Build a WINNING Belt Sander Drag Racer

Step 4 Even a Little Pulley Can Teach a Big Lesson

This pulley taught me several things:

1. It pays to take your time thinking about how tools are made and the forces that are at play. This shaft turns counter-clockwise and therefore must have left-hand threads.
2. If this one has left-hand threads then the large shaft must have a right-hand thread. Crud! So much for my first thought about simply swapping the two pulleys. Oh yeah, I'm going to use a poly-v belt so I have to replace the pulleys anyway. (I've got to get more sleep!)

You'll notice from the photo that the pulley has a recess that is needed to allow the pulley to seat in the shoulder of the shaft while leaving room for the plastic housing that restrains the bearing. My plan to replace this pulley will require either a similar recess on the replacement pulley, or perhaps a washer that can slip on the shaft and space the new pulley proud of the plastic case. Hummm. I think I'm going to sleep on that one too.