re: Ceiling fan knocks when it’s turned on. How do you rebalance it?

What is knocking? If you can, gently push up on the end of the blades to see if there is any movement where they attach to the motor. Could be a loose fan blade. I had a loose blade and it would knock until it got up to full speed. Turns out the blade was loose and it was hitting the housing of one of the lights.