Re: Another Original 2-Blade Fan Takes Its Toll
What is the point of making a steel reproduction 2 bladed fan requiring welding the blade to the hub? As we all know welding is the primary cause for the original fan to fail. Fact; welding produces small cracks no matter how careful or controlled the process is. The blades on the 2 bladed fan in our engines encounter many millions of cycles of bending loads during normal operation. The most vulnerable place for a failure to occur on a component of this type operating in this mode is at a welded joint. Over time the small cracks (micro cracks) within the weld zone begin to grow as the number of operating cycles continue to increase. Once the cracks reach a certain size and number the welded connection significantly weakens or fatigues to the point where it completely fails causing the blade to break away.
A good quality cast Al 2 bladed fan made in the good old USA is probably the best way to go.
Jack
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