I had a customer ask how to use the Pigtail Bearings that I now sell. He, like many, are unfamiliar with them because they come from the “Indoor” Free Flight world – the microfilm guys.
They were developed (I don’t know by whom) to allow prop assembly changes. Because of the unique “Y” split in the rear support, a prop shaft (with a jog in the end) can be inserted and removed at will. They are called “Pigtail” because of this jog or bend in the hook end of the shaft.
Here are photos of how a prop assembly can be installed with these.