Blade balancing.
You're right about larger blades being more dependent on good balancing. I have about a 1925 GE fan. It is the big one with a 16" diameter blade-set. Right now it is in many pieces undergoing a very slow restoration but it was in running condition (barely) when I got it. The fan weighs about 30 pounds and the original steel blades probably weigh about 5 pounds (the original blades are severely damaged so I am installing brass blades in good, and shiny, condition). When I ran the fan, it was so off balance that the whole fan actually jumped around on the table. Depending on speed, it could launch itself up in the air a little bit and then THUD back down on the table in time with the vibration.
I have restored a few fans and when properly balanced they are a dream. They move a ton of air very quietly. I ran my 1947 GE Vortalex 12" for days and days without a rest and it never slowed or stopped. It's still a great runner. All I have done to it has been to refurbish the lubrication system and periodically change the oil.
What happened to industrial design?
Dave
