full transit of the slide. 424 x 42(seconds) = 17,808 secs. 17,808/60 = 296 minutes. 296/60 = 4.94 hours for full transit. It will go much faster for other uses but I intend to use primarily for star trails.