Thanks Pat. As Mitch said most of the fans can be installed with no problems, even if the balance isn't as perfect as it could be. I like to check the balance and make it as perfect as I can get it. Here is a picture of the first balancer I made using a pair of parallel rails. The problem with this one is the rails must be perfectly level while using it, so I installed a bubble level to help.
I much prefer the second one I made using a piece of aluminum channel and 4 small very low friction ball bearings. After I sold this one to Brent I had to make another one for myself. As I was walking around the Goodwill store I spotted a fancy brass candlestick holder for a couple bucks, and had the brilliant idea of using that instead of making another wood pedestal for the balancer.
I keep a plastic bag over the balancer to keep dust off the rollers and if the ball bearings show and resistence I'll give them a drop of light oil and spin them against the wire wheel to limber them up, just before I balance the fan. The top picture (bottom fan) shows the aluminum fan and where I drilled and filled with lead to balance. On the top steel original fan, if after making sure the blades are straight, it still need to be balanced I can add a little solder in the curved area of the blades. This way I can smooth it out so it isn't noticed.
I stuck an old shaft and impellor into a tuna fish can and poured in melted wheel weights to make a counter weight for the fan. The shaft must be smooth without pits and of course this must be balanced first before putting it to use.