I had a question sent me the other day. "How do you balance blades?"
First let me say, there are better ways of doing this than my way, but I don't own a strobe light nor do I know how to use one. That being said, here goes....
I have a couple fans that when they came to my "Fan Family" (I like that better than collection) they would run okay, but they were so out of balance that they would walk across the floor on their own. After applying my method they work really well.
First thing you will need to do is remove the cage. Second, find some point on the motor that you can measure from. (I usually use the handle if there is one.) Then you rotate the blades, measure each one in relationship to the stationary point. This will give you some idea of which one is off. (usually there will be one critter that is straying distinctly bad) Once you have located the offender mark it with a sharpie or something with a little mark that is discrete. Then, and this is the difficult part, I use my hands, vise, or channel locks (depending on the blade/hub) cautiously to bend the blade slowly back into place ****VERY IMPORTANT**** Don't bend the blade itself. This is how blades are broken or creased, as you often see them. YOU MUST TRY TO BEND AT THE HUB.
This information is blade specific. If you have a cast iron hub, don't try this, it will break. If your fan's blades are brass, be very careful, brass is very easily bent.
This is the best I have for info on this topic. If you are still unsure of your abilities. I would suggest getting more information first or seeking a professional for assistance. There is nothing worse than destroying a fan with your own hands... GOOD LUCK!