Not sure if you did this already. Put the RPM ball cup in a drill. Just tighten the chuck on the drill enough to hold the ball cup and keep the drill chuck from spinning on the ball cup. Then dab a little bit of grease or Chapstick on the treads of your turnbuckle. Hold the turnbuckle and use the drill to run the ball cup in and out on the threads of the turnbuckle a couple of times. It will make it a lot easier to adjust the turnbuckle later. It's still tight enough that they won't adjust themselves, but loose enough to make it easy to adjust later.