Knocking noise on Jet 1220 12”x20” wood lathe

Trouble shooting can be a little like a Sherlock Holmes mystery, and sometimes it’s just dumb luck. Knowing you have a problem and knowing that it can be fixed gives yourself an advantage.  I see a lot of turning videos online and some of the older lathe have this knocking sound. When this knocking sound started on my lathe, I started to dig in and find a solution. And it turns out on my lathe , all you have to do is tighten a set screw on the top pulley. This set screw requires a 3mm Allen wrench.   If it continues to come back in the future, use a drop of lock-tight or add another set screw behind this one so it will not back up on you. I have included a video to help show how to fix this and what the sound difference is. Warning! It is a good idea to unplug the lathe while tightening the screw.